I’ve been mulching for decades now and find it helps give me healthy plants with less work on my part: less watering, less weeding, less fertilizing, etc. I usually just use good ol’ shredded leaves, free and easy to apply.
However, I never “pull back the mulch from around the base of the plants” nor leave “6 inches of soil bare around each plant,” a bit of advice you see almost universally when you read texts on mulching. I just apply mulch evenly right up to the base of the plants I grow and I’ve never had a problem with it.
Besides, one of my reasons for applying mulch is to reduce weeds, and leaving a bare spot around each plant is an open invitation for weeds to set up shop!
Not that I create “mulch volcanoes,” that is, where you pile mulch up to 1 foot thick or more at the base of a tree, as that could seriously reduce air circulation at the tree’s base, but I do use mulch pretty thickly. Up to 4 inches thick. That’s because the chopped leaf mulch I apply decomposes very quickly, so if I want a 2-inch coverage in early summer, when weed seeds are starting to sprout, I need to add 4 inches of mulch in the fall when leaves are available.
Why “Pull Back” Mulch
Theoretically, this is:
- To help the plants “breathe.” No kidding: you do actually read that! But very little if any “breathing” is going on at the base of a plant’s stem. Plants mostly breathe through their leaves and roots.
- To reduce insect/animal attacks. But they aren’t many stem-attacking insects that live in mulch. I can’t even think of one! Under the mulch, maybe (cutworms, for example), but in the mulch?
Of course, you could make the argument that voles, who love to gnaw bark during the winter, could use the cover of mulch as a pathway to tree and shrub bases. My experience is, however, that in those bad vole winters, pretty much every thin-barked tree and shrub gets whacked, whether you use mulch or not. And the damage is always above the mulch.
- To help prevent rot. This is the main one. The idea is that mulch retains moisture and moisture can cause rot. That would appear to make sense … but have you ever actually seen it happen? I haven’t, and I live in a very rainy, very humid climate. About 46 inches of precipitation per year, which is more than Seattle or Vancouver, both in areas considered “rainforests.”
Of course, it’s not moisture that causes rot but rather fungi or fungus-like organisms (Phytophthora spp., which are oomycetes, are the best known) and fungi and their friends thrive under moist airless conditions. Mulch is, by definition, well aerated. Just try handling it and you’ll see. It’s much lighter and aerated than soil, for example: you can see the air spaces. It may hold water, but it lets air circulate. Abundantly.
I try to use mulch like Mother Nature does, spreading it evenly right up to the base of plants. There are no little gnomes pushing leaf litter (the most visible natural mulch) back away from the base of forest plants and trees, for example.
Here’s what I’m finding.
Mulching right up to the base of woody stems (trees, shrubs, some climbers, etc.) does not cause rot, nor do the plants root into the mulch (something some gardeners claim can happen).
Perennials, bulbs and other plants that die to the ground in the fall just push right back up through mulch come spring, as they would grow up through leaf litter in the forest. I don’t mulch very low-growing perennials (say, creeping thyme or Irish moss), as mulch would cover their leaves and prevent photosynthesis, but I do mulch all the others.
Annuals and biennials don’t at all mind mulch while they’re growing, but won’t self-sow in my mulched beds. I have to leave bare spots near the mother plant if I want to ensure they come back. (Not all annuals self-sow, of course, even if you don’t use mulch, but most biennials will do so if given the chance.)
I mulch my vegetable bed, planting right through the mulch when it comes to transplants (tomatoes, peppers, etc.). I pull back the mulch when I sow vegetable seeds, then push it back into place when they’ve grown taller than the mulch. No rot there either.
Do what you want. Toe the “pull mulch back” line or ignore it. I ignore it … and have been getting great results for decades!