Herbarium Explorations: Irreplaceable Repositories of Historical Plant Information Vital to a Wide Variety of Scientific Applications

In the U.S. National Herbarium at the Smithsonian’s National Museum of Natural History, botany department staff examine pressed and jarred specimens of algae.

By Marcia G. Yerman

The American Gardener, AHS

November/December 2017

 

IT’S EASY to be amazed and inspired by the vibrant, living collections of plants at public gardens and universities. But there are 400,000 species of plants and possibly millions of species of fungi on the planet—far more than all the public gardens in the world can display. The job of maintaining historical records of all those plants and fungi goes on largely out of public view, in archives known as herbaria.

 

“Herbaria serve as an encyclopedia of the Earth’s flora,” says Vicki Funk, Senior Research Botanist & Curator at the Smithsonian National Museum of Natural History (NMNH) in Washington, D.C. “They are really our only record of what’s been on the planet in the past, what’s here in the present, and what we predict into the future,” she adds. Yet many people don’t fully understand why herbaria are important. “There’s a misconception that the collections are just a bunch of boring dead plants, and that what we do is not science,” Funk says. “In reality, it’s not that at all. We collect specific things to answer specific questions.”

 

The specimens in herbaria are irreplaceable sources of information regarding the diversity of species and the habitats they come from. They play a critical role in taxonomy, systematics, anatomy, morphology, ethnobiology, paleobiology, and conservation biology. They can be used to confirm the identity of a newly discovered species, and provide locality data for conservation assessments. Specimens can document the effects of climate change on flowering phenology and provide material for DNA analysis and conservation genetics.

 

INSIDE A HERBARIUM

According to the Index Herbariorum, an online catalog of herbaria maintained by the New York Botanical Garden (see “Resources,” page 31), there are 2,885 herbaria worldwide containing approximately 375 million specimens. Of these, the William and Lynda Steere Herbarium at the New York Botanical Garden (NYBG) is the second largest herbarium in the world (the largest is at the National Museum of Natural History in Paris, France). It houses the most extensive  collection in North America with over 7.8 million preserved plant and fungal specimens, including samples from every continent.

 

This past summer, the NYBG hosted “What in the World is a Herbarium?” to showcase this lesser known side of its work. I toured the exhibit, which explored different aspects of the Steere Herbarium’s mission, from the collection of specimens and the process of preservation, to the history of the research of American botanist and inventor George Washington Carver, a former slave who spent much of his career researching alternative crops to cotton.

 

The theme of one wall, “Saving the Plants of the World,” outlined the efforts of NYBG’s staff to collect plant species in geographic areas from Myanmar (formerly Burma) to the Brazilian Amazon. From a diversity standpoint, Myanmar’s northern forest is exceptional; of the 6,000 plant species found there, 25 percent don’t exist anywhere else in the world. Specimens in the herbarium from places like these may represent the last bit of evidence that a species existed on Earth.

 

I also went behind the scenes with Matthew Pace, the assistant curator and an expert on  orchids of the New World.  In the climate-controlled herbarium stacks, I viewed with amazement historic specimens that included a plant collected on Captain James Cook’s first voyage, when he led an expedition to the South Seas beginning in 1768; a moss collected and documented by English naturalist Charles Darwin; and plants gathered by artist and explorer John J. Audubon, who used them to ensure the accuracy of the habitats depicted in his paintings of birds.

 

In addition to the historical significance of specimens like these, Pace stressed their importance to current research. For example, ethnobotanists can consult herbarium collections to examine plant use by societies around the world, and scientists on the ground can apply this knowledge while interacting with local populations to develop sustainable practices.

One of the most important components of herbaria collections is what are known as type specimens. These are the original individual specimens from a population that serve as the reference point for naming a new species, so they are vital for determining the correct application of a botanical name.

 

“Our whole system of nomenclature is linked to these herbarium specimens,” says Funk. “Everything that has a name must have a type specimen as a record of it.” The U.S. National Herbarium, for instance, holds more than 120,000 type specimens.

REVELATIONS FROM PRESERVED PLANTS

I left the NYBG’s exhibit with a whole new level of appreciation for the scientists who study dead plants. It was particularly encouraging to learn about the work occurring, both in the United States and elsewhere, to protect plant life in the face of climate change and other threats. Unlike the situation with endangered animals—especially the socalled charismatic megafauna such as pandas and elephants—the narrative around threatened plants is often under the radar.

 

Herbarium collections can reveal a lot about how climate change affects and will affect plants, explains Dennis Desjardin, director of the Harry D. Thiers Herbarium in San Francisco, California. “The presence or absence of a specific species in an area reflects environmental conditions at the time of collection, hence they can be used to evaluate climate change, competition, and other data pertinent to conservation efforts,” he says.

