No-Till in the Home Garden: Why and How

Most of us have grown up believing that tilling is an essential annual garden task to bury weeds, loosen soil, and create a smooth, clean planting bed. We know now that the benefits are temporary. Tilling buries surface weeds but brings buried seeds to the surface where they can germinate. It loosens the soil temporarily but upsets the soil food web, destroys soil particle aggregation that affects air and water penetration and availability, and releases a lot of carbon into the atmosphere. After a couple of rains, the soil re-compacts and erosion issues return. Finally, unless organic matter (OM) is added to the soil, growers tend to rely on chemical fertilizers, insecticides, and herbicides to feed and protect plants. The combination of runoff and chemicals is a well-documented cause of pollution of surface water and waterways like Chesapeake Bay and is a major cause of pollinator death.

No-Till, when well-managed, has a more positive impact on soil health. It is part of a set of practices that are advocated by The Virginia Soil Coalition (4thesoil.org) that includes:

• Keep the soil covered
• Minimize disturbance
• Maximize living roots in the soil!
• Energize with diversity.

No-till is a central element of this natural soil improvement philosophy. When combined with related regenerative practices, it covers and protects the soil year-round, doesn’t disrupt soil life or structure, reduces compaction, and doesn’t bring weed seeds to the surface. No-Till works with cover cropping, mulching, interplanting and crop rotation to achieve the goals of the 4theSoil movement mentioned above.

So, how can a home gardener convert from tillage to no-till?

Start in the fall

 Going no-till and building healthy soil naturally is a long-term commitment, not an instant fix. It makes sense to start the conversion in the fall when the beds’ growing seasons are completed.

A soil test is a great way to start. If an addition of organic matter (OM) or a pH adjustment is needed, or if serious weeds or roots need to be removed, a single tillage can make sense to speed up the desired soil change.

A winter cover crop is the top choice for soil protection over the winter. Cover crops can be planted from mid-August to mid-October in our area, but as winter gets closer, the choice of cover crop narrows as the time available for it to establish prior to winter, diminishes. Winter-hardy cover crops may go dormant but survive winter and restart growth in the spring. Winter-kill cover crops are killed by winter freezes, and their killed vegetation forms a mulch layer on the garden bed. It can be left in place or composted in spring. Guidance for cover crop selection is offered in the article Improve Vegetable Garden Soil with Cover Crops from the Penn State Extension.

If harvest is too late to establish a cover crop, provide winter soil protection by covering the beds with an organic mulch like straw, or chopped leaves. Extension experts suggest up to 6 inches of mulch to maximize effectiveness. Mulching doesn’t add roots to the soil like cover crops, but it provides soil protection and adds organic matter that will increase soil health over time, making it a good second choice. It also enables early spring planting without having to wait for a winter-hardy cover crop to flower.

Another option, especially for new beds, is sheet mulching. Sheet mulching requires laying out beds, moistening the soil, covering the bed areas with overlapping newspaper or cardboard, and adding 6 or more inches of a mix of organic material (soil, compost, wood chips, straw) and letting it decompose until spring when it can be planted into directly.

The bed in the photo above was sheet-mulched with partly decomposed arborist waste in fall and was planted the following spring. As the photo shows, it produced a healthy crop of brassicas and greens.

CATEC winter cover crop, flowering. Photo: R Morini

 

Cover crop cut close to the ground after flowering. Photo: R Morini

Spring Prep

Cover crop vegetation, if winter-killed, can be left on the soil in spring as a mulch or composted. If winter-hardy, the best practice is to let crops grow until they have flowered, then cut them close to the ground prior to seed formation (see photos). The plants are weakened at that time and less regrowth occurs. Cuttings can be left as mulch or composted. Planting can usually happen conveniently a couple of weeks after cutting, when roots and crowns soften. If cut before flowering, they may regrow. If so, covering with plastic for a month or more or mechanical removal may be needed to prevent regrowth. Another option is to cut planting rows into the cover crop crowns while allowing the cover to regrow alongside the edible crops.

The diverse cover crop above includes crimson clover, forage radish, and winter rye.  The radish was winter killed, and the clover and rye were cut close to the soil with a string trimmer when the crimson clover flowered, prior to seed generation, in April. Regrowth was minimal. Sweet potato slips were planted in raised rows and the space was mulched with 6” of straw that minimized weed growth while generating a nice sweet potato crop (photo below).

While mulching gives up some of the benefits of cover cropping, it enables planting in early spring, prior to cover crop maturity. Cover crops provide other benefits including building strong roots to loosen soil while depositing the products of photosynthesis. Rotating crops year to year allows rotating cover crops and mulch, spreading their varied benefits to different beds.

If there are compaction issues in the bed, loosen the soil with a broadfork or digging fork by driving the fork as deeply into the soil as possible and rocking it back and forth. This reduces compaction without crushing aggregates, disrupting soil life, or lifting buried weed seeds to the surface. If the bed is given a light (up to 2”) covering of compost prior to broadforking, the loosening will help compost penetrate below the surface. Also, building permanent beds and paths helps reduce compaction in the growing spaces while reducing the areas needing soil protection.

