---

---

---

Chinese Chestnut
They grow in zones 5-8 and will usually survive in sheltered spots in 4b. self-unfruitful; two or more varieties or seedlings must be planted to assure production of nuts.

The soil should be well drained, slightly acid, and humusy. Although trees planted in poor soil will produce nuts, they are much inferior to the nuts of trees planted in good soil. Give each tree a space 50' in diameter.

Fertilize newly planted trees very lightly after they put out growth. In subsequent years, give the trees a 10-10-10 fertilizer in early spring at the rate of 2 cups per inch of trunk diameter.

Chestnut weevils are the worst insect pests. Control by spraying* in August at 2 week intervals or when harvesting drop nuts in a bucket of water. The unaffected nuts will sink, throw the floating nuts away. If nuts are left on the ground the insect population will increase causing more damage yearly.

Chestnuts are harvested when the burs in which they are enclosed open and the nuts fall to the ground. Occasionally, however, the burs fall without releasing the nuts; in which case, you must open them by hand. Pick up the nuts every day, because they deteriorate if left in the sun. They must then be cured for three to seven days-until they feel a little soft- in order to reduce their moisture content and increase their sugar content. Placing them in a shady, airy place either in trays of in open containers does this.

Store nuts in ventilated plastic bags in the fresh-food compartment of your refrigerator. Large quantities of nuts can be mixed with barely damp peat, placed in light plastic bags and stored in a garage or basement at temperature just above freezing (this storage method is preferred if chestnut weevils are known or thought to be present). They will keep for months.

* At this time we do not know what spray to recommend. Please consult an extension agent.

Heartnuts
Heartnuts (Juglans ailantifolia var. cordiformis) have a valentine heart shaped nut and kernel. The tree is very pretty with lush foliage, even more tropical looking than Ailanthus, tree of heaven. Heartnuts are very hardy and mature trees are growing in Montreal with some winter damage. Heartnut trees are low headed, spreading laterally from a single short trunk. They are much more ornamental than the American Black Walnut, which is erect and limby. Heartnuts are the most disease resistant trees of the walnut family and should hold their leaves well into fall.

Heartnuts are adaptable to soil types and survive even in soils with a rich moist soil top, with high water table, hardpan or bedrock or cold subsoil underneath. heartnuts cast @ 70% shade. They make an excellent shade tree. Plant trees 30' apart.

Hulling heartnuts is easy. They are an easy addition to a gardeners diet because they are easy to grow, crack out of their hull easily and are delicious. Heartnuts store very well. In fact they imporve on their flavor reminiscent to the taste of brazil nuts.

Chinquapin
(Castanea pumila) also spelled "Chinkapins" and sometimes called dwarf or bush chestnuts are shrubs and small trees commonly found through the eastern, southern, and south-eastern United States. The plants usually bear one nut per bur and have burs (involucres) that open into two halves, such as a clam shell.

The Allegheny chinquapin, also called the American, common, or tree chinquapin, may well be our most mistreated and misrepresented native North American nut tree. It has been widely hailed as a sweet and edible nut; wood source for fuel, charcoal, fence post, and railroad ties; coffee and chocolate substitutes; for wildlife (birds an mammals); dwarfing rootstock for other Castanea spp.; and a blight-resistant taxon for hybridizing with other chestnut species; in addition, the root has been used as an astringent, a tonic, and to treat fevers.

Castanea pumila var. pumila is a large, spreading, smooth-barked, multistemmed shrub that is 2 to 4 m tall. Occasionally, there is but a single stem and the plant may reach 5 to 8 m. Large trees are sometimes found especially where humans have intervened and removed competing trees.

The Allegheny chinquapin is found in dry sandy woods and thickets from southern New Jersey and Pennsylvania, west to Indiana and Missouri , and south to Florida and Texas. It is usually ready for harvest in early September. Harvest must be prompt to gather nuts before wildlife (birds and small mammals) remove the entire crop.

