How to Grow an Orchard in the Heart of a City
Thanks to Rod Kueneman for sharing this local tree story. Rod is founding member of the Sustainable South Osborne Community Co-operative. In addition to establishing gardens across the area, SSOCC has also established a successful orchard, creating a treed oasis on what was once an empty grassy slope along the Churchill Drive dike.
A Tale of the South Osborne Orchard: Learning from Our Mistakes
This the story of the orchard we established on Churchill Drive Dike, an account of the mistakes we made, what we learned, and the changes we continue to make to develop the orchard into a healthy, low maintenance, permaculture food forest.
Fruit trees in a field of quack
Our first orchard was planted on the interior slope of the Dike. The soil is compacted clay and was covered in quack grass. The trees were planted in three rows 20 feet apart, with 20 feet between each tree. The spacing turned out to be correct. The mistakes were just about to begin.
Since it is clay soil, we decided to dig a three-foot hole, two feet deep for each tree, and fill it with 4-way soil mix, assuming that this would give the trees a good start. That was our first mistake. Fruit trees, like all trees, should be planted in resident soil. They actually do better in poorer quality soil (so do grapes). By digging a hole in the clay and filling it with rich water-retaining soil, we were essentially creating a flower pot, which, in a wet season, can retain too much moisture and drown the tree. Just as bad, the tree’s roots can wind up growing in a circle and never develop the branching root system needed to support the weight of a heavy fruit crop.
Fortunately, the slope of our orchard provided enough drainage to avoid the waterlogging problem, but a few of the fruit trees remain unstable, and need to be supported, due to a circular root system.
Once the trees were planted, we then turned our attention to the quack grass. We wanted to remove the grass from around from the trees, so we cut the sod within an eight-foot ring, flipped it over and stacked it like a retaining wall. We filled the ring with more 4-way mix and planted in potatoes, chives, garlic and onions, to repel the fruit-loving deer and produce some food. This was our second mistake. At first, the “guild” plantings seemed to work. Then to our dismay, the flipped quack grass sod now energized by the rich soil, simply re-rooted. In subsequent years we diligently forked out the quack grass roots, but eventually had to abandon that approach to avoid damaging the developing tree roots.
Terracing the trees and building an irrigated food forest
As the trees grew, it also became clear that there was not enough moisture in the soil of the dyke to keep the trees hydrated. Watering by hand with 5-gallon pails worked in the beginning, but as the trees grew, this approach was unsustainable. So we decided that we would remove the sod ring around the trees and group them together in a terrace holding three trees.
By this time, we had begun our journey into permaculture and decided to establish a food forest. This meant planting some berry and other bushes as an understory of food producing plants. Because it would take several years for the trees to grow to a size that would shade the terraces, we also inserted four beds of 4-way mix in each terrace to allow us to grow some annual food crops. We cut the sod, flipped it and left it to die for a five-week period prior to using it to create a border and retaining wall on the downhill side of each terrace. We covered this border with 18” of woodchips to help keep the quack grass in the pathways from coming back into the terraces. Then we installed the irrigation system so that the trees and berry bushes could be watered with hoses from a pump- pressurized irrigation system, which included a 3000-gallon storage tank. We also installed drip irrigation tapes for the annual beds.
The terracing was an improvement, but the quack grass problem persisted. While the beds for annual crop production worked well the first two years, by the third, the quack grass was back. The problem worsened, and by the next season, quack grass was well established again, and we were unable to dig it out without damaging tree roots. We applied flax tow, which helped suppress the quack and retain water. Unfortunately, it also provided shelter and nesting material for voles!
Vole populations exploded throughout Southern Manitoba in 2018 but seemed especially plentiful in the orchard. Over the next two years, the voles killed a dozen apple and cherry trees, by digging under the hardware cloth barriers we had installed around the trunks and chewing through the bark. The arrival of 6 foxes in 2019 helped to radically reduce their numbers, as well as the prairie dog and rabbit populations that can also damage fruit trees. Three years ago we applied SCOOT (a bitter tasting fungus that repels voles, mice, rabbits and deer) on the trunks of the tree with good results. The next fall we removed the wire cages, relied solely on the SCOOT and the trees remained damage-free. This is now an annual practice. We also began applying tanglefoot barriers on the trees because they are now too large to remove the canker worms by hand.
For the past few seasons, we have controlled the quack grass by mowing it and using the weed whacker to keep it from seeding. We have also been battling the invasion of bindweed in a few of the terraces. It is also very difficult to control. The retaining wall we built on the lower side of each terrace turned out to be a big mistake. The quack grass in the flipped sod was not completely dead, even after 5 weeks, and in the following years, it recolonized the wall. The resulting raised border is full of quack grass to a depth of over 12 inches. It has created a very uneven surface and a tripping hazard. It is difficult to scythe the grass because of the unevenness and so weed whacking has been necessary.
The berry bushes planted on the upper edge of the terraces have been slow to grow, largely because they are competing with the quack grass for water and nutrients. The fruit is small and routinely attacked by the Spotted Wing drosophila (fruit fly).
