How to Use Straw Mulch in Your Garden

The application of straw mulch will help protect your vegetable garden from disease, reduce watering, and more. Horticultural expert Sarah Jay discusses this resource and how to use it.

A person wearing gloves holding straw mulch in hands, appearing yellow and dry placed at the base of a plant

Contents

Choosing the right mulch is a big deal for gardeners. Depending on what you want to grow, wood chip mulch is a good option, or maybe grass clippings are best. But for most working in a raised bed vegetable garden, straw mulch is one of the best mulches out there. 

Straw has many benefits. It promotes water retention and prevents soil compaction. It keeps plant roots healthy and is beloved in the organic gardening world. So if root health and irrigation are an issue for you, maybe straw is the answer.

In your home garden, you have to know which organic matter is best for mulch, and which type is most appropriate for your situation. So before you spread more mulch on your garden bed, let’s cover some tips for using straw as a mulching medium. 

Garden Straw

GardenStraw premium mulch:

  • Builds your soil with organic material over time
  • Lends a natural and clean look to garden beds
  • Retains moisture
  • Minimizes weeds

buy at Epic Gardening Shop

What Is Straw Mulch?

Interestingly, there is more than one type in the “straw” category. Each of these has its place in varying garden beds. To figure out which of these straws is the best garden mulch for you, let’s examine each variety. 

Straw Mulch

Close-up of a garden rake resting on a layer of dry straw covering a garden bed with growing tomato seedlings.
They are dried plant parts, often coming from cereal or grain stalks.

These are the remnants of cereal and grain crops. Straw differs from hay only slightly because it’s the remaining hollow stalks of wheat, barley, or rye. 

Straw typically does not contain seeds. This prevents the need for pulling weeds constantly in the growing season. It’s a great way to help you do a lot less work in the ground and gives your yard splashes of beautiful golden color. 

You can usually find large bags of straw at nearby hardware and tractor supply stores. You may also find straw in bales at variable costs. 

Certified Weed Free Straw Mulch

A wooden raised bed filled with garlic plants growing amidst a layer of protective straw mulch.
The typical options in stores may contain weed seeds.

It is likely that you’ll obtain straw that isn’t weed-free if buying it in a standard bale or bag. If you’re concerned about weed seeds in your mulch, search for a certified weed-free straw instead.

Just like regular straw, these are cereal and grass crops that have been harvested, but these are steam-treated to remove weed seeds that make gardening laborious. This type of mulch is great for your garden or for composting. 

We’re particularly fond of straw that undergoes an all-natural process that filters out wheat and weed seeds, such as GardenStraw. The finer sizes it’s been chopped and split into make the application incredibly easy, and it’s virtually dust-free.

Some livestock supply companies also produce weed-free straw, but it may include wheat or barley seeds. This means you may end up with unexpected wheat or barley plants in your garden.

Hay Mulch

Young garlic in a bed mulched with hay
Seeds of weeds and other invasive plants are often present in this variety.

Unless you’re doing active composting, hay mulch might be the least desirable straw out there because it contains the most seeds from weeds and invasive plants compared to the other aforementioned mulch types. Pure hay is often used to feed livestock and is sourced from farmers and ranchers who have a surplus on hand. 

Although it breaks down easily, mulching with hay can unintentionally steal nutrients from your garden because of the quantities of weed seeds that may be contained therein. As weeds grow, they pull nutrients away from other plants. 

If you don’t mind pulling weeds often, hay might be an acceptable option for your garden. If weeding time doesn’t appeal to you, try one of the other mulch materials mentioned here. 

Alfalfa Mulch

Alfalfa remnants, appearing deep green and scattered, piled on top of each other covering an area looking dense and slowly drying up
They start out green and become a golden color as they dry up.

This is a specific cereal crop that is steam treated to remove seed heads. Unlike basic straw and hay, alfalfa mulch starts out green. As these mulches break down they turn golden and provide a wealth of nutrients into the soil, especially nitrogen, which is an essential part of healthy garden soil. After all, alfalfa meal is used as a nitrogen supplement in organic fertilizers!

There are a couple of downsides to alfalfa. First, it’s expensive. Although organic materials like this are great for early root development, some of the nitrogen needed in the vegetable garden could evaporate into the air if it is not applied properly. But overall, it’s a great garden mulch you can find in most garden centers. 

Pine Straw

A pile of dried up pine needles, appearing to have a light brown color, placed on top of one another forming a dense layer of plant material
Needles from pine trees can also be a good option that doesn’t break down quickly.

This is fallen, dried pine needles that act just as other mulches do in garden beds. If you’re into regenerative agriculture, and you live near pine trees, this organic material is great for garden mulch. For those who live near pine trees, it’s practically free. Otherwise, it’s about the same price as straw. 

