What is Silver Mulch?
Silver mulch is a thin, reflective silver-colored plastic film, made of a material that is reminiscent of a thin garbage bag. It is usually three to four feet wide, and is sold on a spool in rolls between 50 and 600 feet long.
Where To Buy Silver Mulch
Silver mulch can be purchased at some farm supply stores, and can be mail-ordered from many sources. Make sure that the silver mulch you purchase is UV resistant, and is an appropriate width for your garden rows.
Depending on what size roll is purchased, silver mulch can cost as little as 5 to 7 cents a linear foot, or as much as 20 to 25 cents a linear foot, not counting taxes and delivery costs.
Why Use Silver Mulch?
Silver mulch combines its unique reflective properties with standard black plastic mulch's strengths (providing a weed barrier, moderating soil temperature, etc.). This combination produces a plastic mulch that scatters light in way that has been proven to reduce the ability of certain insect pests, including aphids and flea beetles, to infest crops.
Silver mulch also reflects sunlight back into the plant canopy, and the additional light helps some varieties of vegetable plants grow bigger and more quickly than they would with light-absorbing black plastic mulch. In research trials conducted in Pennsyvania, peppers, tomatoes and eggplants were some of the types of vegetable plants that benefitted from being grow in silver mulch, especially in cases where insect pests were of special concern.
In research trials, silver mulch has been shown to increase pepper yields by up to 20%. It was also shown to significantly reduce the incidence of aphid infestation in vegetable crops, as well deter Colorado potato beetles from attacking potato crops.
Is Silver Mulch Right for Your Garden?
Silver mulch is a good choice for gardeners who are having serious problems with insect pests such as flea beeltes, aphids and Colorado potato beetles in their tomato, pepper, eggplant or potato crops. However, gardeners who live in Northern areas need to be aware that silver mulch doesn't help the soil heat up as well as black plastic mulch does, so using silver mulch in cooler climates may actually slow plant growth because the soil underneath the silver mulch will be cooler than bare soil or soil beneath non-reflective plastic mulches.
How to Use Siver Mulch
Step 1. Prepare your garden soil by making sure that it has adequate fertility levels and an appropriate soil pH for growing vegetables. You can find out what your soil's nutrient levels and pH are by having a soil test performed through a private lab or with help from your county's cooperative extension office.
Step 2. Till your soil to create garden beds. Either raised beds or beds level with the surrounding soil surface will work.
Step 3. Lay your drip irrigation line along your garden bed (if you use drip irrigation in your garden). If you're going to use silver mulch, you will need to provide your crops with some form of irrigation because rainwater won't be able to penetrate the mulch to reach your crop's roots. Drip irrigation is usually the method of choice, but hand watering with a hose or watering can is OK too, as long as you do it on a regular basis.
Step 4. Place the silver mulch on top of the garden bed silver side up. Make sure that the mulch is fairly taut, not saggy. Once the mulch is laid out, weigh it down by buring the mulch edges in a layer of soil.
Step 5. Put your plants into the plastic mulch. In order to accomplish this step, use a sharp knife or a pair of scissors to cut a small slit (either "X"-shaped or a straight line) in the plastic mulch. The slit should be as small as possible, just big enough to allow you to put a vegetable transplant into it. Once you have made the cut in the mulch, plant your plant as you usually would, burying its entire root ball in the soil beneath the mulch.
If you're using drip irrigation, make sure that you don't cut your drip irrigation line when you cut the mulch, and make sure that you place your plant near the drip line.
Step 6. Removing silver mulch at the end of the growing season. Since silver mulch is not designed to last more than one growing season, the mulch should be removed and disposed of as part of your winter garden clean-up. The silver mulch is not biodegradeable, and will need to be thrown away.
Although some would argue that this makes silver mulch an environmentally-unfriendly product, it's important to consider how much pollution and waste you prevented by growing your own garden produce, even if you used silver mulch in the process.
Shimmering Silver Success
As the growing season progresses, silver mulch is likely to help your crops remain weed and insect free and, in some situations, will increase crop yield dramatically. Though results vary from garden to garden, many gardeners, including myself (I wouldn't even attempt to grow eggplants in my garden without using silver mulch!) have found silver mulch to be very helpful. Hopefully, silver mulch will be a shimmering success in your garden as well!