By Michael Leach
One of our readers, Rebecca Stultz, asked about bringing no-till farming practices into the home garden. This was in early March, just as the spring rush burst upon us. Thank you for your patience, Rebecca. We hope this guides you in making yours a more sustainable landscape.
At first, no-till may sound exotic but probably most gardeners use aspects of this approach to agriculture. Do you mulch to reduce watering, weeding and improve the soil? Have you spread sheets of cardboard or layers of newspapers to transform a portion of lawn into a new garden or landscape bed to spare your aching back? That’s part of no-till.
No-till has been out on the farm for years. Time, fuel and soil erosion are reduced simply by skipping traditional plowing. Remains of the old crops serve as mulch that eventually decomposes into organic matter that enhances soil quality. Cover crops are planted to enhance soil nutrition and tilth. This approach requires special seeding devices to minimize soil disturbance that brings fresh weed seeds to the surface where they sprout and cause trouble.
Now to Rebecca’s questions.
When and how should compost and/or fertilizer be added/incorporated in each year’s cycle for no-till?
A professional soil test will show what type soil and its nutrient content, the amount of organic matter and other aspects of your soil so you can tailor amendments precisely.
Some anecdotal information I found shows that Ruth Stout, garden author and contributor to Organic Gardening used no-till for decades. At planting time, she scratched the soil’s surface enough for the seeds to make contact, lightly covered them, and sprinkled cottonseed meal along the “furrow.” Her 8-inch layer of hay (preferably slightly spoiled) continually decomposed and was renewed, so compost, cover crops or other amendments weren’t necessary. She touted thick mulch as a way to eliminate watering, weeding and most other maintenance. That amount of mulch seems excessive but it quickly settles to a 2- to 3-inch mat.
Lee Reich, a national garden writer and no-till fan for 20 years, prepares the planting area by covering it with a 1-inch layer of compost at planting time.
If fall leaves are not tilled or forked in, how thick a layer is practical to leave on the beds and still plant rows of seeds?
Remember the mulch is pulled back at planting time to expose only the soil you want to plant in. You don’t cover the seeds with mulch.
As for handling leaves, personal experience shows that 2-foot layers of sugar maple leaves “stored” overwinter in a vacant bed become a 3- to 4-inch layer by late May. This layer goes to nothing before the next leaf drop. No forking or spading is needed.
Because my leaves are collected with the help of a lawn mower, they mix with grass clippings, that probably speeds decomposition. Even without being chopped and mixed with grass clippings, autumn leaves in the forest all but vanish by mid-summer.
The more mulch the better
“Whatever you use, don’t skimp on mulch,” Barb Flick says in an Oregon State University Extension article. “A heavy layer not only keeps weeds from growing, it also keeps the underlying soil moist, greatly reducing the amount of watering you need in the summer.”
Using a thick mulch over several years adds more organic matter helps soil become like a sponge in absorbing water, says Mike Hogan, Ohio State University Extension educator and professor.
If the recommended 8 to 10 inches of mulch is hard to come by, Flick suggests using sheets of cardboard or layers of newspaper on the ground. This smothers out most weeds and keeps weed seeds from germinating. Cover this with a layer of mulch.
This is what Christine Voise does. In addition to her regular job as geographic information system and accession specialist at Ohio State University’s Chadwick Arboretum, she grows fresh vegetables for restaurants. Thick mulch keeps plants — and gardener — cleaner because there’s no mud to splash onto leaves, fruit or track inside.
Voise only waters the plants after planting and relies on a thick mulch around to get them through. Years of heavy mulching has enriched the soil to that sponge-like quality.
If straw is used as a mulch around plants, in the fall should it be left on the beds under the leaves or put in the compost bin?
Add mulch whenever it’s needed. Whatever the material — leaves, straw, hay, compost, grass clippings — it all eventually decomposes. If there’s still several inches of straw or other mulch on the beds, fewer leaves will be needed to maintain the desired cover depth.
What cover crops work well in suburban garden beds?
There’s plenty to learn about cover crops in an article in the July 8, 2015 edition of Organic Life. Cover crop benefits include suppressing weeds, building productive soil and helping control pests and diseases.
You may not need to use them. A thick mulch also cuts weeding, watering, soil erosion, while improving soil quality after it decomposes.
Personal experience makes me leery of cover crops. The only one I tried was so vigorous it took weeks to kill and delayed planting.
Precautions — Common sense dictates some basic sanitation no matter what approach you use to gardening. Reduce chances of diseases or pesky insects hanging around to attack future vegetable crops by collecting vegetable leaves as they fall off. Remove spent plants for municipal composting collection. If you have a hot compost pile, such debris can be disposed of there because high temperatures kill pathogens.