As autumn leaves fall, they offer an economic and ecological resource for gardeners willing to collect and reuse them. According to Michael Jesiolowski, manager of the Plant Clinic at The Morton Arboretum in Lisle, gathering leaves provides a free source of mulch, insulation, and fertilizer that benefits gardens throughout the winter and beyond.

Leaves play a vital role in natural soil formation and health. When leaves and dead plant material decompose, soil fungi, bacteria, and other organisms break them down into humus, enriching the soil and releasing essential nutrients. This decomposition process improves soil structure by enhancing its capacity to hold moisture and nutrients, ultimately fostering healthier plant roots.

Gardeners can apply fallen leaves as mulch by spreading them around perennial beds, trees, shrubs, and vegetable gardens. Leaves placed in these areas gradually decompose and support soil organisms, enhancing soil quality over time. Jesiolowski advises raking most leaves off lawns to prevent thick mats that block sunlight and trap moisture, potentially encouraging disease. However, leaving a light layer or shredded leaves on grass can help improve soil health for turf.

Shredding leaves accelerates breakdown and keeps them from blowing away, making them more manageable for use as mulch or compost. A simple method is to run a lawn mower over leaves piled on the grass, then collecting the shredded material for garden use.

Leaves also serve as a valuable ingredient in compost piles. As a carbon-rich "brown" material, dried leaves balance the "green" components such as vegetable scraps, end-of-season plants, and even broken pumpkins. Composting these materials produces a nutrient-rich soil amendment after several months.

Additionally, leaves offer insulation benefits. Covering late-season vegetables like cabbage or spinach with a layer of leaves can protect them from early frost. Leaf mulches over root crops such as carrots and beets slow soil freezing, extending harvesting time into winter.

In terms of soil improvement, adding organic matter such as shredded leaves or compost can enhance soil texture. This is beneficial across different soil types, helping clay soils loosen and sandy soils retain moisture. Gardeners can incorporate these materials by tilling them into new beds or spreading them atop established planting areas.

Storing leaves for future use is encouraged. Leaves can be kept in dedicated compost bins or designated garden corners and shredded to save space. This practice ensures a steady supply of organic material throughout the gardening season.

For additional gardening and plant care advice, the Plant Clinic at The Morton Arboretum is available to assist.