Organic Slot farming: a new approach to growing farming and gardening
We chose to use the farming season of 2011 as a year to experiment and find the best method for creating and maintaining a slot farm. Every variety of seed we planted in the slot farm we also planted in a farm which was tilled and both farms received water as needed. This allowed us to compare the growth of our slot farm plants with the growth of plants grown using a traditional farming method. For our purposes we refer to the traditionally prepared farm as “traditional farm.” The traditional farm ground has been farmed for several consecutive years while the slot farm ground has never been farmed, therefore the traditional farm soil may have a higher nutrient content than the slot farm soil.
We photographically documented weekly growth and the various changes through which the project went. We tracked our water usage, daily temperatures, and rainfall in a separate data sheet.
We planted carrots, cucumbers, squash, radishes, a mesclun mix, and lettuce.
First, we prepared our slot farm ground by mowing the grass of the area in which we created our slots. Our first planting of the slot farm occurred on June 11, 2011. We created two slot rows with the sidewalk edger. The first row we sowed with carrot seeds and the second row we sowed with cucumber seeds. We watered both rows after sowing. On June 18, 2011, a week after we planted in the slot farm, we planted cucumbers and carrots in raised beds in the traditional farm.
On June 20, 2011, approximately nine days after planting slot row 1 and 2 we saw the first germination of our cucumber seeds and a couple days after that took our first growth pictures measuring the plants about approximately a half inch to one inch. On June 24, 2011, approximately six days after planting in the traditional farm we saw the first germination of cucumbers in that farm and measured the growth of those plants at approximately a half-inch. On June 26, 2011 we mowed in between the slot rows for the first time as a means of grass suppression. We mowed eight subsequent times through the project. On June 26, 2011 we also noticed the first germination of carrots in both farms, although in the following days only two seed in the traditional farm germinated and one seed in the slot farm germinated.
In the beginning days of July we noticed that the cucumbers in the traditional farm were more robust and fuller than the cucumbers in the slot farm. We formed a hypothesis that even after the mowing, the grass around the cucumber slot row was suppressing the growth of the cucumber roots. Grass growing too closely to the slot row plants became a recurring issue and we used several methods to try to control the growth of the grass. The first method we tried was laying wooden boards around the slot edge to suppress the grass directly around the slot. In the following week, we began to notice the vertical growth of the cucumbers in the traditional farm was beginning to overcome the vertical growth of the cucumbers in the slot farm. We implemented a technique we nicknamed “edging” in which we used a shovel to scrape the grass back from the slot and then replaced the boards around the newly cleared slots. A few days later we noticed the growth of the slot farm cucumbers was still stifled, so we applied a third method we nicknamed “hand pulling”, which we hoped would provide better root access to rain and sunlight.
We hand pulled the grass around the slot and cleared approximately 4 inches on each side of the slot and then laid the wooden boards back down. At the same time we created a new slot row, slot row 3 and in an effort to avoid having to clear the grass from around the slot when the plants are growing we edged the slot with a shovel before planting. However, when we began pre-edging the slot became obscured, so we stopped edging and we finished clearing around the row by hand pulling the rest of the grass. On July 9, 2011 we planted summer squash in slot row 3 and in the traditional farm. We preemptively placed wooden boards around the first half of slot row 3 to keep the grass we pulled from growing back quickly. We ran out of wooden boards and a few days later finished covering around the last half of slot row 3 with strips of black plastic sheeting, hoping it would have the same effect of stifling the growth of the grass as the wooden boards. (It should be noted that the black plastic sheeting we used was expensive and cost-prohibitive to the project and therefore we knew it was always only a temporary solution.)
On July 18, 2011 the summer squash in the slot farm and in the traditional farm germinated, approximately nine days after planting. A short time later we noticed the wooden boards had become infested with insects so we implemented our fourth method of grass suppression and decided to use straw on the slot rows instead of wooden boards. We removed the board and lay straw where the boards had been and in between the plants. At the end of July the squash at the end of slot row 3 with the black plastic sheeting was smaller than the squash that had straw. We believe the squash with the black plastic were stifled by the sun because of greater heat absorption. We pulled up the black sheeting around the end of slot row 3 and put straw in its place.
After switching to straw the slot farm cucumbers became more robust and we saw the first flower on July 23, 2011. However, the extreme heat in July and August also stunted the growth of the plants and it was not until the beginning of September that they began to fruit and we were able to harvest our first cucumbers on September 14th. The traditional farm cucumbers flowered in on July 11th, but were also affected by the heat and we noticed fruit on August 6th. We harvested our first traditional farm cucumbers on August 30th. Squash in the slot farm grew better than the cucumber in the slot farm, but never reached the size of the squash in the traditional farm. I believe the slot farm squash grew better because in our care for it we used a more fine-tuned process of mowing, hand-pulling, and laying the straw. The slot farm squash flowered on August 13th and began to fruit on August 20th. We harvested our first slot farm squash on September 6th. The traditional farm squash flowered on August 6th and began to fruit on August 13th. We began to harvest the traditional farm squash on August 22nd.