Chinquapins are quite susceptible to Phytophthora cinnamoni root rot, so it is best to grow in well drained soil. Because of this root rot problem create a soil around the plant akin to its native habitat. Sod around the plant should be avoided. Stay away from a golf course mentality. Let the fall leaves stay under the chinquapin. Adding some top soil from the woods (around a gallon pot full) may help introduce beneficial organisms for the chinquapin. These preventive measures may help the plants natural defenses.

From present indications this tree will be well worthy of cultivation as an ornamental shade tree or bush. Even if we leave out of the account its rapid growth, productivenes, and delicious little nuts, which will be very acceptable for home use, if not possessing any great commercial value.

Filberts (also called hazelnuts or hazels)
Filberts are deciduous shrubs 6' to 30' which produce small nuts in the fall. They grow best in zones 8 and 9 in the Northwest, but to well in 6 and 7 pretty much throughout the country. Self-unfruitful; plant at least two varieties.

Culture, Plant filberts in a spot protected from bitter winter winds. The plants do not have tap roots, but put down very deep roots. They should have a deep, well drained, fertile, humus soil. In colder climates, where plants don't grow as large they need a space only 10 to 12 ft. across.

Because filberts are small trees, it is more practical to mulch then than larger nut trees. Use hay, leaves, or other organic material. The nutrients the mulch contributes to the soil is important to maintain of vigorous growth and good nut production. Further to promote growth, you should fertilize the plants with a balanced fertilizer such as 20-10-10. Apply ½ cup after the young plants are making growth; 1 cup the next year; and from then on increase the dosage by 1 cup a year until you reach 6. This is about the maximum for cold climates; but in milder areas, you can increase the supply 30 to 50 per cent.

Filberts start to bear two or three years after they are planted. They reach good production three or four years later, but are likely to become erratic after ten years unless they are pruned severely.

Nuts are harvested from the ground after they drop. If the husks remain, these must be removed. The nuts should then be spread out in a warm dry, shady place to dry.

Pecans
Pecans are a species of hickory. The sweet, brown, oblong nuts are produced in the fall. They grow in zones 5b - 9. Although pecans are self-fruitful, they are not reliably so because they often shed pollen at a time when the pistils are only partly receptive. Furthermore the nuts are of inferior quality. You should, therefore, plant two varieties- one that sheds its pollen early and the other that sheds it pollen late.

Pecans are divided into three groups: Eastern varieties are particularly adapted to the humid Southeast, although they do well farther west. They have above-average resistance to scab and other diseases. Western varieties grown from central Texas westward. They are well adapted to a fairly dry climate and alkaline soil, but they are very susceptible to scab and other diseases. Northern varieties mature their nuts in an unusually short time. They are tolerant of disease.

Pecans are very deep rooted, so they require a very deep soil. This should be a good loam, well drained and containing humus. Sandy and clay soils are much less desirable, although they can be improved to make the trees reasonably at home.

Undoubtedly the most important thing you can do is to water them frequently so that moisture reaches down to the bottom of the tap root. Mulching with a thick layer of hay or other organic material is recommended.

In subsequent years, water as necessary to maintain an even supply of moisture around the roots from the time the trees start making growth in the spring until the nuts are harvested in the fall. A lack of moisture at any time during this period will adversely affect the growth and output of the trees not only in the current year but also in the year following.

Fertilize newly planted trees when they put out growth with 1/2 cup of 10-10-10. Apply an additional 1/2 cup six to eight weeks later but not after July 30 in northern areas. Thereafter the trees can usually be fertilized with ammonium sulfate (or other nitrogen fertilizer). Apply this in early spring at the rate of about 1.5 cups per year of tree age. If trees are growing in an orchard where the ground is cultivated or mulched, the fertilizer should be broadcast over the entire root area. If trees are growing in a lawn or ornamental garden area, however, the heavy applications of fertilizer required for the mature trees would probably kill the grass and other small plants if it were broadcast. So you should place it in holes made with a crowbar at 2' intervals throughout the root zone.

Nuts are ready for harvesting when the husks loose their bright green color and open at the tips. The easiest system of harvesting is to leave the nuts on the tree until they cure and fall naturally. The alternative is to knock them from the tree with light bamboo poles. They should be allowed to dry thoroughly before they are placed in sacks.

