Mulch to Control Weeds and Save Water | Almanac.com

Mulch to Control Weeds and Save Water


Mulch Your Garden to Beat the Heat

The Editors

We’ll show you how to properly mulch in hot summer months to keep plants moist and suppress weeds. Mulch your garden to beat the heat!

Use Mulch to Reduce Weeds, Save Water & Feed Your Plants

Crops need three things to grow strongly: weeding, watering, and feeding. An organic mulch will help you to do all of the above, with the following advantages:

  • Reduced weeding. Mulches prevent light from reaching the soil, reducing weed growth and saving you lots of work!
  • Protected soil. Severe weather can result in compaction and erosion of bare soil.
  • Moisture retention. Mulching moist soil helps prevent evaporation and keeps soil moist for longer.
  • Improved soil. Organic mulches improve soil structure, and they contain nutrients which feed the soil as they rot down.
  • Natural pest control. Mulches provide habitat for beneficial pest predators such as ground beetles.

Mulching is a great way to use up grass clippings and shredded prunings. They can be used on the vegetable garden or around fruit trees and bushes. Shredded prunings and shredded bark also make excellent path surfaces between beds.

Straw or hay can be used to help keep fruits such strawberries, zucchinis and bush tomatoes dry and up off the ground. This protects the developing fruits from rotting.

Mulching Techniques

  • Don’t lay mulches in spring when it’s cool and damp, as this can attract slugs. Remove any perennial weeds before laying a mulch. In dry weather give the ground a really thorough watering before mulching.
  • Most mulches need to be spread a minimum of one to two inches deep. Some, like straw, can be laid much thicker than this, while grass clippings should be applied in thin layers at regular intervals to prevent them becoming smelly and slimy.
  • It’s a great idea to mulch bare soil to protect it from harsh weather and to keep weeds in check. Lay sheets of thick cardboard so that the sheets overlap by at least a foot, and weigh them down using bricks or stones. This is a good way to protect soil over winter. In fall or early winter, spread out a layer of organic matter such as compost or well-rotted manure to improve the soil before laying the cardboard on top.
  • Paper mulches suppress weeds and also help to retain moisture. Cut a cross shape in the paper, dig a hole and simply plant through the paper. Water through the slot.

See the Almanac’s complete Mulching Guide for more information.

Laurel (not verified)

11 months 1 week ago

What about the mulch promoting squash bugs?

That’s a good point. If you use mulch, don’t lay it right up to the base of any plant.

And if you get back squash bugs, we should suggest you leave the area bare. Count on the row covers to hold in moisture while plants are small. Then once plants are large enough to shade the ground, remove cover. Cut the larger lower leaves when they start to die, and put them in a hot compost pile. 

Melanie Eaton (not verified)

4 years 10 months ago

Used wheat seemed to be clean, weed free straw. Guess what I got? Grasses galore.
More backtracking work.

Yes, it sounds like the straw obviously had lots of wheat seeds within it, which have sprouted. The best course of action now is to gradually weed them out, probably by hoeing. Once some control is re-gained, look to mulch with materials from a trusted source where you know there won’t be any stray weed seeds. Leaf mold and garden compost are consistently the best options for mulching and will be incorporated into the soil quite quickly to improve it’s structure. Top up mulches often.

Donna Banting (not verified)

4 years 10 months ago

Would it be a good idea to put straw on my pots of tomato plants? The pots are the large black ones that trees come in and are great for growing peppers and tomatoes but dry out quickly. My only concern is that, when I water, most of it might run off. I am usually watering on the fly in the morning before work.

Yes, you could mulch the top of pots. Tomatoes produce roots along their stems, so in fact a top-up of compost can often be a good choice of mulch, as additional roots will go out into the mulch and help support and feed the plant. If you use seed-free straw then just be careful to water into the straw so it doesn’t bounce or run off the top. It should work fine.

Melanie Eaton (not verified)

4 years 10 months ago

In reply to by Donna Banting (not verified)

Line your big pots with layers of paper, non shiny stuff. Will help maintain dampness levels and help keeps roots cool.

Dorothy Collins (not verified)

5 years 10 months ago

Loved the video!!! He didn't explain the newspaper, but, obvious, I guess.
A man told me once that newspaper then that black material like a tarp material (in various thicknesses) on top really stops the weeds! It does.
I also liked esp. the tip about the cardboard! Very useful. Thanks!

Hi Dorothy. Really delighted you enjoyed the video! Hopefully some useful tips in there. I really do recommend plain cardboard as an excellent base mulch over winter. It's also great laid one or two sheets thick on paths within a vegetable garden, which are then topped up with shredded bark or similar to give an attractive finish. You can then peel back the bark and top up the cardboard every six to 12 months to keep the paths weed-free at all times.

Please let your readers know - Although paper and cardboard do a great job of blocking weeds, can they also attract termites to your property!
A couple years ago I found out a neighbor's house had active termites. I called a termite company to do an inspection of my property, luckily mine was clear. While doing the outside inspection he saw that I was in the process of putting in raised vegetable gardens, complete with cardboard to kill the grass and weeds. I was told to get rid of the cardboard right away as it is like candy to termites!! A by-product of wood, it is soft, tasty, and easy to eat...just like candy is for us. Of course I decided to leave it thinking it would quickly decompose and there wouldn't be any problem. Well...this past March when I got outside to start getting the boxes ready to plant I noticed the wood was in bad shape. Investigating, I found all three boxes were disintegrating and infested with hundreds of termites !!! I was horrified. The boxes along with a pile of small tree twigs/branches (also full of termites) have been removed from my property. Sounds all fixed right? Well, if you do some research you'll find some scary info on how far they actually travel from their nests to find food, and how deep in the earth their nests can be. Now I will always wonder if and when they will show up in my house.
I know not all parts of the country have termites, but please do some research before using untreated wood or paper/cardboard outside.