What is “Chop and Drop?” How to Recycle Old Plants to Generate New Growth

By Amanda Rose Newton

With every season change, we see a change in the variety of plants present in our landscape. One plant’s expiration date is another plant’s beginning. But don’t despair — those deceased plants can still offer a wealth of service in your garden, as, through the magic of decomposition, the available nutrients are slowly leached into the soil, ready to be taken up by hungry new plants. 

In the worlds of regenerative agriculture and permaculture, this practice is colloquially referred to as, “chop and drop.”

What is Chop and Drop?

This is certainly one of those instances where the name says it all! You “chop” (or cut) the old plant material and “drop” it on the ground, mimicking what plants would do if undisturbed in nature. When plants die (or dieback), old material falls to the ground, decomposes and contributes food for the soil organisms (fungi, bacteria and animals) while resulting in that beautiful compost-like humic layer. This method also keeps the roots in the soil, where they prevent erosion and help maintain aeration.

When is the right time to chop and drop?

While the concept might make sense and seem simple, it’s like anything else — there are times when it is appropriate to use this regenerative farming method and times when it is not. Plants that tend to have deep tap root systems, produce a lot of leafy material and fix nitrogen are the ideal choices for this practice.

Those deep-reaching roots can surpass some of the smaller, more fibrous roots of your garden veggies. By leaving them in the ground as-is, you are giving other plants access to the nutrients that have accumulated.

Perennial legumes are known to fix nitrogen in a way that’s readily accessible for other plants. They often store excess nitrogen in their root nodules. When a plant is pruned, it sends those nutrients to the top of the plant and keeps accumulating more at the lower level, making other plants happy as well.

Low-lying plants like herbs are also common to see used in a chop and drop practice. They act as a “green mulch,” which serves the same purpose as more traditional mulchs. Not only are the new plants benefiting from protection from erosion and weather, but the herbs will also break down to provide extra nutrition over time.

Top 5 Plants for Chop and Drop

Here is a shortlist for plants to start you on your plant recycling journey.

1. Pigeon Pea – This quick-growing legume is the chop and drop classic. Many grow pigeon pea just for this purpose, as it produces a lot of biomass (leafy material) in a short amount of time. It also happens to be a legume whose roots are hard at work accumulating nitrogen that will live on after they are gone.

2. Moringa – It is everywhere these days, with good reason! Not only does it have numerous health benefits, moringa grows quickly, leaving an abundance of leafy material for you to harvest.

3. Nasturtiums – Speaking of green mulch, nasturtiums make for an especially attractive one. When planted with taller plants, they act as a natural barrier while alive, and when they die out during the hot months, they provide excellent biomass.

4. Lupine — Another legume, this one is an especially attractive addition to the garden that brings in the pollinators as well. Like the pigeon pea, lupine fixes nitrogen at the root level, which will be accessible even after the plant dies back.

5. Sunn Hemp — Valued for its stellar production, this friend of the soil accumulates biomass quickly and has the unique ability to suppress nematodes. In 90 days, sunn hemp can produce over 130 pounds of nitrogen per acre! While ideal for tropical climates, this might not be a great fit for northern climates.

BONUS: Lemon Grass – This may not be the first plant that comes to mind, but the biomass from one lemon grass plant is substantial! This makes lemongrass a great groundcover/green mulch option.

While these are some examples of plants that are ideal for the regenerative farming practice of chop and drop, just about any plant you prune and drop will be beneficial. Just one caveat: be sure that none of the material is showing signs of fungus or bugs, as these can be transmitted to other areas of the garden unintentionally.

Other than that, have fun and happy gardening!

Amanda Rose Newton holds degrees in Horticulture, Biochemistry, Entomology, and is currently finishing her PhD in STEM Education. Currently, she is a professor of Horticulture at Eastern Florida State College, Education Specialist at Rockledge Gardens, and all around insect enthusiast. When not working, she spends several weeks a year volunteering for USAIDs Farmer to Farmer program, promoting positive change in food security worldwide.