Tillage Radish: The Best Cover Crop For Soil Health
Tillage radish is Daikon radish, a powerful cover crop for enhancing soil health. It effectively breaks up compacted soils and clay, while simultaneously improving the fertility of low-quality soil and getting it ready for planting.
This article tells you everything you need to know about this practice and explains, step-by-step, how to plant daikon radish as a cover crop in your home garden.
Would you like to save this page?
We'll email you a link to this post, so you can come back to it later!
Benefits of Cover Crops
Cover crops provide various benefits to gardeners and the garden ecosystem.
They act as a living mulch or green mulch, as well as being considered green manure when allowed to die back inside and on top of the soil.
They enhance soil fertility by fixing nitrogen, preventing soil erosion, suppressing weeds, supporting beneficial insects and pollinators, and improving soil health and structure.
Cover crops can be used in any gardening method you practice: no-till/no-dig, conventional, organic, back to Eden, whatever — it doesn’t matter.
How Cover Crops Like Tillage Radish Work
Bare soil is hungry soil. It is pretty important to keep the soil covered or planted all of the time.
When we’re in between crops in our vegetable gardens, and we leave our beds bare, the beneficial microbes in the soil go hungry. This leads to poor-quality soils and also allows bad bacteria, bad microbes, and unwanted pests to flourish and even take over.
Bare soil is also more likely to become compacted through time and weather events like rain and snow — and it is guaranteed to be more full of weeds if kept that way.
When tillage radish and other types of daikon radish are planted, the root gets to work growing down and breaking up the soil. Then the taproot gets down even longer and brings up more minerals and nutrients instead of letting them be washed away.
The green tops of the radish grow a lush, thick canopy that shields the soil and reduces weeds.
As the frost comes, the crop is killed. You can then chop down or mow the green tops, or leave them to die naturally if your area gets cold enough.
The Tillage Radish starts to decay and be eaten by bacteria, microbes, and other soil dwellers (like earthworms), leaving behind a rich nutritious organic matter.
It’s like composting at this point, just directly in the soil.
The following spring, the radish continues decomposing, and the resulting nitrogen and nutrients are left behind in the soil for your own crops.
Benefits of Daikon Radish Cover Crops
- Improves soil structure and reduces compaction.
- A cover crop acts as a living mulch or green mulch.
- Breaks up compacted soil layers, allowing better root penetration and water movement.
- Enhances nutrient cycling by drawing up nutrients from deeper soil layers.
- Suppresses weeds through shading and competition.
- Attracts beneficial insects, improving natural pest control.
- Provides a deep taproot that helps alleviate soil compaction and brings up minerals.
- Increases organic matter content when incorporated into the soil.
- Improves water infiltration and reduces runoff.
- Helps control nematode populations through biofumigation.
- Acts as a winter cover crop, protecting soil from erosion and nutrient loss.
Daikon radish might be the best cover crop, and it has a place in multiple situations, which makes it truly versatile and remarkable.
- Your home vegetable garden.
- Permaculture gardens and perennial beds.
- A larger market garden.
- Raised beds.
Daikon radish is now commonly used for tilling soil on many large, industrial farms, but its origins lie in Japan, where it is a staple in natural and organic farming.
Masanobu Fukuoka, a pioneer of natural farming methods in Japan, used daikon extensively. In his book The One Straw Revolution he states: “If the soil is hard, grow Japanese radish first.”
In Japanese cuisine, Daikon radish is a staple ingredient that can be eaten raw, cooked, or pickled and fermented.
The type of daikon radish you plant as a cover crop does matter — there are countless varieties.
In my fall raised bed vegetable garden, I will grow smooth, golf ball-sized daikon radishes to be fermented and enjoyed as a winter vegetable, not as a cover crop.
Next to my raised beds in the large plot of earth that I’m transforming into a no-till garden this year, I’m specifically planting tillage daikon radish.
The bed in question is full of noxious weeds and severely compacted soil that is poor quality and starved of nutrition.
Instead of using a roto-tiller, as in conventional gardening that needlessly adds extra (and destructive) tasks, I am planting radishes to fix and amend the hard soil in a way that works with nature and not against it.
Crazy concept I know.
Using radish to till the soil is not only significantly easier — and cheap but also better for the soil. The radish rots and decomposes in the ground, feeding the soil microbes, while the leaves become green mulch.
By using radishes as a natural rototiller, I can avoid bringing weed seeds to the surface, resulting in fewer weeds over time.
So you want to plant a radish varietal that grows very large and fast, has a long taproot (to mine minerals and nutrients), and grows big green leaves to shade out the soil beneath.
(Follow along with me on my Instagram where I’ll be documenting this entire process.)
Tillage Radish vs Daikon Radish — Is Daikon Radish The Same As Tillage Radish?
Yes and no. Although note that I will use them sometimes interchangeably in this article.
Tillage radish is a type of daikon radish, but the name ’tillage radish’ is specific to a particular genetic strain bred to produce a fast-growing and very large radish with a deep taproot.
When you see it written like this: Tillage Radish®, you know you’re dealing with a specific, patented seed and the name is trademarked.
Daikon radish is any daikon radish.
There are numerous varieties and hybrids of daikon, just like any other plant.
Compared to daikon radish, which may be eaten or used as a cover crop, tillage radish is only ever specifically utilized as a cover crop.
And you don’t have to buy “tillage radish” seeds specifically — make sure you’re buying a variety of daikon that grows large, long, and fast.
