Spring Mulching: Timing, Depth, and Why More Isn't Better

Fresh mulch is one of the fastest, highest-impact things you can do for a property's curb appeal each spring — but there's a right way and a wrong way to do it, and "more is better" is one of the most common mistakes homeowners make.

When to Actually Put Mulch Down

The best window in Central Illinois is after the ground has warmed up in spring but before summer heat sets in — generally sometime in April, once the risk of hard freezes has mostly passed. Mulching too early, while soil is still cold and wet, can trap moisture against plant crowns and roots and actually encourage rot rather than protect against it.

Why Piling It Deep Backfires

A common mistake is piling mulch several inches deep, especially right up against tree trunks and shrub bases (the "mulch volcano" look). Too much mulch holds excess moisture against bark and stems, which invites rot and disease, and can suffocate roots that need to breathe. Two to three inches is the right depth for most beds — enough to suppress weeds and hold moisture, not so much that it works against the plants it's supposed to protect.

What Good Mulch Actually Does

Done right, mulch regulates soil temperature, holds moisture so beds need less watering through summer, and suppresses weed germination by blocking light to the soil surface. It also breaks down over time and adds organic matter back into the soil, which is part of why refreshing it annually (rather than piling new mulch on top of old, compacted mulch every year) keeps beds healthier long-term.

The Bottom Line

Mulching is simple in concept but easy to get wrong — the right timing and the right depth make the difference between mulch that helps your plants and mulch that quietly works against them.