What you need to know about mulch

Mulch, in the simplest terms, is a layer you add on top of your garden soil. There are lots of benefits to adding mulch to your garden but there are also a few downsides you should be aware of so you can choose what will work best for you.

What is mulch

Well basically, mulch is a covering that you put on top of your soil. OK, that’s the key, on top of the soil. And this bit can sometimes cause a wee bit of confusion because sometimes people will talk about compost. Now the thing is compost can be a mulch and we’ll cover that in a bit.

So I had a wee look around my garden at examples of mulch and I use three different types of mulch, in different areas of my gardens. I think that’s actually a good way to talk about it, because it will let me explain why I use different types and what the benefits or disadvantages of each could be.

Two are organic and one is in-organic. Just a wee note though, when I say organic here, I simply mean that it was once a living thing, I’m not using organic in the sense of an official badge saying it’s processed chemical free. These two organic mulches I have are probably the most commonly used in gardening, to be honest.

Shredded bark and straw

In my back garden I use mulch on my flower beds and my vegetables beds.

For my flower beds I use shredded bark I buy from my local garden store which is prepared for use as a mulch, meaning that it has been partially composted and the heat from that process can reduce the chance of fungus and disease that was present in the wood being transferred to your garden. I hear quite often how people use wood hip as a mulch and are then plagued by unwanted mushrooms.

The other organic mulch I have in the garden is straw and I use that in my vegetable beds. Most often, if you catch up with usin our gardening videos, you’ll see me using this in the strawberry bed quite.

So why do I use two different types?

Very simply, I find it easier to move straw around, and as I plant and replant in my veg beds more often than anywhere else, I use straw so that I can move it aside if I want to grass plant som new plants in there. Or even move it completely away from an area if I want to direct sow seeds. Now I could do this with the bark, but I just find the straw is much easier.

However, I don’t like the look of the straw in the flower beds, hence I choose to use bark for them, rather than straw. It’s purely down to how it looks. After all, this is my garden. It’s not an allotment or a homestead or farm etc. How it looks is important to me and part of my enjoyment.

Now this leads me onto the fact that an awful lot of people will use either compost or even grass clippings as a mulch, and both work brilliantly And you can get these form your own garden, compost pile or lawn cuttings and it saves you spending your hard earned pennies at the garden store. Now I don’t use either of these, not because they don’t work but, well for grass its for the same reason as I don’t use straw in my flower beds. It’s purely because I don’t like the look of grass clippings lying around in the garden. Instead I put mine into my compost bin. Compost however, I want to talk about that separately because there is one essential thing that other mulches do that compost doesn’t do as well. We’ll get to that in a sec.

Grit or pebbles

OK so in the garden in front of the house, I don’t grow any veggies. It’s all flowers and shrubs. I only use one type of mulch out there and it’s grit. Ok it’s pretty grit but essentially, it’s grit. This is considered an in-organic mulch, because it isn’t made from material that was once living, like straw or bark.

The main reason we use grit in the front garden is for the asthetic nature of it. We use white grit and it really helps to make all the plants and flowers pop. they really stand out against it and it looks neat and tidy.

OK so lets get into the detail now. Why do we mulch and what are the things to be aware of?

Why do we mulch?

Well quite simply, in summer it helps to keep moisture in your soil. Mulch is a thick layer, about 3 or 4 inches deep that you add on top of your soil. If you mulch your soil, it helps protect it from the sun’s heat, reducing the evaporation of moisture. The flip side to that is that in winter, it’s like a blanket that keeps your soil and your plants all protected a wee bit from the cold and the frost.

The moisture retention is probably the number one reason people mulch their gardens, but there is another fantastic benefit to mulching and that’s weed proofing. Mulch also helps to reduce the number of weeds that come through because it blocks the light to those seedlings. It also helps to prevent new weeds taking hold because that thick layer of straw or bark means there’s no real nutrition for the seeds once they germinate and they whither and die. It makes a huge difference to the amount of weeding we have to do in our beds.

Now, There are two things I’d like to talk about here, in relation to weeds and seeds.

Firstly, compost used as a mulch isn’t quite as efficient at stopping weeds because any seeds that fall into it are then finding a fantastic environment to grow in. So although it can help block the light to those seeds that are under that thick layer, too thick for those seedlings to get going before they need light, it doesn’t then stop the new seeds introduced. Bark, straw and even the grit are much better at the weed suppression.

The next thing I want to mention is that you will often hear people talk about how organic mulch like bark will rob nitrogen form your soil. This absolutely true… but, and it’s an important but. As these organic mulches like bark and straw break down, they do use nitrogen from the soil underneath, but only from the very top layer. So this doesn’t have a detrimental affect on any of your established plants. In fact, it’s one of the things that makes it so efficient at preventing weeds. Robbing that top layer of nitrogen is also robbing those weeds of much needed nitrogen.

I mentioned earlier that I use straw as the. Mulch in my vegetable beds. Well now that we’ve mentioned the fact hat mulch robs weed seedlings of light and nitrogen maybe we should now think back to me saying I use straw because it’s easy to move. If you want to direct sow any seeds into your beds, you should move the mulch away from that area and don’t put it back in place until those seeds have grown into little plants.

Compost, however, is different. Because compost is already broken down, it doesn’t take nitrogen from the soil, in fact, compost adds nutrients to your soil.

One last bonus about mulch

I’ve left this one till last, and it’s something I get asked about a lot.

We use the large pebble / grit mulch in our front garden flower beds as a deterrent to local cats and foxes who were using our flower beds as a toilet. We’ve found that if we have any bare soil they will happily make that “their spot”. However, the avoid the areas with the grit in place. So bonus tip if you have problems like us.