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MANY GARDENERS NAME 'MULCH' AS BEST GARDENING TOOL
I attended a Master Gardener meeting recently where we were asked to introduce ourselves by describing our most useful gardening tool. Of the two dozen gardeners, about 10 said "mulch" was their most useful gardening tool, and another four said "my Mantis tiller."
I don't own a tiller but, based on the responses, if I ever buy a tiller, it will be a Mantis. No other brand of tiller was mentioned.
The mulch the gardeners were referring to is shredded wood that is laid down around shrubs and perennials to keep the ground moist and cool, control weeds, and enhance the garden's appearance.
I recently priced hardwood mulch because I'm considering using it instead of the wood chips I've used for six years. Hardwood mulch is available from one local supplier for $15 per yard. A full truckload is about 20 yards and will cost approximately $300, plus a delivery charge of $35.
The shortcomings of wood chips, in my experience, are that they blow around on dry, windy days and end up on my lawn, and robins and other birds are constantly tossing them every which direction in search of worms and other insects.
The ideal way to use mulch is to prepare the seedbed first, then lay down the mulch. Preparing the seedbed may involve killing all vegetation with Roundup or some other chemical, tilling the soil so it's friable, amending the soil with compost or other organic materials, and removing rocks and thick roots.
Planting takes place only when an ideal seedbed has been prepared and covered with a 2-4 inch layer of mulch. To plant shrubs or perennials in this ideal seedbed, simply push away the mulch, dig a hole, drop in the plant, and re-cover the ground up to the base of the plant with mulch.
Some gardeners lay down a porous fabric below the mulch to prevent weeds from taking root. Plastic is not a good choice because it prevents water from penetrating the soil.
For many of us, this ideal approach to creating a mulched garden isn't always feasible. I have flowerbeds that aren't mulched and the soil contains too much clay, along with established stands of quack grass and other undesirable weeds. The smart thing for me to do, of course, would be to remove the plants, fix the soil, then replant the perennials and shrubs and lay down mulch. This is also a lot of work.
The mulch supplier I contacted offers five choices: hardwood wood chips for $16/yard, coarse-grade hardwood shredded mulch for $15/yard, fine-grade hardwood shredded mulch for $17/yard, cypress mulch for $45/yard, and red cedar mulch for $40/yard.
One thing I know for sure about mulch is that the nicest looking landscapes use mulch as described above and add a new layer of mulch each year.
Treated-timber raised beds
There is a misconception that treated timbers can't be used for raised beds because the timbers give off dangerous toxins that are harmful to plants or render fruit or vegetables unsafe to eat.
While that may be possible, there is no actual research that proves that treated lumber is dangerous for use in gardens, according to Jill MacKenzie, Wright County Extension Educator and horticulturist.
By treated lumber, MacKenzie is referring to CCA-treated wood (also called "green-treated" wood), and not creosote-treated railroad ties, which are not recommended for gardens.
"There is plenty of research data that show some forms of arsenic to be poisonous, and data that show plants take up arsenic from soils with high levels of the element, and data that show that CCA-treated lumber releases arsenic into the soil.
"However, to date, no studies have shown that CCA-treated lumber in a raised bed releases arsenic or other dangerous toxins into garden soil in a form and/or amount that plants will accumulate, and that the accumulations are in a form and/or amount that are toxic to people handling flowers or eating vegetables grown in those gardens."
MacKenzie and a team of University of Minnesota researchers are conducting a research project that will study the levels of arsenic in garden soil, measure how levels of arsenic change as treated wood breaks down, and attempt to find excess arsenic in the tissue of plants grown in this soil.
One of the shortcomings of CCA-treated lumber research, according to MacKenzie, is that nearly all the studies have used new wood. The U of M study will focus on old lumber and garden soil that has been exposed to the lumber for 10 or more years.
MacKenzie and her team are looking for research sites (home gardens) where CCA-treated lumber has been in contact with the soil for many years. If you have a raised bed that qualifies for this study and would like to participate, contact MacKenzie via email jmackenzie@extension.cumn.edu.
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PUTTING DOWN ROOTS:
A Delightful Blend of
Gardening Wisdom, Wit
and Whimsy
$10 + $2 for shipping
by Cliff Johnson |
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