While colorful fall leaves are gorgeous and freshly picked fruit from various fruit trees is delicious, both can cause problems in your yard when they fall to the ground. So, while you often hear that mulching fallen leaves in the fall instead of raking is good for the soil and ecosystem, be sure to check the debris before choosing this approach. According to Susan Poizner, fruit tree expert and founder of Orchard People, leaving fallen fruit and leaves in the yard and garden can cause disease and attract unwanted pests.

“Fall leaves can be a good source of nutrients, but only if they are healthy,” says Poizner. “If they’re sick or infested with pests, you’re essentially giving those pests and disease spores a cozy place to overwinter,” she says. If left untreated, these pathogens and pests will multiply and return with a vengeance in the spring.

Learn how to spot fallen leaves affected by disease and pests, the best way to safely dispose of them, and how to prevent this from happening again in the future.

Inspect fallen leaves and fruit for disease.

“It’s helpful to become familiar with the common diseases that affect the types of trees on your property,” says Poizner. “When you recognize symptoms early, you can nip problems in the bud so they don’t spread.” Common diseases include fire blight, apple scab, rust, peach leaf curl, powdery mildew and bacterial canker.

When inspecting fallen leaves, look for signs such as spots or discoloration. “For example, orange spots on leaves often indicate rust, while olive-colored spots can be a sign of scab,” Poizner notes. “Wrinkled or misshapen leaves can be caused by peach leaves curling.”

Leaf spots are a good sign that the tree is infested. Almost all trees and shrubs are susceptible to one or more leaf spot diseases. Look for these clues:

• Spots that may vary in size and color. Depending on the specific disease and its stage, brown, tan, black, yellow, yellow-green, orange and red spots may appear.
• The spots are round or angular, raised or depressed, with smooth or fringed edges.
• Concentric rings or dark edges that enlarge over time and form spots. This is problematic.
• Premature leaf drop is a sign of some diseases.

Watch for pests around fallen fruit and leaves.

Fallen leaves can easily attract a variety of insects, rodents, and other pests to your yard because they provide convenient hiding places and nesting places. “Leaves that are webbed or curled can indicate pests,” Poizner says. She also explains how fallen fruit can quickly become a haven for pests. “If you notice fallen fruit with holes oozing mucus, this could be a sign that there are maggots inside.”

Some of the most common pests that are attracted to fallen leaves include:

• Beetles: Decaying leaves provide a source of food and a home for the beetles, as they thrive in confined, dark, warm, moist, and humid environments. While beetles are generally good for the garden, you may not want them to migrate into your home if your leaves are near the entrance.
• Termites: These pests often use fallen leaves as cover due to the cellulose they contain. As the leaves begin to decompose, they release an odor that attracts termites. Termites in a leaf pile can quickly spread to nearby woods, such as your home.
• Cockroaches: Because cockroaches seek warmth and moisture, they sometimes use fallen leaves for food and shelter during the colder months. However, they can easily infect your home.
• Spiders: Piles of leaves attract food-seeking arachnids, including black widow spiders, venomous predators that seek out smaller insects often found around leaves.
• Rodents: Beetles are an excellent source of protein for rodents such as mice and rats, so they often end up in leaf piles that already have beetles in them. In addition, rodents seek shelter when temperatures drop.
• Snakes: Just as rodents hang out in leaf piles to feed on bugs, snakes stalk rodents.

The problem is that rather than staying outside in the leaf pile, these pests may end up making their way into your home. That’s why it’s important to address the problem right away and not let piles of leaves build up for weeks or months.

Dispose of diseased or contaminated organic matter safely.

Prompt cleanup and disposal is essential to prevent further spread of disease. “Unless you’re very good at detecting and identifying disease symptoms, it’s best to play it safe and collect any organic matter around your fruit trees,” says Poizner. She recommends waiting for the leaves and fruit to fall to the ground naturally, then collecting everything together and sending it to a municipal leaf litter collection. “If we collect fallen leaves and fruit in the winter, we can interrupt the life cycle of pests and diseases and protect our trees without chemicals.” Place trash in sealed bags and closed trash cans.

Don’t put diseased leaves and contaminated fruit in your home compost, because these pathogens will just hide there, Poizner advises. “You need a huge hot pile of compost to kill pathogens and pests, but home composts are rarely that hot.” Indeed, composting infected plants is risky and difficult; The compost pile should be kept at a temperature of 140 to 160 degrees Fahrenheit and turned frequently. Even so, some viral diseases can still survive.

Another option is to bury the leaves. Some diseases can live in the soil for years, so bury waste as far away from the garden as possible, in an area that you do not plan to use for growing garden plants. Dig a hole 1 to 2 feet deep, fill it with plant debris, mix the soil, and then backfill with at least 2 inches of fresh, healthy soil. You can speed up their decomposition by shredding the leaves before burying them, but be sure to disinfect your equipment afterwards to prevent the disease from spreading to healthy trees and plants.

Avoid burning leaves, a dangerous and illegal practice in many places. A light breeze can spread burning material and start a destructive forest fire.

Don’t let these problems happen again next season.

To avoid future pests and diseases, take preventative measures such as keeping your yard clean and vegetation treated. “Fall cleaning is a great start. Harvest carefully—these leaves and fruits may contain pests and diseases that could infect your tree again next season,” says Poizner.

She also recommends using the sprayer in early spring, before the buds open. “I use a mixture of oils with lime sulfur, which is effective, but not the only option. The oil in this mixture coats the branches and bark (be sure to spray it into cracks and crevices), suppressing insects that overwinter on your tree.” This can prevent many pest problems during the growing season. Just be sure to read the instructions carefully; applying it at the wrong time or to the wrong tree can do more harm than good.

She also suggests pruning annually to protect trees from disease, as this allows the tree to have better air circulation and sunlight penetration. “This prevents the dark, damp conditions that pests and disease spores love,” Poizner says.