Applying mulch every spring makes sense on several levels. It helps enrich the soil and helps retain moisture during the dry summer months. But the main reason most of us mulch is weed control. Every time, we put down a couple of inches of mulch and hope that we’ve won the battle. Unfortunately, most of us aren’t that lucky. Weeds will almost always find a way to grow, even in the most beautifully mulched yards. What makes weeds so tough to control, and how can you stop them?
Mulching is a key practice for any garden, providing vital benefits like moisture retention, temperature moderation, and weed suppression. But before you start mulching, an important question arises – do you need to weed first?
The short answer is yes – it’s best to weed thoroughly before applying fresh mulch However, the reasons why involve some nuances In this complete guide, we’ll dig into the details on pre-mulching weeding, including
- Why weeding beforehand is so important
- Tips for effective weeding prior to mulching
- What to do if you’ve already mulched over weeds
- When weeding may not be necessary
- Alternatives that reduce pre-mulching weeding
Read on to get the complete lowdown on whether and how to weed before mulching your garden and landscape beds.
Why Weeding First Is Critical
Weeding before laying down mulch serves two key purposes:
1. Allows the mulch to work most effectively
A fresh layer of weed-free mulch forms a uniform barrier that blocks light, preventing weed seeds in the soil below from germinating. But weeds that are already growing will simply continue to push up through the mulch unless removed first.
2. Prevents weeds from getting a foothold
Mulch provides ideal conditions for weeds by holding in moisture and offering a fertile growing medium. Any weeds left in place quickly exploit those conditions, growing stronger and faster. And weeds left to flourish under mulch will drop far more seeds, leading to bigger future problems.
That’s why weed removal must be thorough before mulching. Even small young weeds left behind may survive and multiply in the favorable mulch environment Taking time to weed carefully prevents much bigger headaches later on
Tips for Effective Pre-Mulching Weeding
To maximize the weed prevention power of mulch follow these tips when weeding prior to application
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Inspect beds closely for any vegetative growth. Check under shrubs and perennials too.
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Remove weeds completely, including all roots if possible.
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Rake up and dispose of any weed debris so it doesn’t replant itself.
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Use a hoe to gently disturb the top 1-2 inches of soil to reveal any hidden weeds.
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For lawns, remove weeds up to the bed or border edge. Don’t let grass creep under.
Thorough weeding sets your mulch up for the best chance of keeping weeds away. Expect to periodically hand-pull any weeds that eventually emerge. But pre-mulching removal limits their numbers.
What If You’ve Already Mulched Over Weeds?
The best remedy for weeds that sneak through mulch is to pull them immediately if possible. Otherwise:
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Carefully pull back the mulch in affected areas.
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Remove any visible weeds, roots and all.
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Stir up the top inch of soil to unearth hidden sprouts.
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Reapply the mulch, creating an even layer with good coverage.
This simple maintenance preserves the weed-blocking capacity of your existing mulch. Letting weeds persist leads to loss of control and a major re-do.
When Weeding May Not Be Necessary
In reality, pre-mulching weeding is rarely 100% perfect. But there are cases where you can reasonably skip more weeding:
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Re-mulching existing beds yearly with minimal new weed growth. Stirring the mulch to remove sprouts may suffice.
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Using inorganic mulches like gravel that block light and don’t facilitate weed growth. Still remove existing weeds.
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Applying mulch that contains pre-emergent weed killers, like Preen Mulch with Extended Control. It prevents weeds even if remnants exist.
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Mulching over drought-stressed lawns or pastures that have completed their life cycle and left bare soil. Few live weeds remain.
Discretion is key – if weeds prevail in these cases, take the time to remove them for best results. Otherwise mulching over is acceptable. Evaluate each situation based on current weed pressure.
Smart Alternatives to Weeding First
Other options exist if thorough pre-mulching weeding sounds daunting:
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Sheet mulching – Layer cardboard or newspaper over weeds before mulching. The sheets smother out growth underneath.
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Solarizing – Cover the area with clear plastic for several hot weeks. The “greenhouse effect” kills weeds before mulching.
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Flaming – Use a propane-powered weed flamer to incinerate weeds and roots prior to mulching.
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Grazing – For large spaces, let livestock like goats or chickens graze weeds down before applying mulch.
Each offers an ecological, labor-saving alternative to hand-weeding or herbicides. Optimal weed control still requires vigilance, but a bit less back-breaking weeding.
How Can I Prevent Weeds in My Mulch?
Here are a few strategies for preventing weeds from popping up in your mulch:
- Apply the right amount. Blocking weeds from getting the sunlight they need to grow is what mulch is mostly used for. To make this work, you need to make sure it’s thick enough: we suggest 1 5 to 2 inches. But don’t use too much mulch, or your plants won’t get enough air.
- Weed first, then mulch. As you get your bed ready, remove any old mulch and pull out any weeds. Then, add a layer of new mulch.
- Treat the soil with a pre-emergent herbicide before mulching.
- Sometimes, like around trees and shrubs, you can put down landscape fabric first instead of mulch. The soil can get air and water through it, but weeds can’t grow.
- Putting edging around your mulched beds can also keep stray seeds from getting stuck in the mulch.
Why Do Weeds Grow In Mulch?
We all know how tenacious weeds can be. They thrive on the very same things your garden does: sunlight, water, and nutrients in the soil. Weeds take pretty much any opportunity to grow and aren’t picky about where they take root. As plant-based mulch decomposes, it provides an attractive, nutrient-rich environment for weeds to take root.
We often find weed seeds in old or contaminated mulch. Seeds can also get distributed by birds or wind into new beds.
How To Keep Weeds Out Of Mulch
FAQ
Can I just put mulch over weeds?
Do I need to remove dead weeds before mulching?
Do you need to put anything down before mulch?
Do you need weed fabric under mulch?
Do I need to weed before mulching?
Planting a newly made bed. You may not need to weed before mulching, depending on what the “now” garden bed was before. i.e., if there was a cover of sorts on the ground, cement, a building, or grass that was clearedto make room for a new bed, weeding may be unnecessary.
Should I mulch before or after planting?
Mulch can be applied either before or after soil preparation of new beds. Some pros prefer to mulch the entire bed free of plants ahead of time, and then make holes for the plantings, being sure to pull away excess mulch from the crowns. Others prefer to plant first and then mulch around them. Applying Preen Garden Weed Preventer.
Does mulch reduce weed growth?
When used correctly, mulch can reduce weed growth, moderate soil temperature, and slow the evaporation of water. Here’s a few things to remember before you get spreading: Use an edging tool to cut a sharp edge around garden beds before mulching.
Does mulch kill weeds?
While a good layer of mulch can smother small, young weeds, don’t expect it to magically eliminate well-established weeds. It’s better to remove any big weeds and patches of weeds before mulching over them, or they’ll pop right through. Or, as noted in the previous tip, some may keep on spreading under your mulch. 6. Don’t Use Too Much Mulch
Should you put woody mulch in a vegetable garden?
“For a vegetable garden, cheap compost does a much better job of mulching than expensive decorative woody mulch. And it feeds the soil,” says Baka. A layer of woody mulch also makes it harder to quickly hoe weeds from between your rows, Baka adds, noting that you must remove it first, weed it, and then put the mulch back. 3. Avoid Fresh Mulches
Can you put weed seeds under mulch?
“Let fresh mulch sit a few months to leach out any residue and let weed seeds sprout and die,” he advises. Composting it before use is even better. 4. Watch out for Creeping Plants Plants that spread by creeping stems, particularly turf grasses such as Bermuda grass, are sometimes so vigorous that they’ll grow right under mulch.