Q: My church has planted 76 trees over the past7 years. Now we have more than 200 trees on 7 acres of land.
After an initial mulching by the landscaper, we have been applying mulch ourselves.For aesthetic reasons, we plan to continue mulching the trees near the church building, but we would like to stop mulching the rest of the trees. How many years should we keep applying mulch before the trees can survive without the mulch?
A: That's some good stewardship in re-treeing land that so often gets left in gas-, time- and resource-sucking oceans of lawn.
Your game plan sounds like a good one, and after 7 years to establish, now should be fine to cut back on mulching.
Mulch does a good job of holding down weeds, retaining soil moisture and making an area "look neat" to most eyes, so it's generally worth the effort around the most visible areas.
However, supplemental mulch isn't necessary for tree survival or even good tree health. Once trees are established, they're usually fine on their own. They even make their own mulch.
That's one of the beauties of trees. They're good at sustaining themselves by mining moisture and nutrients out of the soil to grow leaves and branches, then dropping the leaves, twigs, etc. to create a rough mulch.
As worms, weather, insects and soil microbes go to work on the fallen tree parts, it eventually breaks into compost and soil that in turn feeds the roots to keep the cycle going.
The main thing I'd watch for when you stop mulching trees is for the possibility of weeds and invasive plants to elbow their way in. That's more likely to happen early on before the trees mature.
Once invaders like poison ivy, mile-a-minute weed and Japanese honeysuckle get a leg up, they can take over an area pretty quickly. A good strategy is to do a periodic patrol to yank any brewing weed problem before it gets going.
Eventually, the combination of shade from a thickening tree canopy and increased self-mulching from the trees will make weeds less of a threat.
I tell doubters to look to forests for reassurance; nobody mulched them and those trees are growing just fine...