Planting 

If trimmed cover crops don’t regrow, seeds and transplants can be planted directly. The photo above shows an agricultural field using a tractor to cut rows for planting while allowing the cover crop to regrow between crop rows. In home gardens we can use hand tools like stirrup hoes to create seed planting rows. Some who are fussy about smooth seed beds, might want to try shallowly-penetrating surface-loosening equipment such as a wheel hoe or tilther. These tools are expensive ($250 and up) but can create a nice seed bed without going deeply into the surface. If there is significant uncovered soil after surface loosening, it is advisable to cover open areas by interplanting, mulching or cover cropping as the main crops are growing.

Interplanting a mix of crops, closely spaced as the photo above shows, is a good way to add diversity to the soil. Also, close planting helps reduce heat impact and moisture loss in the soil below. The goal is to space plants so that their vegetative growth will shade the soil, reducing weeds and watering needs.

If the beds were mulched over winter the practices are similar, except that no crop termination is needed. Move mulch to create rows or planting spaces, then replace it around plants after seeds germinate and plants are tall enough to catch the sun above the mulch.

If the bed was sheet-mulched, seeds and transplants can be planted directly, and interplanted or mulched when the plants are tall enough to stand above it.

In the end, the goal is to keep the soil covered year-round to minimize erosion and runoff, and to manage weeds and moisture while regularly adding sources of organic matter to the growing beds.

Beds idled in summer after spring crop harvest

After spring crops are harvested, usually by the end of July, and if another edible crop is planted right away, follow the spring planting guidance. Vegetation from the harvested plants should be disposed of if diseased but can be chopped for use as mulch or composted if healthy. If the space is not immediately replanted, consider either mulching or a short-term cover crop, like buckwheat. Buckwheat flowers after about 6 weeks, draws pollinators to the garden, and can provide a green mulch or compost additive when cut. After cutting, the space becomes available for a fall edible or cover crop planting.

After fall harvest, the cycle repeats

When the growing season is completed, protect the soil over the coming winter. Space available for cover cropping in September can benefit from a diverse, winter-hardy cover crop. Space available later in the fall, up to late October in Zone 7A, can benefit from a winter-kill crop like Oats, that grows fast, and after frost-killing, creates a mulch layer that will provide winter soil protection. It provides many of the benefits of a winter-hardy crop and allows early planting in spring.

Summary

Following No-Till along with the other regenerative practices noted above is a positive soil and environmental practice:

• Keeps the soil covered with garden crops, mulch, cover crops, or tarps.
• Minimizes soil disturbance and compaction by permanently separating paths and beds and loosening soil with a digging fork or shallow surface-loosening equipment rather than deeper penetration with a tiller or shovel.
• Maximizes living roots in the soil by rotating and interplanting crops and using diverse cover crops among or in place of garden crops, during and between growing use.
• Energizes soil with diversity by increasing the mix, density, and location of mulches, edible crops, and cover crops.

While the percentage of US farmers, growers, and home gardeners that use No-Till practices is small, it is growing. The data that supports no-till is strong. While the deep tilling and chemical fertilization practices of the last 100+ years helped feed a fast-growing population, its negative effects on soil and the environment call for changes like those discussed above, sooner rather than later. I hope the suggested techniques are clear, simple, and motivating enough to justify making the change. It is important for the soil and the planet.

Sources:

The Advantages of a No Till Home Garden: https://s3.wp.wsu.edu/uploads/sites/2073/2020/09/No-till-Garden-Advantages.pdf#:~:text=If%20you%20would%20like%20to%20convert%20your%20garden,make%20the%20paths%20wide%20enough%20for%20your%20mower.

Low and No Till Gardening: https://extension.unh.edu/blog/2020/10/low-no-till-gardening

Converting to No Till for Home Gardeners: https://extension.unl.edu/statewide/cass/Smart%20Gardening%20Converting%20to%20No-Till%20for%20Home%20Gardeners%20Sept%202018.pdf

Weed Control in No Till Gardens: https://extension.sdstate.edu/weed-control-no-till-gardens

Vegetable No Till Garden: https://plants.ces.ncsu.edu/garden_detail/vegetable-no-till-garden/

Using Cover Crops and Green Manures in the Home Vegetable Garden: https://hort.extension.wisc.edu/articles/using-cover-crops-and-green-manures-home-vegetable-garden/

Cover Crops and Green Manures in Home Gardens:  Cover crops and green manures in home gardens | UMN Extension

Tips for Planting Cover Crops in the Home Garden:  https://extension.psu.edu/tips-for-planting-cover-crops-in-home-gardens

Layer Compost “Lasagna Style” for No Till Gardening:  https://extension.oregonstate.edu/news/layer-compost-lasagna-style-no-till-gardening 

Tarps, Mulch and Timing: No Till Tools to Rob the Weed Seed Bank:  https://smallfarms.cornell.edu/2023/04/tarps-mulch-and-timing-no-till-tools-to-rob-the-weed-seedbank/

Regenerative Agriculture and How to Apply it to our Home Gardens: https://piedmontmastergardeners.org/article/its-all-about-the-soil/