Skip the Fertilizer: These 6 Inflation-Proof Plants Feed Your Garden for Free

Fertilizer prices are rising due to global supply disruptions, which can impact the cost of countless home and garden supplies. The good news? You don’t need to invest in store-bought fertilizer to grow a healthy garden.

With strategic planting, you can grow your own soil boosters from seed. Mixing nitrogen fixers with fast-growing nutrient scavengers helps build better soil, cut costs, and keep your beds productive all season long.

These six plants help in a few ways: they add nitrogen, create compost material or can be cut and left in place to feed the soil as they break down.

Nitrogen Fixers

Nitrogen is a key nutrient for leafy growth, strong stems, and healthy green foliage. These easy-to-grow plants naturally add it back to the soil while also improving garden beds over time.

Garden Peas

Garden peas (Pisum sativum) are one of the easiest ways to boost your soil early in the season. As a legume, they partner with beneficial soil bacteria to “fix” nitrogen, converting it from the air into a form that plants can use.

Plant peas in early spring as soon as the soil is workable. After harvest, cut the plants at the base and leave the roots in the ground so the stored nitrogen in the root nodules can return to the soil as they break down.

The leftover vines are perfect for compost. They decompose quickly, adding fast-acting organic matter that feeds both your compost pile and your garden.

Green Beans

Green beans (Phaseolus vulgaris) are a true double-duty summer staple, easy to grow, widely available and beginner-friendly. Like peas, they are legumes that work with beneficial soil bacteria to fix nitrogen, helping improve soil fertility while producing a steady harvest.

These fast-growing plants are ideal for succession planting, so you can keep both your harvest and soil benefits going all season. When the plants are finished, cut them at the base and leave the roots in place so nitrogen can be released back into the soil. Add the remaining plant material to your compost pile to recycle nutrients and build organic matter.

Clover

Clover (Trifolium spp.) is a true multitasker in the garden. Like beans and peas, it’s a nitrogen-fixing legume that works with beneficial soil bacteria to convert nitrogen from the air into a usable form, improving soil fertility. It also helps loosen compacted soil, suppress weeds, prevent erosion, and attract pollinators.

You can use either white clover (Trifolium repens) or red clover (Trifolium incarnatum). Both are easy to find, inexpensive and effective as cover crops. For most garden beds, an annual type like red clover is the better choice since it won’t reseed and spread the way perennial white clover can (unless you want it as a lawn alternative). Clover also acts as “green manure,” meaning it’s grown to be cut and returned to the soil, where it breaks down and adds nutrients and organic matter.e.

Nutrient Scavengers

Not every soil-boosting plant fixes nitrogen. Some, especially leafy greens, work as nutrient scavengers, soaking up nutrients that might otherwise leach from the soil with rainfall. When their leftover growth breaks down, those nutrients are returned to the soil or compost, helping keep them in your garden system.

Lettuce

All lettuces (Lactuca sativa) are fast fillers that also feed your compost. They grow quickly in cool weather and are perfect for filling empty garden space early in the season. While lettuce isn’t a nitrogen fixer, it produces soft, nitrogen-rich material that breaks down easily in compost.

Sow seeds directly in early spring as soon as the soil is workable, spacing lightly for baby greens or thinning as they grow. For a steady supply, succession plant every 1–2 weeks to keep tender leaves coming. Its cut-and-come-again habit allows for multiple harvests before plants are eventually returned to the soil or compost to keep the nutrient cycle going.

Spinach

Spinach (Spinacia oleracea) offers quick growth with big soil benefits. While it isn’t a nitrogen fixer, it produces tender leaves that break down easily, making it ideal for compost or chop-and-drop mulching. It thrives in cool weather and works well before planting warm-season vegetables or again in fall.

Harvest spinach cut-and-come-again-style and succession plant every 1–2 weeks so they grow steadily. To speed up germination, soak seeds overnight before planting. This softens the seed coat and helps water penetrate more easily, leading to quicker, more even sprouting. Once plants finish producing, turn them back into the soil or compost to recycle nutrients and build organic matter.

Mustard Greens

Mustard greens (Brassica juncea) are speedy growers that build soil fast. One of the fastest-growing leafy crops, they produce plenty of biomass in just a few weeks. They’re also edible and nutritious, with a peppery flavor that works well in salads, stir-fries and condiments.

Sow seeds directly in early spring or fall for best results. When the plants are finished, chop and turn them into the soil to add organic matter and nutrients. This makes them an excellent choice for refreshing garden beds between plantings and keeping soil active during slower growing periods.