Why You Should Always Pull Dead Plants from the Garden

If you wonder whether you should leave dead plants in the garden, the answer is yes. Pulling dead plants that carry pests or diseases—which, unfortunately, applies to many crops—is key to preventing future problems.

But, leaving certain dead plant material in place also enriches the soil and creates a habitat for beneficial insects—so there are some exceptions. 

Read on to learn which plants you should pull and which ones you can leave standing.

Why You Should Pull Dead Vegetable Plants

There are two compelling reasons why dead plants should be pulled.

Pests and Diseases

When a plant gets hit by a pest and/or disease, it needs to be pulled. Some diseases, such as tomato blights, are so persistent that you must dispose of infected plants in the trash.

But even less severe diseases such as powdery mildew overwinter on plants and pose a risk for next season’s crops, and the same applies to pests.

To break the cycle, you should pull all plants that are especially susceptible to pests and diseases, such as members of the nightshade family (tomatoes, eggplants, potatoes, peppers), brassicas (broccoli and cabbage), and cucurbits (cucumbers, winter and summer squash, melons) once the harvest is over. 

Crop Rotation

The other reason why plants should be removed from the garden is that they tend to reseed themselves in the same location.

Tomatoes are notorious for that—you’ll end up with oodles of tomato seedlings in the same spot the next year, but if the tomato is not an open-pollinated heirloom variety and is a hybrid, the tomatoes won’t have the same qualities as those from the parent plant. So, they will likely taste disappointing.

This is a big no-no—crops must be rotated every year to prevent pests and diseases and avoid unilateral nutrient depletion of the soil.

Want more gardening tips? Sign up for our free gardening newsletter for our best-growing tips, troubleshooting hacks, and more!

Which Dead Plants Actually Enrich Soil?

There is no harm in leaving some dead plants in the garden if they are not contaminated by pests and diseases and won’t reseed. Just dig them under to speed up the decomposition.

The best plants, however, to benefit your garden soil are cover crops, also called green manure. Planted as soon as the summer crops have been pulled, cover crop seeds germinate quickly and grow during the fall and winter before being dug under in the spring.

Cover crops roughly fall into three groups:

• Grains such as winter rye
• Legumes, such as clover
• Broadleaf plants, such as buckwheat.

Cover crops require extra effort, but they are worth it—they add valuable biomass to the soil, keep weeds out, and aerate the soil.

Benefits of Dead Plants for Wildlife

When it comes to the other plants in your yard, consider skipping a thorough fall cleanup where you indiscriminately cut back all the plants.

Only cut back plants that are diseased, such as peonies, which tend to be covered with powdery mildew at the end of the season. By cutting them back and disposing of the diseased foliage in the trash, you remove the spores from your yard.

Likewise, collect debris around trees and shrubs with pest or disease issues and remove all fallen fruit from around fruit trees—but leave all the other plants untouched.

The more beneficial insects you encourage to stay in your yard over the winter, the better your garden will do the next season.

• The seed heads of annuals such as sunflowers and many perennials provide food and shelter for birds and other wildlife.
• The hollow or pithy stems of tall perennials such as bee balm serve as a hibernating and nesting space for cavity-nesting bees and other pollinators the next spring.
• Ladybugs, which are important predators of aphids, overwinter in leaf litter and other protected spaces.