 

Gary Krupnick, a conservation biologist who is Head of the Smithsonian’s Plant Conservation Unit in Washington, D.C., points out that new ways to glean climatic insights from herbarium collections continue to surface. “Today, we’re using specimens in ways the original collectors could never have imagined,” he says. “For instance, a recent study by a team of scientists examined the protein content of pollen from specimens of Canadian goldenrod dating from 1842 to 1998, that are housed at the U.S. National Herbarium. They found that as atmospheric carbon dioxide levels increased, the protein content of the pollen decreased. Thus, an increase in carbon dioxide emissions over the last several decades has made a key food source for bees less nutritious than in the past.”

 

Desjardin is also particularly excited about what herbarium specimens can tell us on a molecular level. “Each specimen contains DNA that can potentially be sequenced, so they provide genetic information for understanding speciation and evolutionary relationships,” he says. Genetic sequences for individual plant species are being logged into online databases such as GenBank, so that researchers everywhere can access and analyze the data. This information has widespread applications in fields such as medicine, pharmacology, and bioindustry. 

 

COLLABORATIVE EFFORTS

Along with genetic sequences, technological innovations of the Digital Age have made it possible to digitize herbarium specimens and make them more widely accessible online. This has encouraged herbaria to “become more collaborative,” says Funk, who has been working at the U.S. National Herbarium at the Smithsonian for more than 36 years.

“It used to be that all the collected specimens went back to major herbaria,” she says. “Now the plant collections are shared with the country of origin.  Also, many programs are digitizing the specimens and the literature so people in places other than major cities with big herbaria have access to resources they never had before.” Digitization also provides a cost-effective alternative to having to borrow a specimen across long distances or send a researcher to view it in person. And now that individual institutions and researchers are no longer the sole holders of specialized regional or plant family collections and data, there is greater participation and higher standards in academic research, Funk adds.

 

Among the many herbaria moving toward this free flow of information are the ones at NYBG and Smithsonian, which have uploaded their collections to a free searchable database (see “Resources,” this page). Full documentation accompanies the high-resolution images. Every month, thousands of records are uploaded. In 2013, the NYBG reached the milestone of its two-millionth specimen for digitization, which turned out to be the purple pitcher plant (Sarracenia purpurea), a carnivorous plant native to eastern North America. The U.S. National Herbarium hit the same digitization milestone in 2016.

 

While new technologies continue to advance our ability to tackle complex conservation issues and expand our scientific knowledge, herbaria provide an essential foundation for this critical work. “Though a third of the world’s plant species are in inexorable decline and headed to extinction, we have the skills and ability to save the majority if we work hard to do so,” says James S. Miller, Senior Vice President for Science and Conservation at the Missouri Botanical Garden in St. Louis, which holds the second largest collection of plant specimens in North America in its herbarium.“The herbarium is the catalog that we work against. We need the whole list of the world’s plant species before we can decide which need attention to ensure their future survival.”

 

See full article with many informative photos at:  http://ahsgardening.org/uploads/pdfs/Herbarium_TAG_ND17.pdf

Heritage Garden Club Shares Holiday Gratitude with Triangle First Responders

 

The Heritage Garden Club of Durham continued its annual holiday tradition of making beautiful floral arrangements to gift a handful of Triangle First Responders and public workers.

Heritage Garden Club members met in early November at the home of Martha Sanderford and got busy in her family's garage wiring and creating fresh holiday arrangements with natural plants and materials brought from their own yards. Each arrangement was tagged with a thank you from the Heritage Garden Club.

Eight holiday arrangements were made and delivered to:  different branches of the Durham Co. and Orange Co. Libraries, Fire Stations and EMS Stations in Durham and Orange Co. as well as the Semora Volunteer Fire Department.

 

Photos by the Heritage Garden Club. 

Growing Home Orchards in North Carolina

With the proper conditions, home gardeners in North Carolina can also grow certain types of cultivar fruits.

Growing tree fruit in the home garden or yard can be a rewarding pastime. However, careful planning, preparation, and care of the trees are essential for success. This publication tells you what to consider before planting, how to plant your trees, and how to take care of them to ensure many seasons of enjoyment.

 

Fruit Selection

Selecting the type of fruit to grow is the first step in tree fruit production. To begin, you need to know which tree fruit can be grown in North Carolina.

 

Your region's climate determines the type of fruit you can grow successfully. The climate must be compatible with the growing requirements of the selected fruit crop. To take an extreme example, a tropical fruit such as the banana simply cannot survive in North Carolina. Bananas require a warmer climate and a longer growing season. Other tree fruit that may look promising in the glossy pages of mail order catalogs are also destined to fail if grown in incompatible climates. Climatic conditions vary greatly from one region to another in North Carolina, so make sure that the fruit you choose can grow successfully in your area.

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Table 1. Potential tree fruit crops for North Carolina.
 