In September, we discovered the presence of cucumber beetles and squash bugs on slot farm and traditional farm plants. We invested in an organic insecticide and applied it to the cucumber and squash plants in both farms, but the squash was already dying from a vine borer infestation and the cucumber beetles had affected the cucumber plants. While the slot farm cucumbers would have continued to produce if not infested, I believe the slot farm squash would have not only continued to produce, but become the best producer of the slot farm vegetables, if not infested.
Unfortunately, with all the methods we tried and continuous mowing, the growth of the slot farm cucumbers never did catch up to the growth of the traditional farm cucumbers and both were severely affected by the July-August heat wave.
The squash in both farms was also affected by the heat wave, but unlike the cucumbers, the squash did not have to rebound from the heat and basically restart its plant cycle. I believe this is why it took less time for the squash to grow to a harvestable size. Even though the growth times of the slot farm squash to the growth times of the traditional farm squash was not severely outpaced as the growth of the slot farm cucumbers to the traditional farm cucumbers, the slot farm squash did not grow as quickly and the fruit did not mature as fast as the traditional farm squash. After all the techniques we implemented, we came to reason that grass suppression wasn’t the only issue in growing slot row plants. We believe because the traditional farm was tilled the plants in that farm has better root access to water and nutrients in the soil and therefore grew faster, fuller and matured earlier than the slot farm plants.
To fully test this theory we created slot row 4, 5 and 6 and planted radishes (4), a mesclun mix (5) and lettuce (6) on September 3, 2011. We relied on rainfall for our water source and only sparingly watered the radishes, mesclun mix and lettuce in both farms and only in equal amounts.
We saw the first germination of both farms plants on September 7, 2011. The germination of the traditional farm radishes, mesclun mix, and lettuce was more abundant than the slot farm radishes, mesclun mix, and lettuce and as I anticipated the traditional farm crops growth outpaced the slot farm growth even more than in the previous June and July plantings. In fact, the slot farm produced so little when rationed of water that I firmly believe that the compactness of the soil in the slot farm played as great a role if not greater in the stymied growth of all the slot farm plants. We stopped tracking the growth of these plants after the first week of October; the slot farm germination rate was small and the growth rate was slow when compared with the traditional farm germination and growth rate, which seemed unaffected by the lack of additional water, and was able to produce marketable-sized vegetables.
Water Added (June)
Slot Farm Traditional Farm
Cucumber 2 gallons 2 gallons
Carrot 2 gallons 2 gallons
Water Added (July)
Slot Farm Traditional Farm
Cucumber 43 gallons 36 gallons
Squash 31 gallons 31 gallons
Water Added (August)
Slot Farm Traditional Farm
Cucumber 23 gallons 22 gallons
Squash 24 gallons 22 gallons
Water Added (September)
Slot Farm Traditional Farm
Cucumber 11 gallons 6 gallons
Squash 13 gallons 6 gallons
Radish 6 gallons 6 gallons
Mesclun Mix 6 gallons 6 gallons
Lettuce 6 gallons 6 gallons
Water Added (October)
Slot Farm Traditional Farm
Radish 4 gallons 4 gallons
Mesclun Mix 4 gallons 4 gallons
Lettuce 4 gallons 4 gallons
June Slot Farm 4.77
June Traditional Farm 1.3
July Slot Farm 17.64
July Traditional Farm 3.05
August Slot Farm 2.96
August Traditional Farm 1.66
September Slot Farm 10.24
September Traditional Farm 2.17
October Slot Farm .5
October Traditional Farm .5
*Traditional farm labor does include tilling time.
The lack of germination of the carrots when compared with almost all the cucumber seeds in both farms germinating led us to believe that the carrots must have been mis-planted (although we followed the instructions on the packet). We decided to try planting carrots again next year.
The time it takes seed to germinate for all the plants in the slot farm is comparable with germination time of the plants in the traditional farm, however the rate at which the seeds germinate varies and the growth rate and fullness of the traditional farm plants outpaces the growth rate and fullness of the slot farm plants. Part of the problem is the tendency of the grass to suppress the growth of the plant in the slot farm and through trial and error we realized that simply mowing the grass around the slots was not enough. To tackle this problem we implemented a variety of techniques which did help to spur the growth of the slot farm plants, and a combination of the techniques, hand-pulling the grass around the slot and applying straw with regular mowing did help the growth of our slot plants. However these techniques can be laborious and our total labor hours were considerably more in the slot farm than in the traditional farm. For this project to be viable, we have to minimize the amount of labor used as much as possible. After examining the differences in the slot farm and the traditional farm we believe we have found the answer and solution to the growth and labor problems.