Find a bulk source of seeds versus those small packets. It is considerably cheaper this way, and I’ll provide you with some sources to buy tillage radish at the bottom of this article.
You may find varieties of daikon radish sold under: tillage radish, Tillage Radish®, forage radish, fodder radish, groundhog radish, and more.
How To Plant Daikon Radish as a Cover Crop (Step-By-Step)
- Timing: For a thick leaf canopy, plant daikon 4-10 weeks before the first frost, which occurs in late August in cooler climates and early September in warmer ones.
- Prepare the soil surface: Clear the planting area of any existing vegetation and mulch. Consider cutting any weeds or spent plants down at soil level and allowing the roots to remain. Remove weeds by hand or mow them down. Remember that you risk bringing up more weed seeds if you opt to till the soil.
- Sow the seeds: Broadcast the daikon radish seeds evenly over the prepared soil surface. Aim for a seeding rate of about 10 to 15 seeds per square foot, ensuring good seed-to-soil contact (more on this below).
- Lightly press the seeds or sprinkle with soil or compost: Use a garden rake or the back of a small shovel to press the seeds into the soil gently. Conversely, sprinkle a thin layer of soil or compost on top of the seeds. Do not mulch.
- Water thoroughly: After planting, thoroughly water the area to provide adequate germination moisture. Keep the soil consistently moist throughout the germination period (more on germination below).
- Monitor growth: Check the progress of the daikon radish cover crop. It should start germinating within a week or two depending on the weather conditions.
- Maintain adequate moisture: Throughout the growing period, provide sufficient moisture to the daikon radish plants, especially during dry spells. Adequate water is essential for healthy growth.
- Allow natural decomposition: Instead of tilling the daikon radish plants, which some commercial farms do, let them decompose naturally inside the ground. This process contributes to soil organic matter and nutrient release. It also attracts earthworms.
- Reap the benefits: As the daikon radish cover crop decomposes, it enhances soil structure, increases organic matter content, improves nutrient availability, suppresses weeds, and supports overall soil health in your no-till organic garden.
Remember to adjust the specific steps based on your local growing conditions and the daikon radish seed package recommendations.
If you live in an area without frost, you must mow down or chop down the green radish tops. You can use them as a chop-and-drop mulch to further protect and enhance your soil.
If you’re working on rebuilding very poor-quality, compacted soils, you should add compost too. And consider a thick layer of additional mulch if you can access it.
Amending the soil this way in the fall will yield incredible results for the following spring when it is time to plant new vegetables.
See my article on adding compost to garden in fall and my article on improving garden soil over winter for more information.
These are all-natural, low-tech, and affordable ways to improve soil and boost its fertility.
When To Plant Tillage Radish
- Tillage Radish®: for this specific trademarked variety, plant your cover crop in late summer to early fall, ideally 4 weeks before the average first killing frost date. The Tillage Radish® seed will germinate very quickly and start appearing within a few days after planting. It grows incredibly fast with a very long taproot.
- Daikon Radish Cover Crop: for other daikon radish varietals, if you want a thick leaf canopy, plant seeds 4-10 weeks before the first frost. See your specific seed packet for more details.
Tillage Radish Seeding Rate
- Broadcasted: 10-12 lbs per acre.
- Drilled: 6 lbs per acre
- Cover Crop Mix: 2-4 lbs per acre
- Precision Planted: 4 lbs per acre
- Raised Bed: 10-15 seeds per square foot, but don’t be afraid to add more
- Garden Beds (Broadcasted): 1/2 a pound per 100 square foot of garden, and up to 1 pound if the garden beds are very weedy and covered in mulch or other organic matter.
How many seeds are in a pound of tillage radishes?
There are 20,000 to 25,000 seeds per pound approximately.
Related Articles
- How To Improve Garden Soil Over The Winter {According To Experts}
- When To Add Compost To Garden Beds {Fall or Spring?}
Tillage Radish Is The Best Cover Crop For Clay Soil
Tillage radish is the ideal cover crop for those dealing with clay soils.
Clay soil is a heavy, compacted soil type characterized by fine particles that retain water and have poor drainage.
Planting radishes achieves the same result as using a rototiller and compost but with much less effort. And with radish, you don’t unearth weed seeds that will plague you the following year.
You should still add compost as mulch to your soil for the best benefits, but even without compost, or very little of it, a radish cover crop planting in the autumn still offers tremendous benefits.
Can You Eat Tillage Radish?
Yes, you can eat tillage daikon radishes, much as you can eat all other daikon radishes you plant. It is quite tasty and slightly less spicy than some other types.
But it would completely nullify the point of planting it as a cover crop.
One of the key elements of tillage radish planted as a cover crop is to allow the thick root to break up soil and then decompose to feed the soil. And to allow the even longer and more slender taproot to mine the earth for minerals which will be brought up into the root and leaves.
There is nothing wrong with pulling up a few to eat. You can eat tillage radish raw, cooked, pickled or fermented.
Related Articles
No-Till Gardening {Everything You Need To Know}
Final Thoughts
Tillage radish proves to be an exceptional cover crop for enhancing soil health and fixing clay and compacted soils. Its deep root and taproot aid in soil aeration, nutrient cycling, and compaction alleviation. Tillage radish breaks up compacted soil, improving its structure and promoting better water infiltration. Additionally, the extensive root system acts as a dynamic organic matter source, contributing to soil fertility and microbial activity. With its numerous benefits and minimal maintenance requirements, tillage radish stands out as a valuable choice for both farmers and gardeners seeking to improve the health and productivity of their soil.