Fruit	Location	Varietal Considerations	Management
Apples	Throughout North Carolina	Most varieties will grow in North Carolina	Moderate
Asian Pears	Throughout North Carolina	Plant fire blight-resistant varieties only	Moderate
Chestnuts	Throughout North Carolina	Chinese and Chinese-American hybrids	Low
Figs	Eastern North Carolina and southern piedmont	Select varieties that set fruit without pollination	Low
Nectarines	Throughout North Carolina except at higher elevations	Select varieties that require at least 750 hours of chilling	Very high
Peaches	Throughout North Carolina except at higher elevations	Select varieties that require at least 750 hours of chilling	High
Pears	Throughout North Carolina	Plant fire blight-resistant varieties only	Moderate
Pecans	Eastern North Carolina and southern piedmont	Select varieties suitable for North Carolina conditions	Low
Persimmons	Eastern North Carolina and southern piedmont	American and Oriental are suitable	Low
Plums	Throughout North Carolina	Use late-blooming varieties	Moderate

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Fruit crops that can be grown in North Carolina are listed above in Table 1, along with additional information that will help to ensure success. Tree fruits that are not included in the list may grow in North Carolina, but few consistently produce quality fruit. For example, apricot and cherry trees can grow in certain areas where the climate is favorable, but they must be carefully managed and usually do not bear fruit consistently.

 

Note also that different crops require different levels of management. Low-management crops such as pecans, figs, and persimmons require little attention to training, fertility, or insect and disease control. On the other hand, peaches and plums require intensive management.

 

Site Selection

Selecting a good site for your fruit trees is crucial to their success. A number of factors should be considered (Figure 1a and Figure 1b).

 

Soil Type and Drainage

Plant fruit trees in well-drained and fairly fertile soil. Avoid poorly drained soils. A tree's root system grows throughout the year. Water that remains standing in the root zone (18 to 24 inches deep) at any time during the year can drown the tree. During the growing season, standing water can drown some types of fruit trees in just three days. Poorly drained soils also promote the growth of root rot organisms.

 

When poorly drained soils cannot be avoided, problems may be alleviated by planting the trees in raised beds (Figure 3). The beds are formed by shaping well-drained topsoil into beds 18 to 24 inches high and 4 to 5 feet wide. Raised beds have been used successfully in both backyard and commercial orchards. Trees grown in raised beds must be irrigated more frequently during the growing season because the beds present a larger exposed surface area from which water can evaporate.

 

Soil Fertility

It is also important to consider soil fertility and acidity. Ideally, the soil pH should be around 6.5, but North Carolina soils are more typically acidic. Acidic soils reduce the amount of nutrients available to the trees. When this happens, fertilization does not benefit the trees but results in runoff or leaching. To alleviate the problem, it will be necessary to add lime to the soil to reduce the soil pH.

Before planting, collect soil samples for analysis. Soil samples should be taken from two depths; the first from the top 8 inches of soil and the second from the 9- to 16-inch depth.

 

Soil fertility analyses are free in North Carolina. Contact your county Cooperative Extension agent for instructions on collecting and submitting soil samples and for the necessary forms and sample boxes. Test results will be returned to you with recommendations for fertilization and liming. Once the test results have been received, the soil should be amended with the recommended materials, which should be worked into the soil before trees are planted.

 

Air Drainage

Adequate air drainage is as important as proper water drainage. In North Carolina, spring frosts and freezes are common, and a small difference in elevation can mean the difference between a full crop and no crop at all. Remember that cold air is heavier than warm air and settles in low areas, so choose a site that allows cold air to flow downhill away from the trees. Select higher sites with an unobstructed, gradual slope. Avoid low sites, which are commonly known as frost pockets.

 

Sunlight

Plant fruit trees in areas that receive full sunlight. Avoid areas shaded by taller trees, houses, or buildings (Figure 1a).

 

Most fruit tree buds require 30 percent sunlight to produce high-quality fruit. Although the exterior of a tree may receive full sun, sunlight can be reduced by one-half just 12 inches inside the canopy of the tree. Eighteen inches into the tree canopy, light may be reduced nearly 75 percent, which is below the level needed for successful fruit production. Partially shaded trees can also have increased disease problems.

 

Nematodes

Nematodes are microscopic worms that live in the soil. Several types of fruit trees, including peach, plum, and figs, can be damaged or destroyed by nematodes.

 

An inexpensive soil test can be conducted to check for nematodes. For information, contact your county Cooperative Extension agent. The test results will be returned with recommendations for your crop. Avoid soils with high nematode populations. Soils with unacceptable nematode populations can be treated with a soil fumigant. However, most fumigants must be applied by a licensed pesticide applicator and can be costly. Contact your county Cooperative Extension agent for specific recommendations.

 



Figure 1a: Poor site selection. Fruit trees should

 not be planted in areas shaded by houses, buildings,

 or other trees. They also should not be planted

 near fences or hedges, as these keep

cold air trapped around young trees. Nickola Dudley

Figure 1b: Well-selected site. All fruit trees are

planted away from barriers and in areas

 that receive sufficient light. Nickola Dudley

 

                                                                        

 

                                                                      

Variety Selection

After selecting the fruit and the planting site, you must choose the variety of fruit to plant. Novice growers often try to plant the same varieties that they see at their local grocery stores. Many times, however, these fruit are produced in areas with different climatic conditions from those in North Carolina. The result, at best, is fruit that looks much different than expected. At worst, the variety will fail to produce a crop. Plant varieties that are known to grow well in your region. Check temperature requirements and chilling factors before purchasing your trees. Table 2 lists some of the fruit varieties recommended for North Carolina.