It’s a great garden mulch because it doesn’t compact as it breaks down, so it won’t create a mulch layer that causes a water table to form, choking out your plants. Pine straw doesn’t contain seeds either so you won’t have to worry about weeds in your mulch or in your garden. 

Some have expressed concern about whether pine straw is acidic. If it has turned brown and naturally fallen from the tree, it’s essentially pH neutral. Green pine needles are still mildly acidic, but the dry brown ones have lost most of that acidity.

Pros And Cons Of Straw Mulch

Here we’ll get into some of the intricacies of straw mulching and how it can help or hurt the plants in your garden. Often disadvantages occur with improper selection and application of mulch. Gardeners would do well to consider which layer of mulch will be best for their soil. 

Benefits

Two smooth yellow fruits rest on a bed of dry straw, partially shaded by green stems and broad leaves in a lush garden.
It can yield various benefits, including better moisture retention.

Each type of mulch mentioned above will help your soil retain moisture. That means you won’t need to water as much and you can save some time and money. Established plants in healthy soil, watered by drip line, and covered in mulch are in an ideal environment. 

This is especially the case with certified weed-free mulches. Here, there are fewer weeds to worry about. Without invasive weeds, these mulches help reduce soil erosion. Topsoil loss is something a lot of regenerative gardeners are hoping to combat. Mulch is a huge part of that fight to preserve topsoil. 

Mulches also keep disease down in your garden. As they break down, they not only add nutrient content to the soil but also prevent the proliferation of bacteria and fungi that may be lying fallow in the soil. Concurrently, mulches keep the planting soil within the bed and prevent runoff. They make gardens look great too, adding a splash of color here and there.  

Depending on the source of your mulches, they can cost anywhere from nothing to under $100 for the first application. Often straw mulches can come from sources where they’re no longer desired. Find a farmer who wants to offload some straw and you’re set. 

Finally, in hot climates, the light color of a straw mulch can help reflect extra heat away from the soil. This maintains the right temperature for seed germination without allowing the soil to bake in the sun. Similarly, it protects soil in cooler climates by acting as a blanket over the soil’s surface, keeping it warmer than it would be if exposed.

Drawbacks

A close-up of small strawberry plants with white flowers, surrounded by straw mulch on the ground.
This option often decomposes fast compared to wood chips.

Because straw decomposes into the soil quickly, especially compared to wood chips, it may not retain its appealing golden appearance for as long as some would like. Although they’re still regulating soil temperature, you’ll need to spread a mulch of this kind at least once per growing season. 

A hay bale (or bales) can be heavy and hard to take apart, and they might have weeds within them. Some of them may even promote soil-borne diseases if they are applied too thickly or thinly. But even a great job of laying mulch can be completely offset by constant weeding around your plants. 

If you’re interested in more expensive alfalfa or hay mulches, consider a good cost-benefit analysis before spending money. Sometimes larger gardens would do just as well with a free source of mulch rather than something that will cost a lot of money to incorporate in composting or garden soil. 

Probably the least common problem with straw mulches is they could contain insecticides and herbicides that kill off good nutrients present in your soil as they break down. Consider the source before purchasing. Generally, this is not a major issue, but it’s still possible.

What you’re looking for is something that doesn’t contain harmful chemicals, weeds, or pests. If you’re unsure, do some research into your straw source first. 

Where To Use Straw Mulch

There are appropriate times to mulch your garden, and inappropriate times too. Here are a few tips on different ways to apply.

Seed Starting 

Close-up of water spraying young kale seedlings growing in soil covered with straw mulch.
A thick layer may suffocate seedlings.

You won’t want to mulch the soil right when you direct seed because it could choke out seedlings or provide too much moisture, preventing sprouts altogether. 

Instead, wait until your seeds sprout and mature to the point where they are high enough above the soil so that a thin layer of mulch won’t keep in too much moisture. In that same vein, it’s appropriate to mulch around mature, already-established plants. 

Do not apply straw in a thick layer around newer plants. While your compost heap appreciates a foot deep layer, your garden prefers about three to six inches of spread mulch in the planting area. 

Instead of mounding straw up against each plant, make sure there is a small empty area around the base of your plants instead. This prevents choked roots and allows moisture to flow directly to the root system of the plant. It also prevents fungus and bacteria that occur in overly moist garden conditions. 

Composting With Straw

Large round pile of dry straw on green grass in sunny garden.
This material can also be useful as compost.

Straw is great for mulching, and it’s great in composting too. Use it to cover your pile in a layer thick enough to cover green matter, and you’re set for nutrient-rich compost which you can apply to your garden in upcoming seasons. 