If you buy a property with an old pecan tree that does not produce well, you can probably persuade it to mend its ways by pruning out the dead, damaged, and unnecessary limbs; clearing the ground underneath and applying a heavy dose of fertilizer; and watering well. If Spanish moss infests the tree, it should be removed by spraying with copper sulfate. Don't expect an immediate hugh crop of nuts, however: you will probably have to continue this treatment for a couple of years.

Australian Nutgrower 20:36-38 (2006)

A History of Phytophthora cinnamomi in the United States.
Sandra L. Anagnostakis
The Connecticut Agricultural Experiment Station, New Haven, CT 06504
Sandra.Anagnostakis@ct.gov


Whenever a new imported pest or pathogen starts to cause problems, it is useful to remember that this is not the first time this has happened. Chestnut trees were here when the first European settlers arrived, and were generally taken for granted. When they started dying in the southern United States many reasons were presented, from drought to insect predation. The money was in the North, so little was done to find out what the problem was. Human beings have been moving pests and pathogens around the world as long as they have been traveling, and the identification of Phytophthoras as serious pathogens has happened fairly recently. The Connecticut Agricultural Experiment Station has an extraordinary collection of unpublished papers, letters, and photographs that give us accounts of early work on chestnut, and these, with later published papers, give us an account of the disaster of Ink Disease. This disease is still important because several groups are planning to introduce hybrid chestnut trees into the forests of eastern North America.

We now know that Phytophthora cinnamomi causes Ink Disease in chestnut, and that it is an imported pathogen that probably came into the southern United States before 1824. It is very interesting that this pathogen shares two disparate hosts (Castanea and Eucalyptus) with another notorious pathogen, the fungus responsible for Chestnut Blight Disease.

Ink disease was reported on chestnuts, walnuts and cork oaks in Portugal in 1838, and in 1904 Prunet said that:
"The Black Foot Disease of Chestnuts.[is].of all the diseases the most to be feared."
When did we recognize it, and how did it get to the United States?

When Chestnut Blight Disease started killing the chestnuts in the northern and coastal United States, people paid attention. Money was appropriated and surveys were undertaken to track the presence of the pathogen. The darkened area on the map (figure 1) is the native range of American chestnut (Castanea dentata) in the United States. In 1911, Caroline Rumbold quoted an 1856 paper by Hilgard, who had said that chestnuts in NE Mississippi were dead and dying. In 1912, George P. Clinton, from The Connecticut Agricultural Experiment Station said:
"It is well known that in times past the chestnut trees in this country have suffered severely in certain districts, particularly in the south, in some cases being practically exterminated, so that their range is now considerably lessened from what it was originally. Strangely enough, no one has surely accounted for any of these devastations."

Clinton was convinced that Chestnut Blight Disease was not caused by an imported pathogen, but was a secondary infection that came in because the trees were weakened by drought and general environmental causes. Clinton said that blight had either always been here, or had been here for a long time without exterminating chestnuts, and he started collecting references to previous reports of problems with chestnuts. His files include a quote from Asa Gray (1859) that the chestnuts were dying all over the mountains in the Southern U.S. In 1912, Hopkins reported on his surveys in the south, and quoted Mr. Jones of Riceboro, Georgia:
"in 1823 a great fall of rain occurred and late 1824 was also very rainy, in 1825 many chinquapin trees died and continue to do so up to 1845, if the disease is not stopped, trees will be exterminated" [chinquapins are another native species of Castanea in the United States].
This was followed by a press release in 1912 from the Secretary of Agriculture which says
"In some sections of the South where more than fifty years ago the chestnut trees were abundant, very few are present today ... in the Appalachians there is a widespread death of both chestnut and chinquapin."
P. L. Buttrick (1913) was concerned that for many years the chestnut trees throughout portions of North Carolina had been dying. He thought that some of the problem was due to recurring fires (figure 2) throughout the area and to heavy logging throughout state (figure 3) but found no other clear cause.