We concluded that while the slot method does work, it is inhibited by the compactness of the soil in which we sow our seed. In traditional farming the soil is tilled to break up the firmness of the ground and allow the plant root better access to water and nutrients in the soils. By not tilling the ground of the slot farm, the root system struggled to find the appropriate nutrients that would maximize its growth. Concurrently the narrowness of the slot allowed the grass to grow too closely around the plant root in the crucial first stages of plant growth. The solution can be found by adjusting the angle of the sidewalk edger. By bringing the blade up to a forty-five degree angle we will create an angled cut in the ground. Then we will make another cut parallel to the length of the first cut, approximately five inches apart. By removing the dirt that is in between the two cuts, we will create a V-shaped ditch in the ground. We will then sow the seeds in the row and replace the dirt, filling back in the V-shaped ditch we created. As the seeds germinate and grow, the plant root system will have a wider area in which to form and grow out. The 5 inch gap between the parallel cuts will allow the seeds to germinate and grow without the encroachment of surrounding grass. We will continue to mow and when we notice the first growth of the plant, we will apply straw. We will call this new method the “angled-slot” method.
[Editor's Note: To see the drawing, open the PDF file of Slot method comparison.]
(The drawing on the left is the current slot method; the drawing on the right is the future angled slot method.) Notice how the V-Shaped ditch in the angled slot method allows for greater root movement in the first critical stages of plant growth.
Straight neck Squash (Traditional Farm): 4.74 lb.
Crookneck Squash (Traditional Farm): 4.32 lb.
Cucumber (Traditional Farm): 9.62 lb.
Crookneck Squash (Slot Farm): .15 lb.
Cucumber (Slot Farm): .37 lb.
Time Planting to Harvest:
Slot farm Cucumber: 95 days
Traditional Farm Cucumber: 73 days
Slot Farm Squash: 60 days
Traditional Farm Squash: 45 days
Slot Farm Radish, Mesclun Mix and Lettuce: never reached market size
Traditional Farm Radish, Mesclun Mix and Lettuce: 59 days
WORK PLAN FOR 2012
During the next season we will have access to manure that will encourage the growth of the slot farm. We plan to plant a full quarter acre using the new angled slot farm technique next season. We will continue to compare the growth of the slot farm with the growth of the traditional farm for the first few rows we plant using the angled slot method. It is my belief that using the angled slot method, we will see better growth in the slot farm and the amount of labor and water we used this past season will decrease.
Next year I would also like to test one of my theories that crops that grow vertically rather than horizontally, onions (vertical growth) vs. cucumbers (horizontal growth) will fare better in terms of maintaining grass suppression around the slot because their vertical growth allows for easier mowing and application of straw. I was able to begin testing this theory with slot rows 4, 5, and 6; however with the lack of growth in the plants due to the water constraints we placed upon them, we were not able to fully test this. The angled slot method will hopefully mitigate the water constraints and we will be able to test this theory next year.
We had a steady supply of volunteers this growing season. One of the volunteers decided to try different ways of creating a slot on his property. He created his slot in soil without grass and found that the lack of grass kept the slot from maintaining its shape. Therefore, I believe you cannot create a slot farm without grass in which to create the slot. He also thought cardboard would be a suitable replacement for straw as a way of managing the weed and grass growth. He tried two different types of sidewalk edger and found that an edger with two wheels works better for creating slots than an edger with one wheel (the one with one wheel wasn’t as stable).
Other volunteers expressed interest in the project and even considered trying it out themselves; however none have currently relayed news back about their endeavors.
On September 2, 2011 we invited Cathy Bylinowski from Cultivate Kansas City (formerly known as the Kansas City Center for Urban Agriculture) for a taped tour of the slot farm. She offered valuable input on how to make the project work better. She noticed the presence of the cucumber beetles and squash bugs and offered her input on how to eradicate them. She also agreed with our use of straw and suggested we use even more on the rows and in between the plants and reapply it more frequently. We invited her to come back to our slot farm next year with the farmers she works with to tour the farm and show them how to plant using the slot method.
We will also share information about our project at an upcoming business seminar at the main branch of the Kansas City, Kansas Public Library. As the guest speaker of the seminar I will talk about urban farming and will specifically highlight how I believe our project can make urban farming more accessible to people who are looking to begin a farming or gardening effort.
Additionally, next year we will open the slot farm up for tours for our local growers. We will fine tune our procedure and prepare out slot farm manual mid-growing season so it will be ready by late-season for hand-outs on the tours.
- Slot Methods Comparison drawings
- Photographic Log of slot farm measurements compared to traditional farm measurements