Growing a food forest on a bed of woodchips: the North Orchard and River Garden
When expanding the orchard to the Northeast, we confronted hard gravel filled soil. This material had been added to the back of the clay dyke when there had been hospital construction in the late 1990s. It was impenetrable and we could not dig holes in it to plant trees. So we innovated. There was an ample supply of free woodchips due to the Dutch Elm disease and so we added a four-foot layer of woodchips on the site, dug holes in it, filled them with 4 way mix soil, and planted trees and berry bushes into the soil. The plants were growing in a mound of soil surrounded by woodchips which acted as a porous pot!
We also installed three hugelbeds in this orchard. We began with a layer of dead tree trunks and branches, draped flipped sod (which had been drying for 7 weeks) on top of the wood and covered with 4 way soil mix. This technique was successful in killing the quack grass sod and the beds were very productive for two years. But we made a different mistake this time. The empty spaces between the logs and branches were converted by prairie dogs and voles into housing which grew vegetables on its roof. The explosion of these animals was the end of abundant food production on the raised beds. We have since opened these hugelbeds, filled the spaces with woodchips and recovered with soil. They are now productive again.
The fruit trees grew reasonably well although several of them were killed by voles which ringed the trunk bark at ground level. The berry bushes flourished at this site. They grew quickly; produce large, juicy berries which are free from fruit fly damage which had been a major problem less than 500 feet away. This approach to developing an understory of fruit seems promising. Within 4 years, much of the woodchips have been converted to soil and another 2 feet of woodchips were added to this site last year.
The River Garden site on the river side of the dyke was a restorative undertaking. The location had been disturbed in the 1950s, by the excavation of the clay used to build the dyke and the construction of the pump-house site. Cement from streets and sidewalks had been deposited at the site and, over 50 years, the weeds and quack grass had formed a couple of inches of soil which, along with flood soil deposits made it possible for the growth of a maple tree stand close to the river forest. But the large meadow and the side of the dyke was mostly weed covered cement rubble.
With the experience gained in the north orchard and an even greater supply of woodchips, we negotiated a waterway permit to cover the site in a thick layer of woodchips, to start building soil in a more accelerated way. The 3 – 4 feet layer suppressed and killed the burdock, thistle, and quack grass growing there.
After one year, we excavated holes on the upper side of the dyke down to the original soil base and filled them with 4 way soil mix. We then planted 40 trees in these pots of soil. We also planted 65 berry and nut bushes directly into the soil that had been deposited at the edge of the river forest.
These bushes are doing well. The trees have also been doing well and the woodchips around them will be topped up last year as much of them have been converted into soil by the fungi and bacteria. The rest of the site is now ready to have soil beds inserted into it. By this time we’d learned a lot and decided that it was time to return to the old orchard to renew it.
Developing a polyculture meadow in a food forest
We’d learned a lot about using woodchips help to improve soil biology. We also studied YouTube videos and books by Gabe Brown and Bryan O’Hara on how to rejuvenate soil through the planting of polycultures, the use of no till methods, and the use of solarization.
Armed with that knowledge, we returned to the first orchard and started by removing the lower terrace quack grass walls. We rototilled them then raked out as much quack grass root as possible, Next we put down black tarps for 11 weeks to solarize and kill the quack grass and bindweed. Last August, we planted a cover crop, a polyculture of annual plants using a seed mix call TG Smother (see: https://imperialseed.com/portfolio-items/ccmixtures/ for details).
These annual plants died in the winter leaving a layer of organic plant material and a layer of decaying roots. This spring we’ll plant another polyculture of annual and perennial seed (TG Rejuvenate) to establish an effective plant cover, which will also provide food for the bees, aggregate the soil, improve water penetration and storage, sequester carbon in the soil, and cultivate a robust soil biology (fungi, bacteria, worms, crustaceans, etc.) which can release minerals, and build nitrogen.
Next year we will seed TG Pollinator to increase the food sources for bees and seed plants known to attract beneficial predator insects. Aesthetically, the orchard will be much more appealing and productive. We will be able to scythe the grasses during the year, which will stimulate new growth and fertilize the soil. If we could bring in a petting zoo of sheep to eat it, the neighbourhood children would have a treat!
The existing terraces will remain in place and will be covered with woodchips to help build soil and suppress weeds. We hope to reproduce the successful fruit bush results we are enjoying in the north orchard. We have already begun to plant many more berry and nut bushes to cultivate a more robust understory of perennial plants in the orchard understory.
If we could do it all again, how would we develop an orchard on a field of quack grass?
If we were starting on this same location, given what we know now, here’s what we would do. We would begin by solarizing the future footprint of the orchard with black silage tarps for a minimum of 6 weeks. If time allowed, we would tarp in the fall and leave them in place until the following July.
We would then seed the entire area with TG Smother to start the development of a living cover crop. The following spring, we would plant TG Rejuvenate into the crop residue and get this polyculture cover crop established. We would cut it a couple of times (leaving about 60% of the growth undisturbed) to stimulate root development. That fall, we would plant the fruit trees and berry bushes into this cover crop. We would then lay down a woodchip cover around some of the trees and bushes and leave others surrounded by the poly cover crop. We could then see (in the following years), which strategy worked best to develop and maintain an orchard. The following spring, we would plant TG Pollinator into the existing cover crop to increase plant diversity and provide food for the birds and the bees!
Come visit our orchard! We always happy to talk fruit trees, soil rejuvenation, and helping nature build a healthy robust biome.
Rod Kueneman, VP Programming
Sustainable South Osborne Community Cooperative