The Ultimate Guide To Garden Mulching

Mulching your garden is an excellent way to improve soil health, reduce weeds, retain moisture, fewer pests, stronger plants, enhance plant growth and a more attractive garden, then mulch could very well be the answer.

What is mulch?

Mulch is a soil covering that is intended to improve the condition of the soil underneath. It is spread on soil or compost. There are numerous forms of mulch, each with unique features, benefits, and potential problems. Your gardening goals will determine which type you choose.

What are the benefits?

Mulch helps to enhance the soil around your plants. Most varieties preserve moisture in the soil and assist to minimize weed development. It also protects your plants’ roots over the winter by minimizing the number and intensity of freeze-thaw cycles. Some varieties release nutrients into the soil, which can help replenish lost nutrients and improve soil fertility. Other types are effective in discouraging pests. In general, mulched gardens thrive. Mulching your garden also saves time spent on watering and weeding, which are two of the most time-consuming aspects of garden or allotment care. Depending on the type you select, it might also make your garden appear neater.

Choose the right type of Mulch

Organic Mulch (Biodegradable – breaks down over time, enriching soil):

• Wood chips / Bark mulch: Great for flower beds, shrubs, and trees.
• Straw or hay: Ideal for vegetable gardens (make sure it’s weed-free).
• Grass clippings: Adds nitrogen but use in thin layers to prevent matting.
• Compost or leaf mold: Adds nutrients and improves soil texture.
• Pine needles: Acidic, good for blueberries or azaleas.

These will eventually degrade and return nutrients to the soil. This implies they’re excellent at replenishing soil nourishment and increasing fertility. Biodegradables are effective in locking moisture into the soil and reducing weed levels. They are less successful in deterring pests, however.

Inorganic Mulch (Non-biodegradable – long-lasting, doesn’t break down):

• Gravel or pebbles: Ideal for succulents or xeriscaping.
• Plastic sheeting / Landscape fabric: Good for long-term weed control, but it reduces water penetration.
• Rubber mulch: Durable for playgrounds or paths, but not ideal for edible plants.

These mulches have no effect on soil nutrition or health since they do not decompose. They can still help with weeds and moisture levels. One of the key benefits is that they can be used decoratively with great impact. Choosing a mulch primarily on how it looks rather than how it will improve your soil introduces a new level of landscape design concerns. Sheeting may not appear to be mulch in the classic sense, but it actually is. Draping a sheet over a fresh or overgrown flower bed is an excellent approach to eliminate weeds: you may cut holes in the sheet for planting and cover it with other mulch materials if it looks unpleasant.

List of Common Mulch Materials

• Grass clippings.
• Garden compost.
• Chopped leaves.
• Mushroom compost that’s been spent.
• Hops that have been spent.
• Wood chip.
• Processed bark.
• Manure.
• Straw.
• Seaweed.
• Slate.
• Pebbles.
• Chipped stone.
• Aggregates.
• Gravel.
• Seashells.
• River rock.
• Glass.
• Sheets of fabric.

How to mulch your garden

Applying mulch is quite a simple job. You just need to spread it out onto the soil in a layer between two and three inches thick. Here are some best practices for mulching, as well as some things you must be careful to avoid:

• Covering small plants entirely, as this can smother or suffocate them.
• Piling too much mulch against plants, as they can struggle to grow.
• Too close to trees: you should not mulch right up to the tree.
• Before mulching, pull out any weeds right down to the root. This will stop them from growing underneath.
• If you’re using a biodegradable mulch, you’ll need to replace or relayer every year as it begins to break down. Doing this will ensure that your garden continues to feel the benefits.
• Whack the old stuff in the compost if you have one.
• Put mulch out in small piles initially, over the whole area you’re planning to cover. This makes it easier to gauge how much you’ll need. Rake the piles once they’re out to create even coverage. Once this is done, water the top layer gently. Enough to dampen it but not so much that you create any puddles, which can damage the mulch and reduce its effectiveness.
• Mulching will deliver the most benefits if done between mid-spring and autumn. This is when soil is warm and moist, giving plenty of temperature and moisture for the mulch to lock-in.

Apply the Right Amount of Mulch

• 2-4 inches: Ideal for most mulches (bark, straw, compost).
• 1-2 inches: If using finer materials like grass clippings or sawdust.
• Avoid piling mulch too high (also called “volcano mulching”) around tree trunks—it can trap moisture and invite pests and rot.

When to Mulch

• Spring: Add mulch after soil warms up to lock in moisture and prevent weeds.
• Fall: Apply to protect plants from winter freezes and improve soil over time as the mulch breaks do

How to Mulch Grass

Adding mulch to grass is an excellent way to repurpose bio-waste, whether it be grass cuttings or fallen leaves. This is good for your garden and helps to reduce the amount of waste going into landfills. In spring and summer, grass or leaf mulch will decompose and improve the health of your lawn. 

How to Mulch Newly Planted Trees

For trees, a medium texture works best. Fine mulch might compact too tightly, depriving the tree of oxygen, but coarse mulch cannot contain enough water. Mulching too close to a tree, or putting it too thickly, might be detrimental. Both of these items can deplete the roots of oxygen and impede the tree’s growth over time. 

How to Mulch Perennials

Organic is ideal for perennials since it refreshes the soil with the nutrients they require year after year. Other plants can be rotated and the soil refreshed by turning the compost, but mulch is the best source of nutrition for perennials. A layer two to three inches thick works well. 

How to Mulch Vegetables

Mulching vegetables can be done in the winter after they have been planted out. You will need four to six inches. Sawdust, straw, and wood chips are popular vegetable garden mulches. These provide good overall protection for vegetables. Some veggies are better suited to other sorts; for example, tomatoes and other heat-loving plants may prefer something thicker, so it’s important to understand your crops’ requirements. 

Are there any disadvantages?

There are a few potential drawbacks to mulching in general, and some mulch varieties have unique downsides. Mulching too close to tree stems can leave them susceptible to disease. Following the steps above should prevent this from happening. Some combinations, rather than protecting your garden from weeds, can instead attract them. To avoid this, make sure to purchase high-quality products. As previously stated, organic pest control is ineffective, and non-biodegradable mulches do not improve soil quality. 

It is worth assessing the suitability of the type you intend to utilize to ensure that it is appropriate for your requirements. Mulches containing wood, for example, can remove nitrogen from your soil; if you use these, you must compensate.

Here are a few questions we’re often asked.

Can you put mulch over weeds?
No! You should remove weeds first, including the roots.

Can you put fertilizer over mulch?
Yes. Applying a thin layer on top and watering gently will ensure the fertiliser reaches the soil beneath.

Do you have to remove old mulch before putting a new layer down?
Yes. You should only add a new layer once the previous layer has rotted away completely, otherwise, you risk layers becoming too thick.
Theoretically you can put a new layer of organic over an old layer of the same type, but we still recommend removing the bottom layer.

Should you water before or after?
Ideally just afterwards, but the soil beneath the mulch needs to be damp. You may need to water if it’s dry.

Conclusion:

Mulch is an incredibly useful and versatile tool in the gardener’s arsenal. It has the potential to deliver all sorts of benefits, depending on your needs and the type you use. This guide introduced the different types and their top-level benefits. You should now have everything you need to decide which is best suited to your garden. Whether you go for biodegradable or non-biodegradable, mulch is a great way to quickly improve the health and aesthetic appeal of your garden.