 

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Table 2. Variety recommendations for North Carolina.
 

Fruit	Recommended Varieties	Pollination Notes	Disease Notes	Other Considerations
Apples	Gala, Ginger Gold, Jonagold, Empire, Red Delicious, Golden Delicious, Crispin (Mutsu), Stayman, Rome, Fuji	Requirements vary. Some varieties are self-fruitful. Others require pollination (see note 1).	Summer rots are the most serious disease problems and can destroy an entire crop. No varieties are resistant. Some varieties are resistant to apple scab, powdery mildew, cedar apple rust, or fireblight. These include Redfree, Prima, Priscilla, Jonafree, and Liberty.	In warmer regions, red varieties may not color well.
Asian Pears	Twentieth Century (Nijisseiki), Nititaka (pollen source), Shinseiki (New Century), Chojuro.	At least two varieties are needed to ensure adequate pollination.	Fire blight is the biggest concern.	Asian pears are very crisp and juicy.
Chestnuts	Chinese: Nanking, Meiling, Kuling, Abundance, Crane Chinese-American Hybrid: Revival, Carolina, Willamette	All require pollination from another variety. Plant at least two varieties of the same type to assure optimal nut size and production.	Most Chinese and hybrid chestnuts are highly resistant to the chestnut blight fungus.	Many people prefer the hybrid chestnut varieties, citing superior quality over the Chinese varieties.
Figs	Celeste, Brown Turkey, Brunswick/Magnolia (for preserves), Greenish, Marseille.	Only varieties that do not require pollination can be grown in North Carolina.	No serious disease problems except nematodes.	Fruit may drop prematurely as a result of drought or excessive shade, moisture, or fertilization.
Nectarines	Summer Beaut, Sunglo, Redgold, Flavortop, Fantasia, Carolina Red (see note 2).	Self-fruitful. Do not require pollination by other varieties.	Nectarines should be planted only on Lovell or Halford rootstocks to avoid premature death. The lack of hair on nectarines makes the fruit more susceptible to diseases than peaches, and a multipurpose fungicide and insecticide spray program will be required.	Many varieties were developed in California and may not do well in North Carolina.
Peaches	Redhaven, Norman, Carolina Belle (white-fleshed), Winblo, Contender, Summer Pearl (white-fleshed), Cresthaven, Encore, Legend. (Many varieties are the result of a peach breeding program at NCSU and have been developed for North Carolina (see note 2)).	Self-fruitful. Do not require pollination by other varieties.	A multipurpose fungicide and insecticide spray program will be needed during the growing season.	Only varieties that require 750 hours of chilling are recommended.
Pears	Moonglow, Magness (not a pollen source], Kieffer, Harrow Delight, Harrow Sweet, Harvest Queen, Seckel.	At least two varieties are recommended to ensure adequate pollination.	Plant only fire blight-resistant varieties.	Pears bloom earlier than apples and should be planted on higher sites.
Pecans	Type I: Cape Fear and Pawnee. Type II: Stuart, Forkert, Sumner, Kiowa, Gloria Grande	Pollination by another variety is essential. One variety from each of the two groups must be used for pollination.	Scab is the most serious disease in North Carolina. However, a fungicide spray program is usually not practical.	Careful variety selection is essential to avoid frost or freeze problems and to allow a long enough season for maturation.
Persimmons	Fuyu, Jiro, Hanagosho (very good pollen source). (Only large-fruited Oriental persimmons are recommended for North Carolina.)	Pollination is not required for fruit set but is recommended.	No serious disease problems.	If nonastringent varieties are planted, fruit may not be suitable for eating until they are fully mature and their flesh is soft.
Plums	Japanese: Methley (self-fruitful), Byrongold, Burbank, Ozark Premier (may bloom early). European: Bluefre, Stanley, Shrophire (Damson) (see note 2)	Some varieties are self-fruitful, but planting two varieties is recommended.	A multipurpose fungicide-insecticide spray program will be needed during the growing season.	Later blooming varieties should be selected to avoid damaging spring temperatures.
Note 1. Pollination requirements for apples vary with variety. For varieties requiring cross-pollination, it is recommended that at least two varieties with overlapping bloom periods be planted together. For self-fruitful varieties, pollination by another variety will increase yield and quality. Note 2. To break bud and grow properly in the spring, peaches, nectarines, and plums must be exposed to temperatures in the 40°F range for a required number of hours during the dormant season. This period is referred to as the chilling requirement. In North Carolina, varieties with chilling requirements of at least 750 hours are recommended to prevent trees from blossoming too early in the spring, which increases the risk of freeze damage and resultant crop loss.

