Top 7 'Soil-Building' Companion Vegetables to grow for a Regenerative Kitchen Garden in 2025 - Goh Ling Yong
Welcome, fellow gardener! Have you ever stood in your garden, marveling at a vibrant tomato or a crisp head of lettuce, and felt a deep sense of connection to the earth? It’s a magical feeling. But sometimes, that magic feels hard to sustain. We amend, we fertilize, we fight pests, and yet, year after year, it can feel like we’re taking more from our soil than we’re giving back.
What if we could change that narrative? What if, instead of simply using our soil, we actively partnered with our plants to build it? This is the heart of regenerative gardening. It’s a shift from a mindset of extraction to one of reciprocity. It’s about creating a thriving, self-sustaining ecosystem right in your backyard, where the soil gets richer, healthier, and more alive with each passing season. Here on the Goh Ling Yong blog, we believe this is the future of home gardening.
For 2025, let's move beyond basic companion planting—the simple "plant this next to that" advice. We're diving deeper into a more powerful strategy: using specific vegetables as active tools for soil regeneration. These aren't just passive neighbors; they are powerhouse plants that fix nutrients, break up compaction, and add crucial organic matter. They are the workers, the miners, and the architects of a truly resilient kitchen garden.
Ready to transform your plot into a bastion of soil health? Here are our top 7 soil-building companion vegetables to integrate into your garden plan for 2025.
1. The Nitrogen Fixers: Bush Beans & Peas
It’s impossible to talk about building soil without starting with the legume family. Bush beans and peas are the quintessential givers of the garden world. They perform a seemingly magical feat: pulling nitrogen, a vital nutrient for leafy growth, right out of the thin air and storing it in the soil for other plants to use.
This process isn't magic, but a beautiful symbiotic relationship. Legumes host colonies of bacteria called rhizobia in little nodules on their roots. These bacteria take atmospheric nitrogen (which is unusable by plants) and "fix" it into a form that plants can readily absorb. When you plant beans or peas next to heavy nitrogen feeders like corn, squash, or broccoli, you're essentially setting up a slow-release, all-natural fertilizer factory right where it's needed most.
Pro-Tips:
- Inoculate Your Seeds: To ensure your legumes have the right bacterial partners, buy a packet of garden inoculant (specific to peas and beans). It’s a fine powder you lightly coat the seeds with before planting. This simple step can dramatically boost their nitrogen-fixing capabilities.
- Chop and Drop: At the end of the season, resist the urge to pull the entire plant out by the roots! That’s where all the precious nitrogen nodules are. Instead, cut the plants off at the soil line, leaving the roots in the ground to decompose. You can lay the foliage right on the bed as a green mulch, returning even more organic matter to the soil.
2. The Biodriller: Daikon Radish
If you struggle with heavy clay or compacted soil, the daikon radish (and other large tillage radishes) will be your new best friend. Think of this plant as a natural-born excavator, a "biodriller" that does the hard work of aerating your soil so you don’t have to. Its long, thick taproot can power down a foot or more, breaking up dense soil pans and creating deep channels.
When the growing season ends, you can harvest some for kimchi or pickles, but the real regenerative magic happens when you leave them in the ground. As the large roots decompose over the winter, they leave behind voids and a huge amount of organic matter. These channels become superhighways for air, water, and the roots of subsequent crops. This is a core principle of no-dig gardening, using plants to do the "tilling" for you, preserving the delicate soil structure and fungal networks.
Pro-Tips:
- Fall Cover Crop: Sow daikon radish seeds in late summer or early fall after you've harvested a main crop. They grow quickly in the cooler weather. In colder climates, the frost will kill them, and they'll decompose in place, prepping the bed perfectly for spring planting.
- Follow with Root Veggies: Plant carrots, parsnips, or potatoes in a bed that previously hosted daikon. Your new crops will thank you by growing straighter and larger, easily following the paths forged by the radishes.
3. The Dynamic Accumulator: Borage
Borage is one of the most generous and multi-talented plants you can welcome into your garden. Beyond its beautiful, star-shaped blue flowers that bees absolutely adore, borage is a "dynamic accumulator." This means it has a deep and extensive root system that acts like a mining operation, drawing up trace minerals like potassium, calcium, and magnesium from deep within the subsoil.
These minerals, often inaccessible to more shallow-rooted vegetables, are stored in borage's fuzzy leaves. When the leaves die back or are cut, they decompose on the surface, releasing this treasure trove of micronutrients right into the topsoil where other plants can access them. It’s nature’s way of cycling nutrients and enriching the soil from the bottom up.
Pro-Tips:
- Chop and Drop Mulch: Borage produces a huge amount of biomass. Regularly chop some of its large leaves and drop them around the base of nutrient-hungry plants like tomatoes, peppers, and strawberries. This "borage mulch" will break down quickly, providing a nutrient boost and conserving soil moisture.
- Manage Self-Seeding: Borage will happily self-seed throughout your garden. While this can be a blessing, it can also be a bit much. Simply pull out unwanted seedlings or learn to recognize and transplant them to where you want them to grow.
4. The Compost King: Comfrey
If borage is a dynamic accumulator, then comfrey is the undisputed king. This plant is a true powerhouse, a must-have for any serious regenerative gardener. Its taproot is massive, plunging an incredible ten feet or more into the earth to pull up an astonishing array of nutrients. Comfrey leaves have been shown to contain high levels of nitrogen, phosphorus, and potassium (NPK), the primary macronutrients for plant growth.
