Should you use mulch and what are the pros and cons of different types of mulch?


I am the chair of the grounds committee at a condo. We are discussing mulch, including using pine in place of other sources. I would appreciate it if you would direct me to information on:
1. Why use mulch?
2. Pro/con of different mulch
3. Is mulch good for windy conditions?


Jonathan Foster, Home Horticulture Outreach Professional

I’ll answer your questions in original order.

1. Re: why use mulch? Mulch is a multi-benefit addition to your garden beds and is something I consider to be essential for good gardening. Once a bed is weeded, a nice layer of mulch both suppresses further weed growth and makes it easier to spot and pull the ones that manage to push through. Furthermore, the mulch keeps moist soil from dehydrating as quickly through evaporation in the sun and combats erosion by giving falling raindrops a relatively soft layer to land on, as opposed to hard bare soil, which can run off in heavy rain. And lastly, organic mulches break down over time, naturally improving the the underlying soil’s nutritional capability and texture.

2. Re: pros and cons. Please check out our UMaine Cooperative Extension worksheet page on Mulch, Soil, and Compost for a good pro/con list. I will also note that I don’t typically recommend landscape fabric or plastic as they tend to tatter over time and leave you with strips and tendrils all through the bed. That said, many people use such materials and are happy with the results.

3. Once the mulch is in place and has withstood two or three good rainfalls, it’s a pretty sturdy layer in the garden. Storm winds might give you trouble, but no more than anything else outside during extreme conditions. Likewise, applying straw mulch on a windy day might produce a comical scene. Otherwise, you should be fine.

For general advice, in no particular order, I would say avoid colored bark mulches as the dye is an additional chemical going into the garden. Also avoid any fresh green materials, as their break down can sometime tie up soil nutrients as microorganisms busily feed away on the decomposing material at the top. Rock mulches can be attractive, but have a tendency to work themselves out into lawns and can be a hazard for mowers. Mulch can be a hiding spot for pests and pathogens, so you don’t want to run the mulch right up to the plant stem–leave a little circle of space down at the base. As you drive around town, you may note something we call “volcano mulching” on trees, where the mulch is piled up against the bark in a cone shape. This can lead to rot in the tree–mulch should be a 2-3″ deep, flat disc on the ground around the plant. And a good rule of thumb to remember is that the larger the individual units of a mulch, the longer they will take to break down.

Good luck and happy gardening.