 

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Rootstock Selection and Tree Spacing

Almost all commercially available fruit trees have been budded or grafted; that is, the top portion, or scion, of the desired fruit variety is attached to the root system, or rootstock, of a different variety. Trees are grown this way because some popular varieties grow and crop better on rootstocks other than their own. In some cases, the rootstock is more resistant to certain troublesome diseases. In the case of apple trees, the rootstock can be chosen to limit growth, producing trees that crop well and are easier to manage than full-sized trees. The choice of rootstock is very important for some fruits, such as apples, but not of much consequence for others.

 

Apple trees are grown on a wide variety of rootstocks. These are called size-controlling rootstocks because they control the size of the tree; however fruit size is not reduced (Figure 2). In general, the smaller the tree, the sooner it will bear fruit after planting. Table 3 lists the rootstocks commonly used for apple trees and indicates their effect on tree size, using the "seedling" or standard rootstock as the basis of comparison. Thus, for example, the M.9 rootstock will produce a nonspur-type tree that is only 35 percent as large as it would be if grown on a seedling rootstock. The table also lists the time required for the trees to reach bearing age and the degree of rootstock resistance to two important diseases.

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Table 3. Commercially available apple rootstocks and their characteristics.

Rootstock	Percentage of Seedling	Tree Size as Percentage of Seedling (Spur)a	Fruit Bearing Age (Years)	Resistance to Crown Rot	Resistance to Fire Blight
Seedling	100	80	6-10	Medium	High
MM.111	85	70	4-6	Medium	Low
MM.106	80	70	3-4	Very Low	Low
M.7a	70	60	3-4	Medium	High
M.26	50	40	2-4	Medium	Very Low
Mark	45	35	2-3	Medium	Low
M.9	35	20	2-3	Medium	Low
a See Figure 2.

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Two categories of growth habit are included in the table: spur and nonspur. Trees with a spur-type growth habit bear the majority of their fruit on very short branches called spurs. Nonspur varieties produce fruit on longer branches. Since spur-type varieties have fewer long branches, the trees are more compact.

 

Because the choice of rootstock affects the size of the trees, it also affects the optimum spacing between the trees. Table 4 gives the recommended distance between trees for both spur and nonspur varieties. Note that very vigorous varieties should be spaced farther apart.

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Table 4. Recommended planting distances for apple trees grown on size-controlling rootstocks.
 

Rootstock	Distance Between Trees (feet)
	Nonspur Varieties	Spur Varietiesa	Very Vigorous Varietiesb
Seedling	18-25	12-16	25-35
MM.111	14-18	9-12	20-25
MM.106	12-16	8-11	17-22
M.7a	10-14	7-9	14-20
M.26	8-12	5-8	11-17
Mark	6-8	4-5	8-11
M.9	4-8	3-5	6-11
a For spur-type varieties such as Redchief Red Delicious, Starkrimson Red Delicious, Lawspur Rome, and Oregon Spur. b For very vigorous varieties such as Rome Beauty, Granny Smith, and Jonagold.

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Apple trees on rootstocks of a size class smaller than M.7a bear fruit while they are still very young. They should be supported by stakes to promote optimum growth and to help support the fruit load in the early years. Use 10-foot stakes and drive them 2 feet into the ground. Stakes are commonly made from 1-inch-diameter aluminum electrical conduit or 3-inch-diameter wooden posts. Tie the tree loosely to the above-ground portion of the stake. Strips of plastic or heavy-duty canvas or cloth can be used as ties. Do not use materials that will restrict tree growth or girdle the tree.

 

Peaches, nectarines, and plums are also affected by choice of rootstock. In the Southeast, trees are susceptible to peach tree short life (PTSL), a condition that causes sudden death of the tree after only four or five years of growth. With proper rootstock selection, nematode suppression, and cultural practices, the threat of this condition can be minimized. At present, only trees grown on Lovell or Halford rootstock are recommended for use in North Carolina. Trees grown on these rootstocks should be spaced 20 feet apart. Spacing recommendations for other fruit trees are given in Table 5.

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Table 5. Spacing requirements for other tree fruits.
 

Fruit Crop	Minimum Spacing Between Trees (feet)
Asian Pears	20
Chestnuts	40
Figs	10
Pears	20
Pecans	70a
Persimmons	15
a At maturity, approximately 20 years

 

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Figure 2. Tree size shown as a percentage of the size the tree would reach if grown on a seedling, or standard, rootstock. Nickola Dudley

        

Planting

The best planting time in North Carolina is late fall or early winter. The roots will then be able to grow through the winter, resulting in greater tree growth during the first season, which ultimately leads to larger trees. Young fruit trees are commonly shipped "bare root" with the exposed roots wrapped in moist sawdust. Plant the trees as soon as possible after purchase.

 

To plant a tree, dig a hole twice the size of the root system. The sides of the hole should be loose, not packed down by the force of the shovel. Cut off damaged roots at the point of injury. Shorten roots that are especially long and will not fit in the hole. Roots that are not shortened will wrap around the tree hole and eventually girdle the root system, reducing tree growth in later years (Figure 3).