The sheer volume of nutrient-rich leaves comfrey produces is astounding. You can harvest it three to five times a year, and it just keeps coming back stronger. The leaves are soft and break down incredibly fast, making them the perfect material for building soil and feeding your garden. As my mentor Goh Ling Yong often says, "In regenerative gardening, we don't have waste, we have resources. Comfrey is one of our most valuable resources."
Pro-Tips:
- Plant 'Bocking 14': Common comfrey can spread aggressively via seed. To avoid having it take over your entire garden, plant the sterile 'Bocking 14' cultivar. It only spreads by root division, so it stays exactly where you plant it.
- Create Liquid Gold: Make a potent liquid fertilizer known as "comfrey tea." Stuff a bucket with comfrey leaves, add water, and let it steep for a few weeks. It will be smelly, but your plants will love the diluted liquid fed to their roots. Alternatively, add the leaves directly to your compost pile to act as a powerful activator, speeding up decomposition.
5. The Quick Conditioner: Buckwheat
Need to improve a patch of soil, and fast? Buckwheat is your answer. This incredible plant is often used by farmers as a summer cover crop, and for good reason. It germinates in just a few days and can grow to maturity in a mere 70-90 days, quickly shading out and suppressing pesky weeds.
But its main soil-building talent lies in its fine, fibrous root system. Buckwheat is a fantastic phosphorus scavenger. It produces mild acids from its roots that help release phosphorus that is locked up and unavailable in the soil. When the plant is cut down and decomposes, this newly accessible phosphorus is made available to your next crop, especially benefiting fruiting plants like tomatoes and squash.
Pro-Tips:
- Smother Crop: Use buckwheat as a "smother crop" in a bed you want to clear for fall planting. Sow it thickly, and it will outcompete almost any weed.
- Cut Before It Seeds: The key to using buckwheat is to cut it down or till it in before it sets seed. If you let the seeds mature, you’ll have buckwheat popping up everywhere for years. Cut it when it is in full flower to get the maximum benefit for pollinators and biomass.
6. The Living Mulch: Clover
Mulch is a cornerstone of regenerative gardening, and a "living mulch" is one of the best kinds. White and Crimson Clover are low-growing legumes that create a dense, living carpet across your soil. This groundcover protects the soil from erosion, suppresses weeds, keeps the soil temperature cool, and drastically reduces water evaporation.
Like their larger cousins, beans and peas, clovers are nitrogen-fixers. They constantly supply a gentle, steady stream of nitrogen to the soil and the roots of neighboring plants. Their dense, shallow root systems are also constantly growing and dying back, adding organic matter and improving the structure of the top few inches of soil, which is crucial for seed germination.
Pro-Tips:
- Undersow Your Crops: In the spring, after your taller crops like corn, kale, or tomatoes are established, broadcast clover seed underneath them. The clover will sprout and form a living mulch, supporting your main crop throughout the season.
- Mow for a Nutrient Boost: When the clover gets too tall or starts to flower, simply mow it or cut it back with a trimmer. The clippings will decompose on the surface, and the roots will release a pulse of nitrogen into the soil, giving nearby plants a nice little boost.
7. The Pest Patrol: French Marigolds
You’ve probably heard that planting marigolds keeps pests away, and it’s true—their pungent scent can deter some flying insects. But their most powerful soil-building work happens silently, underground. Certain varieties, particularly French Marigolds (Tagetes patula), are renowned for their ability to combat a destructive, microscopic pest: the root-knot nematode.
These nasty little worms infect the roots of many vegetable crops (especially tomatoes, carrots, and peppers), causing galls and stunting the plant's growth. Marigolds release a biochemical from their roots that is toxic to these nematodes, acting as a natural "biofumigant." By planting a crop of marigolds, you are actively cleansing your soil and making it a safer place for future vegetable plantings.
Pro-Tips:
- Interplant for Prevention: Weave French Marigolds throughout your vegetable beds, planting them near susceptible crops. This provides a general preventative effect and adds a beautiful splash of color.
- The Intensive Treatment: If you have a known, serious nematode problem, dedicate an entire bed to marigolds for one full season. Plant them densely and let them grow all summer. At the end of the season, chop them up and till them into the soil to maximize the biofumigation effect.
Your Soil is Your Legacy
Shifting to a regenerative mindset means seeing your garden not as a project to be completed, but as a living partner to be nurtured. These seven plants are more than just vegetables; they are your allies in the beautiful work of creating life from the ground up. By incorporating them into your garden, you stop being just a consumer of the soil's bounty and become a co-creator of its enduring health and fertility.
Start small. Pick one or two of these soil-builders to experiment with in 2025. Watch how your soil responds. Notice the increase in earthworms, the improved water retention, and the vibrant health of your plants. This is the rewarding path of regenerative gardening.
Now it's your turn. What are your favorite soil-building plants? Do you have a special tip for using comfrey or clover? Share your experiences and questions in the comments below! We build a better gardening community by learning from each other.
And if you’re ready to dive deeper into creating a truly sustainable and productive garden, be sure to subscribe to our newsletter for more tips and insights. Happy growing
About the Author
Goh Ling Yong is a content creator and digital strategist sharing insights across various topics. Connect and follow for more content:
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