x
 
 
Learn which plants thrive in your Hardiness Zone with our new interactive map!

How to Use Unfinished Compost in Planting Bed

By Dawn Walls-Thumma ; Updated September 21, 2017
Some plants, like corn, will thrive in partially finished compost.

Composting is a natural process during which soil microbes break down plant and animal matter into healthy, nutrient-rich soil. Kitchen scraps and yard waste make excellent compost, leading many gardeners to pursue composting as an inexpensive and eco-friendly alternative to conventional fertilizers. Because it relies on microbes to do all of the work, the breakdown of ingredients may take weeks, even months, depending on conditions. While using immature compost is generally not advisable--the University of Illinois Extension points out that soil microbes will compete with plants for nitrogen and stunt their growth--some crops thrive in what is known as "lasagna composting," and unfinished compost makes an excellent mulch.

Lasagna Composting

Dig a hole or a trench, in the fall, that is deep enough to accommodate your composting materials while leaving them slightly mounded. Compost will shrink as it decomposes.

Spread a layer of half-finished compost on the bottom.

Add additional layers, alternating "green" and "brown" ingredients. Nitrogen-rich ingredients, called greens, include grass clippings, kitchen scraps and just about anything else that is fresh or still moist. Carbon-rich ingredients, called browns, include dry ingredients, such as fallen leaves or paper shreds. Allow the compost to work over the winter.

Plant peas, beans, squash, potatoes or corn into the unfinished compost bed in the spring.

Mulching

Plant your vegetables or flowers in the spring.

Dress the area around the plants with 2 to 3 inches of partially finished compost. Unfinished compost is safe to use as mulch for all species, as it will not compete for nitrogen with the plant's root system.

Reapply the mulch as needed, usually once or twice per year. Unfinished compost used as mulch will continue to decompose, providing the plant with nutrients as it does so.

 

Things You Will Need

  • Shovel
  • Half-finished compost
  • Additional composting ingredients
  • Seeds or seedlings (peas, beans, corn, squash and potatoes only)

Tip

  • When gathering ingredients for lasagna compost, err on the side of providing more brown ingredients rather than green ingredients. Green ingredients promote bacterial reproduction, while brown ingredients act as food, so too many greens can mean that you end up with a surplus of bacteria and not enough for them to eat. "Rodale's Ultimate Encyclopedia of Organic Gardening" recommends use two parts brown for one part green, although this is more of a guideline. Precise ratios are not essential.

Warning

  • Do not plant species other than legumes, squash, potatoes or corn in unfinished compost or work unfinished compost into the soil for any plants but these species, as it will cause stunted growth and yellowing of the leaves.