 

In Figure 3, the figure on the left shows an improperly planted fruit tree. The hole is too narrow and shallow, forcing the roots to be wrapped in the hole, which may eventually girdle the tree. The graft union is also planted below the soil surface, which will negate the effect of the rootstock. The raised bed is not wide enough or deep enough to be of much benefit. The figure on the right shows the correct way to plant fruit trees.

 

When planting a grafted tree, be sure that the graft union is 2 inches above the soil. If the graft union is below the soil surface, the top portion or scion will grow roots and negate the effect of the grafted root system.

 

After the tree is in place, fill the hole with native soil, not potting soil. Adding organic matter or mulch to the soil can promote growth if these materials are mixed well with the soil. NEVER add fertilizer to the planting hole. Fertilizers are very caustic and can burn and kill the roots of young trees. After you have filled the hole, be sure to water the area well.

 

During shipping, handling, and planting, roots are damaged. After planting young trees, prune the top of each tree. Pruning the tree top balances the root system and promotes vigorous growth in the spring. When working with unbranched trees, cut the tree off approximately 32 inches above the ground. For larger trees, remove ¹⁄₃ of the top of the tree.

 

Figure 3. Nickola Dudley

                                

Weed Control

Weeds or grass growing between or under fruit trees compete for soil nutrients and moisture, reducing tree growth.

 

Keep all vegetation under the trees controlled up to the drip line (the circle formed by the outermost branches of the tree). Avoid using mechanical cultivation to eliminate weeds because tree roots near the surface will be destroyed in the process. Weed whips are especially harmful. If the cutting line strikes the bark of the tree, it can crush layers of cells under the bark and girdle the tree without any visible signs, such as broken tree bark.

 

Herbicides are an effective alternative, but be careful to follow the label directions and keep the herbicides off the tree.

 

Another alternative is to mulch around the tree. A layer of mulch 4 to 6 inches deep will control weeds and conserve soil moisture. Note, however, that mulch can provide cover for voles or mice. These rodents burrow under the mulch and frequently gnaw tree trunks or roots, girdling the tree and killing it or impeding its growth. When using mulch, check for rodent pests. Prevent problems by placing guards around the base of the trees or use traps to control these pests. It may also be beneficial to pull the mulch back 1 foot around the tree trunk in the early fall.

 

Insects and Disease Control

Unless properly managed, insects and diseases can seriously damage fruit trees and their crops.

Pests can be controlled with commercial pesticides, and moderate control may be achieved using organic controls. Garden centers offer many materials, including multipurpose insect and disease control products. Treatment must be started before problems become severe, causing serious damage or crop loss. It is important to identify pests and diseases accurately so an effective treatment can be selected. Contact your county Cooperative Extension agent for assistance in identifying pests and for recommended control measures. Pest problems can also be reduced through proper sanitation. Remove and burn or bury dead, diseased, and damaged wood and fruit as soon as possible. Also, remove the leaves after they have fallen in autumn. Do not use the leaves as mulch. The infected leaves, wood, and fruit can provide a habitat in which insects and disease-causing organisms can overwinter. By taking time to maintain orchard sanitation, you can reduce insect and disease problems significantly. For additional information on disease and insect control, contact your county Cooperative Extension agent.

 

Fertility

Tree fertility requires attention throughout the life of the tree, not just at planting time. However, applying fertilizer routinely without knowing whether it is needed can result in poor fruit quality and excessive tree growth. It can also waste money and contribute to environmental pollution. Annual soil analyses can keep you informed about the nutrients in the soil and the soil acidity. In addition to soil analyses, simple observation of the amount of vegetative growth can help in managing soil fertility. Trees with less than 10 inches of current season's growth on lateral branches may need fertilizer. On the other hand, trees with greater than 18 inches of growth may not need fertilizer for several years. Excessive tree growth can promote some pest problems.

If you must fertilize without benefit of a soil test or other information, a useful rule of thumb is to apply ³⁄₄ to 1 pound of 10-10-10 fertilizer for each year of tree age. When fertilizer is used, it is usually applied in late winter. Fertilizer should be broadcast on the soil surface both inside and outside the drip line of the tree. Keep fertilizer at least 6 inches away from the trunks of young trees.

 

Fruit Thinning

Apples, nectarines, peaches, pears, and Asian pears must be thinned early in the season to prevent overproduction, which can result in smaller fruit, increased tree breakage, and in-creased insect and disease problems. A heavy crop also reduces the chances for an adequate crop the following year.

Fruit should be thinned when they are about the size of a nickel. Remove enough fruit so that the remaining ones are spaced about 4 to 6 inches apart along the branch (Figure 4). Even though it may look like very few fruit remain, the increased fruit size at harvest plus reduced risk of tree breakage and improved prospects for next year's crop will more than compensate for the reduced number of fruit.

