The Nuttery : Volume 8 Number 2 March 1989

In this Issue...

The Annual General Meeting

The Ottawa Area Chapter of the Society of Ontario Nut Growers (SONG) will hold its 1988/89 AGM at the Interpretive Center, Baxter Conservation Area on Saturday March 18, 1989. Registration begins at 9:30 AM. The Business Meeting begins at 10:00 AM. Technical Sessions start at 1:00 PM. Lunch from noon to 1:00 PM. Please bring a lunch. Coffee will be available.

The Chapter's AGM has traditionally been held in the Interpretive Center at the Rideau Valley Conservation Authority (RVCA) Baxter Conservation Area. The Chapter's major project, the Baxter Nut Grove, is there, and mid-March is a good time to inspect the grove to see how well it has weathered the winter.

The highlight for this year's AGM will be the special guest speaker, Sherwood Miller. Mr. Miller is the superintendent of the Smithfield Experimental Farm mentioned in the Chapter's latest book "A Nut Growers Manual for Eastern Ontario". The farm, near Trenton, specialises in experimental nut growing, so is probably our best source of new knowledge for the eastern Ontario region. The farm is currently pressing on with a variety of species, specially the Japanese Heartnut, the English Walnut, the northern pecan and Hazelberts. These nut bearing trees and shrubs are all referenced in the Growers Manual as good candidates for this region. It is the Japanese Heartnut, however, that probably is the best candidate of all.

The Manual, and the Chapter's cookbook, will both be on sale at the meeting. If you have seeds to exchange, bring them along. Bring interested friends, neighbours, and relatives. All are welcome. See you at the AGM!

New Ideas in Tree Care

Last fall I attended a half day course at Algonquin College called "New Ideas in Tree Care. It cost $25. Perhaps most of you already know the stuff I am going to tell you about, but I felt it was worth the money and time. There were only about 10 people at the course, and with just one short coffee break we did not get talking to each other except to see who had change for the coffee machine, but I gathered that two men were in the tree farm business, supplying new homes with trees.

The man who spoke was quite young and I was surprised to hear that he was in charge of trees at the Dominion Experimental Farm in Ottawa, and has been there for at least three years. His name is Marcel Beauchamp. Since he arrived, there has been no spraying program using insecticides. But I will tell more of that later.

The course started with a lesson in the anatomy of a tree, which for me was a review of some Grade 13 knowledge. We started at the heartwood and worked through the sapwood and cambium to the bark - discussing the function of each. He described briefly how it might be possible to save a tree after girdling by mice, but went on to add that you should read the method in a book and do the job very carefully - bridging the gap with year old twigs and keeping your fingers crossed.

The root system was next - and we know that in sandy soil the roots go deeply searching for food, but in clay soils they are usually shallow. Large woody roots anchor the tree, while the fine rootlets absorb water, minerals and oxygen for tree growth. These rootlets are found starting at the crown's drip line, out further another 1/3 of the distance from the trunk to the drip line. Any fertilizing must be done at these rootlets, not by the trunk. For the tree to grow, the soil must remain open and friable to allow oxygen to penetrate to the rootlets.

Damage to the roots - for instance, by excavating a house foundation that cuts off some roots - will be reflected in a proportionate loss of the tree's crown. For example, if half the roots are lost, half the crown will be subsequently lost. If you are transplanting and have cut off many of the feeder roots, these must grow back before the crown will show any new growth (this could take two years). Trees for transplanting that come with the roots potted, bagged or wired may be pot bound. The binding must be removed and the roots spread out or the tree cannot fully recover: the new root growth may not be able to escape the compaction, so a healthy root system may never develop.

Each kind of tree is finicky about what soils it likes or dislikes. In most soils there is a fungus which can grow on the root tips, and which can live in a symbiotic relationship to the root feeder system. In other words, it helps the roots absorb raw material more easily. The fungus is called mycorrhiza. In the city it is not as plentiful as in woodlots, and for this reason, the top growth of city trees is less.

In planting, you must plan ahead - not just because you would like the look of a certain shade tree in front of your house - but taking into consideration the size it will grow, the amount of light it will receive, the moisture conditions and the actual health of the plant you select.

