WINCHESTER — Haven’t gotten round to your fall garden cleanup yet?

Good! Think of yourself as an environmentalist.

Most of us do far too much garden tidying in the fall. It’s actually better both for your garden and the environment to leave much of the ‘’debris’’ alone until spring.

Wild animals, including birds, have very little to eat over the winter, and their primary diet is seed based. It’s pretty well known that sunflower heads left over the winter help the birds, but so do seed heads from smaller flowers. Native perennials like coneflowers are particularly appealing to our cold and hungry avian friends.

Dried plants in your borders also provide essential shelter for wildlife in winter, both in terms of warmth and safety from predators. Clumps of tall ornamental grasses offer humans visual interest, while beneficial insects like butterflies and lacewings hunker down inside. Toads, the best garden pest control experts you’ll ever find, build winter burrows under piles of garden ‘’litter.’’

But what about all those leaves? They’re good too, especially for your garden. A layer of leaves insulates the ground and the plant roots from extreme temperatures. As it breaks down, it adds vital nutrients to your soil. Both leaf mulch and leaf compost are highly sought after in garden centers; your trees are kindly depositing them for free.

If you have the time and energy, run larger leaves over with the mower, as smaller pieces decompose faster. My platter-sized sycamore leaves were pretty much still intact this spring, though at least they had formed a nice insulating blanket over the winter. In March, rake up any remaining leaves and add them to the compost pile. They’ll break down quickly in warmer temperatures next spring and summer. Don’t compost or mulch with walnut leaves, though, as they can be toxic to other plants.

Leaves littering driveways and paths can be cleared now and added to the compost heap, or they can be used to mulch garden beds for the winter. They’re also good insulation for delicate bushes. Some of my hydrangeas suffer from winter dieback when left to fend for themselves, but this year I’ll protect them with tomato cages stuffed full of leaves.

So should you just walk away from the garden this fall without doing any clean-up at all? Well, no. The exception to the policy of laissez-faire is diseased or blighted plant matter. This includes debris from fruit trees affected by fire blight or apple rust, blighted peony leaves and tomato plants, squash vines hit by borers or squash bugs, etc. Remove all of that as soon as possible and dispose of it in the trash, not the compost. Otherwise, let it rot.