By 1932, people realized that a disease organism was responsible for this decline of chestnuts and chinquapins and Margaret Milburn and Flippo Gravatt reported a Phytophthora root disease on chestnuts that resembled Ink Disease caused by P. cambivora in Europe. They found that this was a serious pathogen on Allegheny chinquapin (C. pumila), and American and European chestnut (C. sativa), but was not serious on Japanese (C. crenata) or Chinese (C. mollissima) chestnut, dwarf Chinese chestnut (C. seguinii), or Chinese chinquapin (C. henryi).

Bowen S. Crandall (1936) first described a Phytophthora root and collar rot of pine in Pennsylvania, and in 1938 he reported finding this pathogen on pines in Maryland, on pines and several hardwoods in Virginia, and in Tennessee, Arkansas, Oklahoma, Louisiana, Georgia, and South Carolina on chestnuts and chinquapins (figure 4). Crandall then teamed up with the two previous Ink Disease researchers and in 1945 they published evidence that the pathogen was actually P. cinnamomi, and not P. cambivora (figure 5). They mapped the distribution of the pathogen over a wide area (figure 6). In 1950, Crandall noted that cork oak trees from Portugal had been extensively introduced into the United States to exactly the areas where P. cinnamomi became established: the southern U.S. and California.

In 2001, I gave American chestnuts to Dr. S. Brosi at the University of Kentucky for a large planting in the woods. In her thesis she said:
"Infection by the introduced pathogen Phytophthora cinnamomi caused high mid-season mortality at three of the four planting sites Mortality ranged from 22-74% across the sites."
This is a graphic illustration of the problem that is still very much with us. Even though the pathogen does not usually survive the winters north of southern Pennsylvania and New Jersey, we must clearly be concerned about resistance to Ink Disease in any trees that we plant in the eastern forests.

The Connecticut Agricultural Experiment Station, the American Chestnut Cooperators, and the American Chestnut Foundation have chestnut breeding projects and are planning to introduce timber chestnut trees into the forests of the eastern U.S. Selection for progeny with good resistance to Chestnut Blight Disease is progressing rapidly. Dr. J. Frampton and M. Bowles at North Carolina State University have tested chestnut progeny for resistance to Ink Disease. If they are successful in their efforts to understand the inheritance of the resistance to Phytophthora found in many Asian chestnuts, we will be able to integrate their information with that of other breeding programs. Understanding the history of Ink Disease of chestnuts and chinquapins in the United States can help us plan better for the future.

References

1. Buttrick, P. L. 1913. The recession of the chestnut from certain sections of North Carolina. 57pp + 9 pages with illustrations, unpublished report from the Office of Forest Pathology, U.S. Bureau of Plant Industry.

2. Clinton, G. P. 1912. Previous chestnut troubles p407-413 IN: Report of the Station Botanist, 1911, 1912. part 5 of the Annual Report of 1912 of The Connecticut Agricultural Experiment Station, New Haven.

3. Crandall, B. S. 1936. Root disease of some conifers and hardwoods caused by Phytophthora cambivora (P. cinnamomi). Plant Disease Reporter 20:202-204.

4. Crandall, B. S. 1950. The distribution and significance of the chestnut root rot Phytophthoras, P. cinnamomi and P. cambivora. Plant Disease Reporter 34:194-196.

5. Crandall, B. S. and Hartley, C. 1938. Phytophthora cactorum associated with seedling diseases in forest nurseries. Phytopathology 28:358-360.

6. Crandall, G. S., Gravatt, G. F., and Ryan, M. M. 1945. Root disease of Castanea species and some coniferous and broadleaf nursery stocks, caused by Phytophthora cinnamomi. Phytopathology 35:162-180.

7. Gray, A. 1859. Memoirs of the New York Academy volume 6 part 1

8. Hopkins, A. D. 1912. The relation of insects to the chestnut blight disease. 6pp. Bureau of Entomology, U.S. Department of Agriculture, unpublished report.

9. Milburn, M. and Gravatt, G. F. 1932. Preliminary note on a Phytophthora root disease of chestnut. Phytopathology 22:977-978.

10. Prunet, A. 1904. Le reconstitution des Chataigneries. Bul. Mensuel de L'Office de Reseignements Agricoles 3:536-541.

11. Rumbold, C. 1911. A new record of a chestnut tree disease in Mississippi. Science 34:917.