Eco-Answers from the Pros: Mulched Leaves and Drought

How are you using chopped or composted leaves to mitigate the effects of drought? How effective have your strategies been?

Our company first started using leaf mold mulch at the request of our clients; they were plant collectors, who used pesticides and fertilizers only as a last resort.  Most of the time, they were letting Mother Nature work her magic, only intervening to correct pH, or in the case of the leaf mulch – to correct for the lack of snow cover during “open winters” (when the ground is not covered in an insulating blanket of snow that their plants needed). Similar to the way grass clippings when left on lawns, leaf mulch keeps the nutrients in the leaves on the site, rather than taking them away and then having to replace them with fertilizers.

These clients were firm believers, as I am now, that the leaves are truly nature’s bounty. Leaves are full of nutrients (80%) that trees, plants and beneficial soil biology need. Due to their relatively fragile nature – they break down faster than heavier coarser mulches and are more readily “plant available” than ubiquitous shredded or chipped wood mulches. They provide the additional services of alleviating moisture loss, moderating temperature extremes, and preventing erosion. In addition, the leaves (even if somewhat over-applied) would not smother or destroy plant crowns the way that the shredded wood mulches do.

We shared information about equipment to use and the most efficient way of collect, shred and re-spread the mulch all over the property. In all instances, the clients were reluctant to use commercially supplied leaf mold mulch as they didn’t really know what had been applied to the properties that those leaves were supplied from. So we produced it ourselves. We first used the electric hoppers, then the electric blower/vacuum machines, and finally we started using a mower when we realized that in any larger shredded leaves that remained could be pulled off the beds (if they interfered with the plant’s growth). However, in most circumstances the leaves were a reasonable mix of finely ground to halved or quartered leaves that mimicked forest floor duff layers. Larger coarser pieces of shredded leaves do a better job at alleviating soil temperature extremes, so a happy medium has become one of our goals.

The mower has greatly speeded up our process. If we need the leaf size more finely ground, we windrow the piles and then double mow them. Depending on the property and what is planted where, we can actually mow in place and leave the shredded leaves where they land in the beds. Care is taken to avoid leaving too much material on the beds and to avoid smothering evergreen material.

We usually return in the spring and repeat the process. If we are lucky, we do this before the bulbs are up, so we are not stepping on delicate plant material and breaking it. In most cases, the seemingly vast quantities of fall leaves get used up in the final mid-late summer touch up to keep the ground covered during droughts. Occasionally, we have extra leaves that get held over, but lately, with the changing climate and the extreme cold of the open winters, we have depleted our stockpiles on our properties just in time for the new cycle of harvesting and shredding.

We, like our clients, feel that using leaves as mulch is saving them money in the long run, as we are combining several functions all at the same time (leaf clean-up, mulch, and fertilizer applications). In most instances, clients who originally thought they wouldn’t like the look, discovered that leaves were generally the same color as conventional mulch and that it functioned similarly or better than traditional mulch.

Cathy Rooney owns and operates Designer Of Greens, a full service landscape design, install, and maintenance company that introduces ecological concepts and habitat gardens to clients. We do small gardens, Containers, pollinator landscapes, renovations and restoration, Invasive plant management, permeable patios, fire pits, and outdoor kitchens. Cathy may be reached at (508-561-0532).

ELA members have spent hundreds of hours learning the best ecological solutions to problems in the landscape. You can benefit from all that accumulated knowledge by posing a question to our experts. If you are stumped by a problem in your landscape or are looking for a second opinion on a potential solution, ask ELA’s Eco-Pros. Send your question to ela_new@verizon.net. And if you need additional help, refer to the listing of ELA Professionals.

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