Mulch has tons of benefits—we’ll get to those—but probably the one homeowners appreciate the most is how it tidies up the garden. Spreading mulch is a lot like raking leaves–it’s an endless job when you’re in the middle of it, but the result is so gratifying. Who doesn’t love that clean, weedless, dark brown/black color as a backdrop for spring when it arrives? It’s not July when the garden is overrun with weeds, plants, and humidity. It’s January, and the garden is still in our control, so mulching the garden now avoids the obstacle course of the emerging garden.
Mulch isn’t just decorative, though. It benefits the garden’s health. Here’s how.
Mulching the Garden to Control Weeds (Mostly)
Before we get all happy about that, let’s qualify. Mulch suppresses weeds. It suppresses weeds. Mulch does not get rid of weeds. Instead, it is one of the components of the weed war. So yes, you’ll still be pulling weeds in your beds, but a good pre-emergent and a 2″ layer of mulch go a long way to reducing the weed population in your beds.
Weeds are competitors in the garden, drawing vital nutrients and water away from garden plants. Eliminating weeds isn’t the goal (read here for why some weeds are beneficial) but minimizing the competition and keeping the messiness in check is.
Mulching the garden helps regulate soil temperatures in extreme bouts of heat and cold and helps retain water during hot and dry seasons. Again, notice it helps. Mulch isn’t the cure; it’s the supplement. The gardener still has work to do, but mulch is hugely helpful in fighting against weeds and keeping plants hydrated.
And, as noted above, it is decorative. It can tidy up the place. Our Landscape Designers and Garden Coaches are frequently asked to help with curb appeal when folks sell their homes. Cleaning up beds and spreading mulch adds appeal quickly and is often all that’s needed.
Mulching the Garden With What?
Mulch is any material used to cover up the surface of a planting bed. It can be organic or inorganic. There are advantages and disadvantages to both.
Examples of Organic Mulches Include:
- Shredded Bark
- Pine Straw
- Wood Chips (often dyed in different colors)
- Peat Moss
- Groundcovers or living mulches
Examples of Inorganic Mulches Include:
- Cobble Rock
- Decorative Gravel
- Pea Gravel
Advantages of Organic Mulches:
- Reduce soil moisture loss
- Decomposition can add nutrients to the soil
- Decomposition can alter soil pH
- Benefits overall plant health
- Moderates soil temperatures (hot or cold)
- No mowing hazards
- Discourage weed growth
Advantages of Inorganic Mulches:
- Reduce soil moisture loss
- No decomposition
- Rarely need replacement
Discourage weed growth
Disadvantages of Organic Mulches:
- Potentially flammable in high heat conditions
- Require replacement due to decomposition
- Dyed mulches can get on clothing, animals, and paved areas
Disadvantages of Inorganic Mulches:
- It does not affect soil pH, nutrients, or soil nutrition
- Potential mowing hazard (can be thrown at people, windows, and cars)
- It may retain heat and harm plants in warmer areas
- Children love to throw it into the yard
Mulching the Garden: When and How Much?
Mulching the garden in late winter/early spring before the perennials show up and covering beds is easier. You aren’t stepping on delicate perennial sprouts or covering them with mulch.
Two to three inches is the maximum amount to layer mulch—-two inches being optimal. More mulch isn’t the answer to your weeds and watering. Too much mulch can harm plants. See the above picture? That is the WRONG way to mulch. Keep the mulch at least 3″ away from the trunks of your plants because it can suffocate plants if it is too high up the trunk.
You should always see the root flair on your trees and shrubs. Again, more is not beneficial, and mulch is part of the solution, not the answer. Piling up the mulch and then creating a well for water isn’t the solution either. Refer to the picture below.
Spread mulch using a pitchfork, then rake it with a stiff rake or spread it evenly with your hands. Avoid piles in one place and not enough in another. Even distribution is what you’re going for.
Mulching the Garden: Groundcovers as Mulch
Sometimes it’s about planting, not spreading mulch. Groundcovers can be ground-hugging or taller, like a hosta. Hostas are good weed suppressors with their large leaves and low-growing habits, so when thinking about mulches, don’t forget the plants. Many ground-covering plants help keep weeds at bay and retain water. For more information on this, here’s a blog on using groundcovers instead of traditional mulches.
Written by Cinthia Milner, Landscape Consultant and blog writer.
B.B. Barns Garden Center serves Western North Carolina, upstate South Carolina, and Tennessee.