Mr. Beauchamp emphasised that you should dig a BIG hole when you transplant so you do not crowd the roots. If the side of the hole is glazed by the shovel, break up that earth to help the roots penetrate the glaze. When filling the hole, do not use peat moss. In fact do not add anything. Peat moss sucks the water out of the ground, making it unavailable to the rootlets. And if you amend your soil with fertilizer, the roots like that so much they will not grow out in search of nutrients. It makes them lazy. Putting plastic over the soil to keep it moist is not a good idea as it prevents oxygen from getting to the roots. The best growth is to be had by putting a mulch over the soil and he recommended a 1" layer of grass clippings with 3" of chain saw shavings on top. This mulch prevents competition from grasses which would restrict tree root growth. In fact, as much as 68% loss of root growth! Putting sod back around your tree on your front lawn is also bad because it will form a quite impenetrable layer, preventing water and oxygen from getting to the tree roots. Two growing seasons without grass for 30" around the base are needed to achieve good tree growth. Mulches such as straw or hay which is two years old, wood chips and grass clippings can be of value. Mulches are better placed at the tree drip line and not around the trunk. In fact it is better to make your mulches look like a saucer - higher at the rim. If you want to fertilize, use blood meal not bone meal. If you really must use inorganic fertilizer, place the high nitrogen fertilizer on top of the mulch - and make sure it is the slow release kind. Lastly, do not press down the earth you used to fill the hole, and break up clumps of soil.

When the tree starts to leaf out, do not prune it at all. The leaves are all needed for food production and root growth: it has been found that the buds send a stimulant to the roots to start production just before they bud out. Never stake a tree. The trunk will develop into a stronger support system if it is left to blow in the wind for the season. If you stake it, it will not develop strength. If you plant the tree so that it is shaded perpetually on one side (for example next to the house), the shade causes the cells to overgrow, and push the tree to one side, away from the shade.

Prune the tree in the spring only if it is not a bleeder. Otherwise, prune it in the summer. Never prune in the fall. Leave a small stub of branch when you prune. This is the branch collar, special tissue that grows over the wound. Select the scaffold branches early in the tree's life, and if the tree grows forked, remove one to restore a single main leader. Black walnut has a tendency to grow forks. Simply bring the tops of the two forks together at the tops so that one is straighter and thus taller than the other, tie them together temporarily, then when the taller one has adopted this new angle, cut off the other fork. This will restore a single main leader pointing more or less straight up. If pruning is important to you, read the Grounds Maintenance Magazine pp.19-26 available at the Sir John Carling Building Library. And, while I am mentioning sources, the Journal of Arboriculture can be found there, along with information from the US Tree Service. Mr. Beauchamp also recommended a book called Arboriculture by Richard Harris - $55 - with new ideas in lots of detail.

There has been a study done on wood chip mulches which proves they increase the horizontal and vertical root growth; it is specially valuable in sandy soil, providing potassium for the soil, and by keeping control of the soil temperature and moisture, increases root growth. Regarding the control of insects, the Farm has stopped using most pesticides - there are no broad spectrum insecticides used. Only natural controls are used - specifically mentioned were Safer's Soap and BT (Bacillus thuringensis).

If defoliation takes place, the effects are determined by the severity, the frequency, the time of year, the weather at the time, the presence of secondary organisms and the tree's vigour. Refoliation produces smaller leaves - which in turn produce less reserve food for next year, so you may see some natural crown thinning the next year. If there has been a 50% loss of leaves, but it has occurred early in the season, the tree will refoliate. The tree uses its food reserves to make the new leaves, so you can see the tree suffering the following year. Also, the new shoots may not be hardy enough to withstand winter kill. The tree becomes less resistant to disease. If the leaves are lost two or three years in succession, the tree will most likely die. Larch appears to be extremely hardy and may survive as much as 11 years of defoliation. The timing of leaf loss produces least damage in early spring as the weather is cool and this in itself slows down leaf production as well as bug activity. Summer defoliation is the worst time and during late summer the trees will not defoliate, so the least damage occurs in the fall.

Continued wet conditions can produce a disease in young leaves called anthracnose. But high temperatures and dryness can scorch the leaves - both resulting in lowered food production. During refoliation, do not fertilize. If you trees are healthy they can withstand the effects of trunk borers and shoestring root rot. Dormant oils are relatively safe to use if you think the trees have a borer problem, but never use Cygon except on birches.