You can even use a bale of straw to create the frame for a compost pile. Simply later each bale on the ground in a square or rectangular shape. Then add your compost materials within. As the compost breaks down, so does the straw. There’s no need for wire, tumblers, or piles in this method. 

Use the rich humus compost when you sprout vegetables for the upcoming season. You’ll find gardening with this compost very rewarding, especially if the straw you sourced is free of weed seeds. One way you’ll know the straw is doing its thing is your pile will offset steam in the winter. That’s a good sign things are going as planned. 

Attract Earthworms

A thick layer of wet and damp soil appearing dark brow with countless wigglers moving through the soil with various plant materials
This material can attract earthworms that are beneficial for plants.

One of the best tips I’ve received in my gardening adventures was to incorporate some straw (free of chemicals, of course) into the soil to bring the boys to the yard… the boys being earthworms. I’ve found that adding just a little bit to my beds produces rich soil earthworms love. 

When I’m planting in later seasons, I’ll see earthworms as I dig. Earthworms are always a sign of even healthier soil to come because they leave behind worm castings which provide essential and micronutrients important in vegetable gardening.  

Straw Pathways

A field of flowering lavender bushes features woody stems and fine, silvery-green leaves, highlighted by dense spikes of violet flowers blooming in neat rows over straw-mulched soil.
You can also use it to form pathways, dividing garden beds effectively.

One cool way to use excess straw is to put it in the walkways between your garden beds. Not only does this add some contrast and an element of design to your garden, but it also prevents weeds. Instead of constantly pulling weeds from the garden border, you’ll suppress them with straw. 

Just pull a large handful from your bale, and shake it around walkways. Use a rake to fine-tune the design, and add layers as needed. 

Frequently Asked Questions

Is straw good mulch?

It’s excellent. It doesn’t take as long to break down as wood chips do, and it’s healthier than grass clippings. This mulch acts as a nutrient source and keeps the soil moist and warm in cold months.

Which is better straw or mulch?

Straw is a type of mulch. However, if you’re referring to wood chips, there are different and more appropriate applications for each. Certain plants do well with wood chips while others do better with straw.

Do some research before you make a large decision or purchase to determine which is best for your situation. The straw will break down much faster than wood.

How much does straw mulch cost?

It depends. You could source some free straw bales from a local farm or collect fallen pine straw for free, or you could buy bags from the garden center for about $5 each. Alfalfa can be pretty expensive in higher-quality forms.

Share This Post
A close-up of xeriscaping exhibits lavender and blue fescue flowers. The slender leaves of fescues add texture. Planted along the sidewalk, basking in sunlight, they create a vibrant, water-efficient landscape.

Mulch

6 Mulch Options for Xeriscape Gardens

Planning a xeriscape garden but not sure what kind of mulch to use? Want to know more about the xeriscape philosophy and how to conserve soil moisture with mulch? In this article, certified master gardener Liz Jaros touches on xeriscape principles and offers seven mulch options for a water-conscious garden.

plastic mulch pros and cons

Mulch

18 Pros and Cons of Using Plastic Mulch in the Garden

Plastic mulch can dramatically reduce weeds and improve yields through soil warming and moisture regulation. However, it has a dark side for the environment and soil health. In this article, former organic farmer Logan Hailey explores the science, safety, and practicality of using this product in your garden.

Bed with mulch and green lawn

Mulch

15 Different Types of Garden Mulches & Where to Use Them

Are you looking for the perfect mulch to use in your garden this season? There are many different types of mulch you can use depending on your gardening goals. In this article, gardening expert Liessa Bowen shares some of her favorite types of mulches and where each type can be put to best use.

Knowing how to spread mulch, using hands covered in gloves placing the material near a bush with yellow flowers

Mulch

How To Spread Mulch The Right Way

Laying mulch is necessary for moisture retention, erosion control, and weed reduction. Horticultural expert Sarah Jay explains how to spread mulch in your garden spaces correctly.

Someone wearing gloves pressing down leaf mulch on top of soil of a plant in a pot

Mulch

How to Make and Use Leaf Mulch

Fallen leaves shouldn't go to waste in your garden. Use them as leaf mulch to boost growth and improve soil health. These lovely gifts from deciduous trees build incredible soil! Sarah Jay explains how to make and use your own leaf mulch.

Two pieces of gardening tools laying on top of wood chip mulch placed on the ground in the garden

Mulch

The Pros and Cons of Wood Chip Mulch

Wood chip mulch is often recommended, but what does it actually consist of? Is it good for your garden? Expert Sarah Jay explores the pros and cons of wood chip mulch, and how to use it.