![Tiller](https://cdn.statically.io/img/www.southernliving.com/thmb/51aD4cITyA8_rE6inxQBq7Bp9ZI=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/GettyImages-1392060367-b69c04b7edf8465d847bbf0c70a571b1.jpg)
vitranc/Getty
Warmer weather means spending more time outside, dreaming about planning and preparing your garden space. But before you can begin sowing seeds or planting starters like strawberries, tomatoes, or sunflowers, you’ll need to make sure the soil is ready. One way to prepare the soil is by tilling, which is when you turn over the soil and add amendments to get it ready for planting. But not every gardener agrees that tilling is the best method, and it's not always clear when you should or shouldn't till a garden bed. To help clear up the confusion, we've talked to experts about the benefits and pitfalls of tilling as well as the best ways till your garden.
What Is Garden Tilling?
Garden tilling is the process of turning over the top layer of soil, breaking it up, and adding air to the soil. “This will help the roots of your plants be able to move more easily through the soil,” says Kim Roman, expert gardener for Square Foot Gardening 4 U, an online source for gardening classes, and author of How to Garden Indoors & Grow Your Own Food Year Round. Loosened soil also helps plants receive all the different nutrients they need to grow.
Tilling can be done manually or with a motorized tiller, also called a rototiller. However, tilling can cause more harm to your soil than good in some circumstances, so you’ll want to consider whether it makes sense for your area and needs.
Does Tilling Harm Soil Health?
Tilling the soil isn’t something that should be done frequently—in fact, there is controversy over whether it should be done at all. The old-school practice of annual tilling can be harmful for a number of reasons.
“If tilling is done too often, it can change the soil structure,” explains Angelo Randaci, master gardener and horticulture expert at Earth’s Ally. “This can cause soil runoff and erosion.”
Randaci adds that tilling can compact the soil further below. “This is called a hard pan and this will make it difficult for roots to expand below the tilled depth,” he says.
Not only that, but tilling may appear to clear your bed of weeds only to have the opposite result. “Tilling is not just bad for the soil structure; the act of roto-tilling brings up soil from below and reactivates weed seeds,” Roman explains. Suddenly, you'll find weeds sprouting all over your garden.
And while it can give weeds a leg up, tilling harms beneficial soil organisms. “Tilling disrupts the animal life in the soil such as worms and microorganisms that help provide soil health,” says Randaci. With healthy soil, these microorganisms naturally turn over, aerate, and enrich the soil in your garden.
What Is The Best Way To Till?
Manual tilling is often considered a better choice than using a rototiller but is also up for debate since it still affects the soil structure. Tilling by hand is usually done in small spaces. “Hand tilling is less invasive, but still disrupts the structure of the soil, and is a lot of hard work,” says Janet Sluis, horticulturist and curator of Sunset Plant Collection.
On the other hand, machine-powered tillers get a bad rap for having a bigger impact on the soil. If the job is too big to tackle by hand, there are alternatives. “The reason rototillers can be problematic is because they are designed to dig deep into the ground and pulverize the soil structure, but there are other tools that are helpful for limiting the depth of your tillage,” explains Tools Product Manager Jen Goff of Johnny's Selected Seeds. “Power harrows are a common tool for reduced tillage because the blades are oriented vertically and do not work the soil as deep."
The final takeaway: Minimizing tilling has been shown to be better for the soil and microorganisms. “There is quite a bit of university research that suggests reducing tillage can be beneficial to your garden soils and reduce weed pressure by limiting the number of weed seeds brought up to the soil surface to germinate,” says Goff. “Reduced tillage can help maintain the soil structure and soil biology that supports crop health.”
When Is Tilling Helpful?
The size of the garden and whether the soil is compacted or loose will help determine if you should till. “Tilling (or manual double digging) is usually done if the soil is heavily compacted, for heavy clay soils, and when you want to add a lot of nutrients or other amendments into the soil, like for a vegetable garden,” shares Sluis.
Motorized tillers can save time and physical labor if you have a large area that has never been used before and "can be very helpful for breaking new ground,” says Goff.
If you do choose to till, it’s a good idea to conduct a soil test through your local extension service, which will provide insight into what amendments your soil may need. “The test will also tell you what nutrients your soil is deficient in, and now is the time to add fertilizers and other trace minerals,” shares Roman. “Don’t add fertilizers, other than compost, unless you’ve run a soil test.”
The Best Time Of Year To Till A Garden
Tilling a garden is typically done after the last frost, usually in early spring and sometimes in the fall, to prepare the soil for planting. “The garden can be tilled in the fall as part of the fall cleanup or anytime before planting,” says Randaci. Before you begin, you need to make sure the soil is workable and crumbly—not too dry or too wet.
With wet soil, “compaction doesn’t allow for air space between soil particles which is needed for your plant roots to breathe,” explains Roman. But if the soil is too dry, it can also create problems. “Tilling dry soil could pulverize the soil particles,” Roman says, and that can lead to erosion and compaction.
How To Test If Your Soil Is Ready To Till
Wondering how to know if your soil is too wet or dry for tilling? You can do a quick check by picking up a handful of soil and creating a ball. Roman suggests following these steps to test:
- Take a garden trowel and dig a handful of soil down to a depth of 6 inches.
- Hold the soil in your hand and try to squeeze it into a ball.
- "If it doesn’t form a ball, then your soil is too dry, or too sandy,” Roman says. Water the ground, wait a couple of days and then test again.
- If you can form a ball, “Hold the ball in the palm of your hand and press your thumb to the center, says Roman. “If it breaks up nicely, then you should be able to till your soil.” But if it's so solid it won't fall apart or easily break up, then it's too wet. Let the ground dry out for three days and test again.
How To Till A Garden With A Rototiller
Before you start tilling, you’ll need to check the area and ensure there is no debris. “Pull any vines you see or they may become tangled in the tines of your rototiller,” says Roman. Also, make sure to determine the locations of any underground wires or pipes before you begin.
If the soil test shows you have a lot of clay, you can add amendments that will help loosen the soil. “Soils with too much clay and too much sand can both be remedied by lots of good organic matter like compost,” Roman says.
Finally, “don’t forget your safety equipment: googles, hearing protection, gloves, long sleeves, and long pants as the machine can kick up soil or rocks,” says Roman. Now you're ready to start tilling.
- If the ground is very hard or you are tilling the area for the first time, use the shallowest setting. Start in one corner and keep moving forward until you reach the end of the bed. Walk slowly, watching for rocks and other hazards and allowing the tines to do their job of breaking up the soil.
- Once you've finished, go over the area a second time at a depth of 8 inches.
- If you're adding amendments like compost or other nutrients (preferably based on recommendations after a soil test), do so and then pass over the soil with the tiller a third time. If you haven't had a soil test done, you can add 3 inches of compost on a poor sandy soil or heavy clay soil.
- Rake the soil smooth with a landscape rake.
What Is The Best Alternative To Tilling?
Especially if your garden bed has been used in prior years, consider using a broad fork for a less invasive approach. This heavy-duty tool looks like a rake with five to eight thick tines and doesn’t really “till” but aerates and minimally breaks the soil.
“A broadfork and a good bed preparation rake can be plenty for the small market farm or home garden, as long as you are breaking up the compaction beneath the soil surface and creating a smooth bed top," Goff says.
Most garden spaces that are used year after year only need a little compost, which can be added on top and lightly mixed in with a digging fork. “Just place a layer on top of the soil, and work a little into the soil with the fork,” says Sluis. “This does less damage to earthworms and overall soil structure.” Now you're ready to get planting.