If you have an infestation of caterpillars eating the leaves, nearby trees can actually change the chemical composition of their leaves to make them less palatable to the caterpillars. So trees can actually communicate, and tell their neighbours about imminent problems. If you have sawfly (green yellow caterpillar with black on the head) on your mountain ash or mugho pines you will notice that shadows cause them to arch into an S position on the branch. The eggs are laid on the edges of the leaves. Use Safer's soap on these guys and check over a two week period to see if a second treatment is necessary. Malathion, it has been found, kills the parasites of the pest as well. Thus the pest population can come back with a vengeance. For this ecological reason, Malathion (and other non-specific biocides) should be discontinued.

One other thing Mr. Beauchamp mentioned was that it is wrong to assume that roots go as deeply as the crown grows above. Roots mostly grow out. Only a single tap root goes on down. The rootlets are generally in the top 10" of soil around the drip line of the tree and that is why grasses affect root growth so much. The effect of construction on root loss shows up later in the crown. The deeper the earth is dug away, the more damage to the tree. Similarly, piling earth on top of the roots can cut off the oxygen supply and thus smother the tree. To counteract this, drill holes on the ground just beyond the drip line to let lots of oxygen into the soil. Compaction reduces the soil pore space as much as 50%. Ideally the porosity should be 80%. And lastly - only young trees can benefit from fertilization. An older tree could be fertilized with ammonium nitrate, but it is not really necessary.

The hardiest known tree today is the ginkgo bilboa because it is resistant seemingly to common air pollution. Insects do not bother it very much. It is the last species of an ancient order of conifers, its leaves found in the fossil record essentially identical to today's ginkgo leaves. The species could be 150 million years old! The seeds are orange coloured and are a great delicacy when roasted. But do not forget that you must have a male and a female tree.

Irene Woolford

A Black Walnut in Ottawa

In 1971, I planted a Black Walnut seedling in the back yard of my home in west-end Ottawa - specifically, 37' north of the house and 6' from the top of a 4' high retaining wall. There are no trees or buildings on the north, east, or west sides to offer any protection. The location is on filled land consisting mostly of clay with some sand and stones, plus a thin layer of top soil.

Ten or twelve years ago, the tree began to bear nuts and it produces a bountiful harvest each year which is greatly appreciated by the squirrels and some birds. In a good year we manage to save a dozen or so nuts for ourselves.

The tree now measures 24" in circumference at the base of the trunk and reaches 40' straight up, despite severe pruning on one side to clear power lines.

Dan S. Slade, Baseline Road, Ottawa

The Siberian Connection

Last year, Agriculture Canada received a request for cooperation from a newly designated nut- tree seed farm near Abakan in southern Krasnoyarsky Krai in Siberia. The farm is approximately 53° north latitude and close to the northwest corner of Outer Mongolia. The operator, Mr. K.I. Koshelev, noting the similarity between his climate and ours, enquired whether we had species of Carya, Juglans, Quercus, Corylus and Fagus that he might grow. He offered to reciprocate with Siberian seed if we were interested.

The Dominion Arboretum (through Trevor Cole, Curator) responded to his letter and asked SONG Ottawa Area Chapter for cooperation. We have reported to him that we can offer black walnut, butternut, bur oak and beaked hazel immediately, and that we would be interested in hardy Persian walnut and Siberian Nut Pine. Mr. Cole sent off this information and we await results.

Alec Jones

The Seed Exchange

Wanted: 50 seeds collected from local Heartnut. Will purchase or trade for Nursery Stock (have a large selection of hardy fruit trees, bushes etc.). Grant Dobson, Connaught Nursery & Gardens, R.R.5, Cobden ON K0J 1K0 (613)646-2386. The nursery is located in Renfrew County, road 11.

Editor's note: Grant and Dorothy Dobson are members of the Ottawa Chapter. They are also official Organic Farmers, registered in the new Ontario Organic Farm Products no.1 1988 published by the Organic Foods Register of the Canadian Organic Growers Inc. The Dobsons are organic growers of hay, apples, strawberries, currants, herbs, asparagus, cucumber and tomatoes.

Provided by ECSONG. Feel free to copy with a credit.