 

Figure 4. Fruit thinning. Top drawing: unthinned apple branch. Apples, pears, peaches, nectarines, and Asian pears should be thinned so that they are approximately 4 to 6 inches apart, as shown in the lower drawing. Nickola Dudley    

                      

Training and Pruning

To ensure abundant harvests, you will need to train and prune your fruit trees regularly. For additional information on cultural practices, see Cooperative Extension Service publication AG-29, Training and Pruning Fruit Trees in North Carolina.

 

Summary

If you follow the suggestions in this publication and monitor your trees carefully, you will find that growing tree fruit can be a rewarding experience. As with any activity, experience will give you confidence to prune, train, and thin fruit trees properly. Remember that fruit trees, if properly cared for, will last and produce quality fruit for many years. Proper care is especially important during the first five to six years when the trees are not bearing fruit but the tree structure is developing.

 

Additional Sources of Information

The following materials may be purchased by writing to the address listed below each publication.

Extension Horticultural Science

Peach Production Handbook

Published by

Georgia Cooperative Extension Service

Agricultural Business Office

Conner Hall, Room 215

The University of Georgia

Athens, GA 30602

For sale only ($20).

Pecan Production in the Southeast; A Guide for Growers

Published by

Alabama Cooperative Extension Service

Head, Information Services

Alabama Cooperative Extension Service

Auburn University, AL 36849-5623

For sale only ($31).

 

Author:

Michael Parker, Extension Horticulture Specialist and Associate Professor (Tree Fruits/Pecans)Horticultural Science                                                               

Publication date: Jan. 1, 1999, AG-28;  Last updated: March 28, 2017

https://content.ces.ncsu.edu/producing-tree-fruit-for-home-use

BOOKS: Ancient Oaks in the English Landscape

Ancient Oaks in the English Landscape 

Author: Aljos Farjon
Hardcover: 348 pages
Publisher: Royal Botanic Gardens, Kew (October 15, 2017)
ISBN-10: 1842466402
ISBN-13: 978-1842466407

The ancient native oaks of England are a national treasure, beautiful and beloved. And England has more of them than the rest of Europe combined. How did that happen? How, as Europe was deforested over the course of centuries, did England manage to preserve so many ancient trees?

Ancient Oaks in the English Landscape tells that story. It begins with the Norman Conquest in 1066. The Normans, and the nobility they put in place, created Royal Forests, chases, and deer parks where only the nobility could hunt or keep deer—and where, to protect that game, it was forbidden to cut trees. Thus, centuries before the modern conservation movement, the trees were preserved.

Other historical and social factors enabled that preservation to continue long after the decline of royalty. Private ownership of thousands of parks and estates, the ready availability of timber from overseas, and, crucially, the absence of major wars and their accompanying destruction brought the ancient forests into our era. By the time modern forestry truly took hold in England after World War I, it was too late to destroy the now worthless old and hollow oaks.

Bringing together history and science, Aljos Farjon tells this compelling story, illustrating it with stunning photographs and maps. The result is a beautiful, fitting celebration of England’s ancient oaks and the biodiversity they represent and foster.

https://www.amazon.com/Ancient-English-Landscape-Aljos-Farjon/dp/1842466402/ref=sr_1_20?ie=UTF8&qid=1510793841&sr=8-20&keywords=english+oak+tree+book

Garden Spotlight: Five Spectacular Gardens on Italy’s Lake Como

Villa Monastero, Lake Como, Italy. Stillman Rogers Photography.

By Barbara Radcliffe Rogers

GardenDestinations.com

 

Ever since the ancient Romans escaped the summer heat in villas overlooking Lake Como, travelers have loved this scenic Italian lake. With the craggy Alps for a backdrop, a unique microclimate where topical plants thrive, and a long history of lavish summer estates, Lake Como is surrounded by some of Italy’s most beautiful gardens. Lush foliage and brilliant flowers frame views across the lake to peaks that stay snow-capped well into summer. The shore rises steeply, so gardens cascade above the water, and descend in terraces decorated by statues and fountains.

 

Villa Carlotta

The climate is especially mild on the central western shore, known as the Tremezzo Riviera. Here in the late 17th century, a marquis from Milan built a villa, now called Villa Carlotta, surrounding it with a terraced garden typical of the Italian style. You can recognize its geometric symmetry studded with fountains and statues. Also close to the villa you’ll find the oldest and rarest of Villa Carlotta’s famed camellias.

The gardens were later extended into the park you can stroll through today, redolent of the Romantic era, with sweeping vistas, woodland paths and venerable cedars and sequoias. In 1843 Princess Carlotta of Prussia added long alleys of azalea and rhododendron. Today Villa Carlotta’s gardens are most famous for these. As many as 150 different varieties of azalea, bloom in April and May against a backdrop of towering Rhododendron arboretum, native to the Himalayas.

Just as you think you’ve seen them all, another of the villa’s gardens appears – a bamboo forest, a rock garden of succulents (even in this mild micro-climate these winter in a greenhouse), a valley of ferns, and artfully placed viewpoints over the lake. Inside the villa is a collection of sculpture that includes several of Canova’s best known works. Within walking distance along a shore promenade is the Grand Hotel Tremezzo, with a lush terraced garden of its own.

