Every living thing in our gardens came from the wild somewhere. A few plants might be natives trying to adapt to synthetic landscapes. Some might be from similar climates. Some are likely from very different climates. Even houseplants came from the wild somewhere in the World. Regardless of their respective origins, in home gardens, all plants want to behave as they would in the wild.

Many plants want to defoliate at this time of year. Even some evergreens want to shed some of their old foliage before winter. Some perennials die back to the ground. Most summer annuals are already dead. There is an abundance of deteriorating organic material getting discarded by the plants that produce it. In the wild, all this detritus would naturally fall to the ground and decompose.

That might be a problem in parts of our refined landscapes. Fallen leaves must be raked from lawns, decks, pavement and various other flat spaces outside. If left too long, they shade out lawns, ground cover and bedding plans. Fallen leaves can stain decking and pavement too. The worst diseases of roses and fruit trees overwinter in fallen infected debris that does not get raked away.

Unfortunately, raking the mess of autumn away deprives the plants that live in the garden of the abundant decomposing organic matter that they expect to be delivered this time of year. The soil is left exposed and uninsulated, allowing temperature and moisture content to fluctuate more than they would naturally. Nutrients are not replenished as readily as they would be from decomposition.

Mulch, which can be applied at any time of the year, is quite seasonably appropriate in autumn. This is when plants expect decomposing organic matter to arrive from above. Mulch compensates for the loss of what we consider to be a mess, but what plants consider to be an important component to their natural ecology. It gives them what they want, but is neat enough for refined gardens.

The best mulch for the job just might be fallen leaves that were raked last year and composted, perhaps with other debris from the kitchen and garden.

It is silly for us to think that we know more about gardening that the plants who live out in the garden full time. We can help them along by giving them a bit more of what they need to survive, such as water and fertilizer. We can prune them to help them concentrate their resources into bloom and fruit production. Through it all though, we really need to be observant of what they do naturally.

For example, we water many plants through dry summer and autumn weather because we know that they are naturally endemic to climates that provide a bit of rain throughout the year, and that they can get dry without it. We fertilize them when they are actively growing because we know that is when they want it. Most deciduous plants get pruned in winter because they are dormant then.

This time of year, deciduous plants are defoliating in a very obvious manner. Evergreen plants are more subtle about shedding some of their foliage. Defoliation and shedding happens this time of year because plants do not need so much foliage, if any, when there is not so much sunlight for foliage to exploit. The days are shorter, and the sun is at a lower angle, so sunlight is less direct.

There are other reasons why winter defoliation is sensible. It makes deciduous plants more aerodynamic, and less likely to be damaged or blown down than they would be if they kept their foliage for wintery winds to blow against. Likewise, when the weather gets frosty, defoliated deciduous plants leave little to get ruined. What does all this suggest for seasonal garden chores for autumn?

Mulch, which can be spread at any time, is particularly timely for autumn, because that is when the garden expects organic material from above. Just like fallen leaves would do in the wild, mulch settles in through rainy winter weather, and helps to retain moisture after the rain stops next spring. It inhibits weeds that will want to grow as soon as the rain starts, and insulates perennials that grow slower or go dormant when the weather gets cooler. Mulch helps an unnaturally cultivated garden do what it wants to do naturally.