The Best Fertilizer for Any Plant is… its Own Foliage

When fall comes around, many gardeners get itchy fingers. They want to get out and do a thorough fall cleaning. I’m not saying there isn’t a bit of cleanup to do in the fall, but there’s a very important detail about gardening that is often misunderstood or totally ignored: the fact that the best fertilizer for any plant is its own foliage.

Leaves Rich in Minerals

Indeed, the leaves of a plant contain nearly all the minerals it needs for its future growth, and in the right proportions too. When you cut back and pick up a plant’s dying or dead leaves in the fall and put them in the compost pile or worse, throw them out with the trash (what a waste!), you’re depleting the soil in which it grows.

Different plants have different strategies for how to preserve the minerals found in their leaves for upcoming season.

Most perennials hold on to their old leaves. They collapse to the ground in late fall, but remain attached to the crown of the plant via their petioles as they decompose over the winter. Thus, when the plant wakes up in the spring, you can still see what remains of its old leaves splayed out all around it, surrounding the new shoots as they appear. As the leaves decompose and disappear, they’re already feeding the roots of the mother plant.

Trees and shrubs have a different strategy: they drop their leaves in the fall, thus creating a layer of dead leaves covering their entire root zone: a natural and rich mulch called leaf litter! The leaves decompose slowly throughout the summer, nourishing the roots below.

Conifers generally retain their needles for 2 to 5 years (only one season for larches, but up to 40 years for bristlecone pines!), but their leaves do drop eventually… and cover their root zone. Needles decompose more slowly than broad leaves and can take several years to disappear entirely, but even so, they do slowly release the minerals the tree above needs.

Harming Plants We Think We’re Helping

When you cut your perennials to the ground in the fall and carry their leaves to the compost, and when you pick up tree leaves to put them out for the municipality to deal with them, you’re actually harming the future growth of your plants, because you’re impoverishing the soil. To compensate, you have to purchase and apply fertilizer. Unfortunately, most fertilizers dissolve far more quickly than the plants can use them, and thus many of the minerals they contain end up polluting lakes, rivers, and groundwater. Plus you need to fertilize again and again to make sure the plants plants get the minerals they need.

Why not let Mother Nature take care of feeding your plants instead? Letting the leaves decompose where they fall is less expensive, requires less effort and doesn’t pollute! And since the best fertilizer for any plant is its own foliage, their decomposition continues at exactly the rate the plant needs to grow well.

It’s the same for the lawns: when you mow, leave the clippings where they fall and they’ll decompose and enrich the soil. Again, as with other plants, the best fertilizer for turf grasses is their own foliage.

Learn to Trust Mother Nature

Many gardeners are afraid to let Mother Nature do the work. They imagine that dying fall foliage will stay put or even accumulate and thus negatively affect the appearance of their lot and that they’ll still have to do a major cleanup in the spring when the leaves are soggy and unpleasant to work with. But why not try doing no fall cleanup at all? You’ll soon see: most of the leaves will be already nearly decomposed by spring (and will disappear entirely during the summer) and those that remain will make a great and quite attractive mulch, and we all know that mulch is good for plants. True enough, you’re bound to find a few stalks still standing in the spring that you may want to remove (you can just cut them off and lay them on the ground so they can decompose), but that’s still much, much less work than all that cutting and bagging in the fall!

Of course, I’m not saying you can’t add a bit of organic fertilizer every now and then to give your gardens, trees and lawn an extra boost… but they can certainly get by on what Mother Nature provides, if you let her do her job that is: they’ve been doing so for millions of years!

I repeat: the best fertilizer for any plant is its own foliage. When you understand that, and how to take advantage of this benefit, you’ll become a better gardener… and a more ecological one as well!