Honeybeem,

You can use any mulch you want. I use whatever is available, including but not limited to: straw (better than hay because it doesn't have seeds), hay (even old, half-rotted hay is fine as it enriches the soil as it breaks down), grass clippings, shredded paper, pine bark fines or shredded hardwood mulch, sheets of cardboard or sheets of paper (as a barrier layer under other mulch), chopped/shredded autumn leaves, etc.

To keep weeds from growing up from underneath the soil and coming up through the mulch, I like to lay down a barrier like 12-14 sheets of newspaper or heavy cardboard and then put an organic (in this case, organic meaning once-living) mulch like straw or grass clippings or bark mulch or whatever on top of the paper or cardboard. The newspaper or cardboard also prevents weed seeds that sprout in the mulch from growing down into the soil, as long as you pull them before they manage to work their roots down into the cardboard or newspaper.

I usually start out in the spring with a layer of pine bark mulch or shredded leaves because that is what is left on the surface of the beds from last year. (Keeping your beds mulched heavily after the growing season ends will keep winter weeds from sprouting in your garden and leaving you a big mess to clean up before you begin planting in late winter or early spring.)

I rake the mulch back if I am sowing seeds and then gently rake it back (using my hands or a small trowel) around the young plants after they are up and growing. If I am transplanting, I rake away the mulch in the area I'm going to put a plant, dig the hole, plant it, water it in and then pull the mulch back over the soil. One thing I am careful about is to make sure the mulch comes up pretty close to the young plants but doesn't touch them during the rainy season.

One thing about mulch is that it is generally cool and moist and attracts certain critters like snails, slugs, pill bugs and sow bugs, etc. In my raised beds, slugs and snail are not a problem--we just don't have them here in our heavy clay soil in southern OK, but I use organic snail and slug baits to keep the pill bugs and sow bugs (we called them doodle bugs when I was a kid) away from my plants. There are many brands, and the key to finding an organic one is to find one that's active ingredient is iron phosphate, which is harmless to pets and wildlife. You don't want to use the chemical one that has metaldehyde as an active ingredient because it is toxic. I generally use whatever I can find, usually Slug-Go or Slug-Go Plus (especially formulated for slugs/snails plus doodle bugs) or Escar-Go! if I am shopping in an organic nursery, or if shopping in big box stores, one commonly seen organic brand is from Safer. I mention the snail, slug and doodle bug issue because they like to live in mulch, and they are great decomposers of organic material, but they also like to feed on young green plants especially if you have a large population of them. I put the snail and slug bait down on top of the mulch, following the directions on the package, just as soon as I put the mulch on the beds (unless rain is expected that day). Rain can wash it away, so I try not to put it down if rain is in the forecast, although this year I've put it down twice already because rain is in the forecast every day.

I start out with a fairly thin layer of mulch--an inch or two early in the season (March) when the ground is still cool because mulch keeps the soil from warming up as quickly. Then, as the growing season goes on and the temperatures warm up, I add more and more mulch. I use a grass catcher to catch grass clippings in the yard sometimes and put those on top of the existing mulch in a fairly thin layer (too thick and they get yucky). Other times, I use the mulching feature of the mower and let the clippings fall to the ground where they will feed the grass as they decompose.

Mulching strawberries can be a little iffy. The sowbugs and pillbugs I mentioned, and many other garden pests as well, love strawberries. I'd probably use fresh, dried straw around the berries because the straw would not be as attractive to sow bugs and pill bugs as bark mulch or something similar would be.

If it is raining very, very, very heavily where you live, you might not want to mulch too heavily because the mulch will help keep the soil moist even if what you want is for the soil to dry out some. Even a fairly thin layer will help suppress weeds somewhat until the soil dries a little and you can add more mulch. By the time the real heat arrives in late June, I like to have 4" of mulch on the beds and I arrive at that amount by continually adding a little mulch every week as I get the chance.

Finally, although contaminated mulch is not a huge issue, you do have to be careful. There have been some instances in the last decade where both hay/straw mulch and compost have contained residue of a specific chemical harbicide that failed to break down as expected. It happened in this country in the early 2000s and it happened in Great Britain last year. In Great Britain, I believe it was both compost and manure that was contaminated. And, if my memory is correct, early in the 2000s it was compost, manure and mulch because a lot of people use hay and straw as mulch. I'll link a previous thread that discussed it. When I get hay or straw, I am careful to make sure it has not been sprayed with the types of herbicide that have been a problem in mulch and compost in recent years. I believe this herbicide is no longer found in commercially produced mulch and compost in this country, but you can still get it in hay or straw you purchase (or receive as a gift from local farmers and ranchers) because the herbicide is commonly used to kill broadleaf weeds in pastures and fields.

Some of my neighbors who ranch use this herbicide in their fields, so I can't use their straw or hay in my garden as mulch. You can to be careful because if it contaminates your soil, your garden will die and you won't be able to grow anything in that soil for 2 to 5 years depending on how heavily contaminated your soil is.

The odds are very slim you'd get hay or straw with these herbicide residues, but is has happened to some people and it does continue to happen every now and then, so I thought I should mention it.

And, if your municipality offers free or low cost mulch or compost made from grass clippings and shrub/tree trimmings collected by the city, be sure you wear gloves when spreading that mulch or working in it. Why? Because those mulches often have ground-up poison ivy as one of their components.

Dawn

Here is a link that might be useful: Compost and Mulch Contamination

Dawn,
Now I understand so much better about mulching, you answered my question and then some!! I really appreciate your quick reply and thoroughness. Now to go about carrying it all out! I had just one more question, how close should the mulch be to the plants? Should there be some room for water to get directly to the plant or will it get enough water dripping through all the mulch and newspaper/cardboard? Thanks again for helping!

Honeybeem,

The moisture will soak into the mulch and any underlying newspaper or cardboard and work its way down into the soil, so that's not a problem. I just leave a small area--maybe a half-inch or so between the edge of the mulch and the plant stalk--what you want is to not have the mulch touching the stalk during excessively rainy spring weather because sometimes if a stalk stays too wet, it is more prone to rotting, or bacterial or fungal infection. As the season goes on and the plant's main stalk or stem grows, it will make contact with the mulch, but that's OK--it usually is much drier by then.

Once hot, dry summer arrives, if you find yourself needing to water the garden, it is preferable to use a soaker hose so water can drip down slowly through the mulch and into the soil and that also reduces foliar disease by keeping the foliage dry. In a wet year like this, though, there's going to be some foliar issues just because of the high humidity and excess moisture.

I forgot to add the another benefit of mulch is that it reduces the incidence of soil splash and that, in turn, can reduce bacterial/fungal diseases that reside in the soil and are carried up onto plants by splashing raindrops.

And, too, if you have access to sawdust, some people use it as a mulch--I never have because I don't have any sawmills around me.

Dawn

Ok, thanks for the information!

If you do use sawdust it is best to only use it after it has had a year or two to rot some, or to add some nitrogen to it. If used too fresh it can tie up soil nitrogen. It is also pretty acid so for more alkaline loving plants--carots, lettuce, cabbage, broc--you may want to add a scattering of agricultural lime or a light dusting of woodashes, being careful to keep the ashes back from the stems of the plants We used sawdust for years mining a very well rotted mountain of it at a nearby abandoned sawmill. Then the owner sold the mill and the new owners burned and dozed the whole site (sob)