 

Villa Balbianello

The baroque Villa Balbianello, built for a 18th-century cardinal, crowns a high, narrow point to the south. The shape of the land and its steep shoreline made it impossible to surround the villa with Italianate or English-style gardens, but this unusual terrain was turned to advantage. Instead of concentrating on the plants as focal points, its designers used the scenery as the focus, creating gardens to frame it from every angle.

Visitors arrive by boat from Lenno, and climb a winding path through immaculately groomed grounds planted with sycamore, pine and ilex. On a terrace below the villa, life-sized statues and giant flower-filled urns top a stone balustrade, framing views of the lake, the wooded shores, distant mountains and surrounding villages. From late April through mid-June azaleas and rhododendrons are in full bloom. Movie-goers may recognize the villa’s loggia as the scene of Queen Amidala’s wedding in Star Wars or from the James Bond film, Casino Royale.

The attraction of Villa Balbianello is not so much its horticulture as the way plantings are combined with sculpture and architectural features to adorn the precipitous point and to perfectly spotlight scenery that unfolds in a constant progression. No matter where you stand the view is click-worthy.

 

Villa Serbelloni

Across the lake from Tremezzo (a ferry shuttles between them) is Bellagio, on the promontory that separates the two arms of the Y-shaped lake. Water almost surrounds the town, which climbs up the hill along steep lanes that turn into staircases. Above, Villa Serbelloni sits surrounded by 19th-century Italianate landscaping that gives perspective to the long vistas on three sides. Unlike Villa Balbianello’s more intimate views of nearby wooded shores and villages, Villa Serbelloni’s are distant and expansive. Instead of framing them, the successive garden terraces give them depth, highlighting their grandeur.

More than 10 miles of paths and avenues lead through terraced beds and borders of rare and exotic plants. The lower slope is an informal garden park, and above the villa a wooded hill rises to a scenic belvedere. Between are curving terraces of formal beds, pruned shrubs and English rose gardens bordered by boxwood.

Unfortunately, you cannot wander at leisure to enjoy the gardens. Access is only by tours, reserved at the Promobellagio office in Bellagio. The 90-minute tours are largely spent in the steep climb to the viewpoint at the top, leaving little time to smell the roses in the gardens below.

 

Villa Melzi d’Eril

In the town, a quite different garden stretches along a rare level spot of Como’s shore. The elegant and manicured grounds of Villa Melzi d’Eril seem designed for leisurely strolls, more for pleasure and less for horticultural show. Their botanical interest is in the wide variety of trees – more than 50 different species – planted in an uncluttered arrangement with paths winding among them. Maps of the garden include a detailed numbered list of the trees with common and botanic names.

Designed in 1808, the gardens are open and uncluttered, decorated with occasional statues that include one of the goddess Pacht brought back from Egypt by Napoleon, who was a friend of the owner. Hidden among the trees are a Japanese garden and a water garden. A Moorish-style pavilion overlooks the lake, surrounded by cypresses, Michoacan pine (Pinus devoniana) and dwarf palms (Chamaerops humilis).

At the far end stands a neoclassical villa with a chapel and an orangerie, where there are often art exhibits. Although flowers are not the specialty here, like other nearby gardens, these are beautiful in the spring when azaleas and rhododendron are in bloom.

 

Villa Monastero

The fifth notable garden overlooking Lake Como couldn’t be more different from Villa Melzi’s gentle green landscape. Farther north, on the eastern shore, the village of Varenna clings to a steep mountainside, and the 16th-century Villa Monastero lies directly below the narrow main street. The almost vertical garden beside it, planted in the 20th-century, stretches in narrow terraces along more than a mile of steep shore. The plants are a mix of native and exotic, and architectural elements range from a neo-Moorish pavilion to an Italian Renaissance-style loggia.

Rows of cypresses, evergreen hedges and cedars of Lebanon (Cedrus libani) keep the narrow flower beds in line, while more ethereal shapes, such as the fan-like Mexican blue palm (Brahea armata) soften the effect. Among these and the citrus trees grows a remarkable collection of roses, while wisteria creates lavender cascades. Where Villa Melzi’s garden is in shades of green, Villa Monastero’s is a riot of color that changes through the growing season.

 

WHEN YOU GO:

Gardens are not the only attractions on Lake Como. You’ll find art, walking trails, historic sites from the Romans to World War II, even a natural chasm where a river has carved a swath of fantastic shapes out of solid stone. Pastel villages are filled with restaurants and cafes with lakeside terraces, and many of the fine villas are now hotels. Bellagio is a good base at the lake’s center.

Lodging options there range from the opulent Grand Hotel Villa Serbelloni, not to be confused with the gardens, to cozy family-owned guest houses. Dozens of boats a day shuttle between towns, making any point on the lake an easy and inexpensive day trip.

 

See more photos and full article:  http://www.gardendestinations.com/five-spectacular-gardens-on-italys-lake-como/