Planting Urban Nut GrovesBy William Watt, Nepean
This article describes how I plant nut trees on public property in built up areas. I have been doing this for six years. It all is done for free within walking and cycling distance of my suburban home.
In 2004 I brought home 60 oak and walnut seedlings left over from a volunteer tree planting, gave 4 away, and planted 56 on city property along Nepean Creek near where I live and where I took my daily walks, rather than let them die. I sent an email message to my city councillor to let him know what I did. The creek emerges from storm drains behind a municipal arena and is fed by more storm drains before emptying into the river about 1/2 mile away. Back in 2000 the city had brought in heavy equipment and scooped out storm water settlement ponds along the course of the creek, lay down the paved path, and planted trees, none of them walnuts or butternuts. Some of the trees were planted along a paved recreation path as shade trees. The rest were scattered along the creek in open, sunny places. Since then I have gathered walnuts, butternuts, and acorns on public land and planted them along the creek, along the Rideau river, and at a park made from an old limestone quarry, all close to my house.
Walnuts, acorns, and butternuts can be gathered on public land. Acorns should be gathered the end of August. By then they are mature enough to germinate. Walnuts and butternuts should be gathered in the middle of October. A strong wind will put so many on the ground that they can be gathered before the squirrels get them. I gather walnuts from two trees which produce large nuts. One of the walnuts is still young and began producing at the early age of 8 years. These are traits to propagate. Acorns are gathered from long-living native white oak trees. Some walnuts and acorns are gathered from other trees for hardiness in cross pollination. Butternuts are gathered from trees which show no signs of being infected with the canker which is destroying the trees.
Walnuts and butternuts grow from seed in the field but acorns are a challenge. Therefore acorns are packed in dirt and stored in a cool place over the winter. In spring the containers are left in the sun by a window. After a couple of weeks most have started to grow. The containers are opened. When the seedlings are 3-4 inches high they are transplanted. Last fall I packed acorns individually in used garden plant containers to make transplanting easier. The filled containers were sealed in plastic bags for the winter. Most of the seedlings are transplanted to the creek but a few have been planted in a small nursery in my back yard to grow stronger before transplanting in a year or two.
Trees must be planted where they are not likely to be in the way or to be disturbed over their long lifetime. Public land is ideal. Natural areas along water courses, ravines, and wetlands are not likely to be disturbed by real estate development. Trees planted in rough areas will not be in the way of public employees cutting grass.
Trees should not be planted near overhead or underground utilities. A mature tree can cost the public a great deal of money to trim around utility lines over it's long lifetime. Trees should not be planted near property boundaries or man made structures. Nut trees should not be planted so close to roads, paths, or parking that the nuts and leaves litter the surface.
Otherwise they should be planted in the usual recommended sunny places with deep well-drained soil. I can only tell if they've been planted in a good spot after the fact by how fast they grow compared to the others.
Nuts I planted on a bridge embankment are stunted. Although it's a sunny location, the fill beneath the sod seems to be lacking in nutrients.
Stakes and wraps let people know the trees are plantings, discouraging damage, although I had stakes pulled out. White plastic wraps make the trees visible, an advantage when it comes to finding seedlings in tall grass for monitoring and maintenance. White plastic wraps stick to walnut and butternut bark so they have to be loosened at least once a year. They have to be removed when the trunk is about 3 inches in diameter or they will strangle the tree. When the city planted trees in 2000 a cache of plastic wraps was abandoned under a hedge. I found them later, cleaned them up, and have been using them for free.
One foot high wire cages protect trees from small rodents. There have not been any deer at the creek since a real estate developer cut down a small wood. Chicken wire keeps out groundhogs and rabbits who eat leaves but not mice, voles, and chipmunks who eat bark. Adding a strip of window screen to the bottom of the cage keeps out the smaller rodents. Cages made of 1/2 inch wire mesh (hardware cloth) protect against all rodents. Cages must be removed before the trunk becomes large enough for them to restrict growth. So long as the root is good a tree can grow new leaves but is more likely to die from loss of bark. I found chicken wire at a garage sale. Later I got a roll of hardware cloth free from the city under a beautification program. The rolls are 3 feet wide. Cutting a 1 foot strip makes a cylindrical cage 1 foot high and 1 foot across. I cut stakes from buckthorn or similar invasive shrubs on site and fasten the cages to them with wire or plastic cable ties.
One square foot of sod was lifted to plant each of the seedlings the first year. Groundhogs took advantage of two to make entrances to burrows, killing the seedlings. The holes were blocked with stone and cages installed before seeds were planted to replace the seedlings.
One foot high wire cages do not protect trees in winter when rodents, including beaver and muskrat, can walk on the snow. The city used 3 foot high tough plastic to protect trees planted near the water but that was not enough. I put 5 foot cages around nut 2 trees planted close to the water. Fortunately beaver prefer the wood of softer trees like willow and poplar. I have not tried planting willow or poplar to protect nut trees.
Ants seem to be attracted to oak trees, perhaps because they are both acidic. I improved the progress of 3 stunted oaks by digging up ant nests and moving them. Two other oaks with ant nests died.
Now small oak transplants are protected with clear plastic soft drink containers with the tops and bottoms cut off. These cylinders are staked around the seedlings with pieces of coat hanger wire.
Tree seedlings should be watered during dry spells for 3-4 years until the roots are deep enough to find water. I draw water from the creek in buckets and give each tree half a bucket. I have not watered the walnuts at the quarry and stopped watering the trees along the river due to distance.
Long grass around the trees can be cut until the trees are taller than the grass. That's to give them air and light and to make them more visible. Trees were damaged by city weed cutting the first year until they were made more visible. It also discourages ground hogs who seem not to like being in the open. This year I saw a coyote at the creek and no groundhogs or rabbits. I use manual grass clippers from home and a "weed whacker", a sort of golf club scythe I found at a garage sale. I've also used a pocket knife and a curved linoleum knife. They all work.
Broken branches should be pruned close to the trunk. I carry a pocket knife so when I walk along the creek I can prune any I find. Shade trees should be pruned of their lower branches and to thin out the interior branches. I wait until the tree is at least 6 feet tall and well established to begin pruning with a pruning saw. The scars are patched with roofing tar.
It's possible to keep records if desired, as detailed as one wants. I made a rough map and marked all the first year trees on it so I wouldn't forget any or where they were. After a couple of years I began measuring their height each fall. Now about a dozen are over 10 feet tall and too big to measure. I sporadically count the number and kind of nuts I plant. Each fall I take inventory of the trees along the creek. After taking inventory I write a report of what I've done and how the trees are progressing and send it to my city councillor with a copy to the city tree bureaucrats.
In 2010 there were almost 100 nut trees growing along the creek, over 50 along the river, and 3 at the quarry. I do it all on foot or by bicycle. I enjoy the satisfaction of watching the trees grow as I walk and cycle for recreation. I'm pleased to leave something for the people who come after.