A weed is most simply defined
as: “A plant out of place”. The places those unwanted plants come up in is
where the rub begins. There are rhizomatous roots rummaging around nearly every
garden. Bermuda grass and Johnson grass are two of the most persistent
problems. These we will deal with later. What should be captivating our
attention currently are unwanted plants that come from seed every year.
“An ounce of prevention is worth a pound of cure” is a familiar saying. With respect to weed control, no truer statement can be made. Weed prevention, as opposed to weed eradication, requires advanced planning, forethought, and the ability to see into the future. If your prognosticator is broken, and you fail to take timely action, you will soon receive a reminder in your garden: Noxious Weeds.
Before we go further, I will admit to a certain therapeutic effect that weeding gives. What we are about to discuss will not deprive you of this highly valued anxiety reliever. Weed control is rarely absolute or totally effective, so don’t worry about not having sufficient stress outlets in your garden. There is often a fine line that exists between therapeutic weeding and If-I-don’t-get-these-weeds-back-under-control, I’m going-to-lose-my-mind, weeding. Let’s concentrate on the former so that we may avoid the latter. There is no benefit in revealing our inner borderline-psychotic tendencies, particularly when you are out in the yard, where the neighbors can see you. Gardening is supposed to be a happy endeavor.
There are three routes to take with regard to pre-emergent weed control: Physical barrier, organic and chemical. All have their place and they can coexist, providing you take special care in application and have a thorough understanding of the products you are handling (hint: read the directions on the product label).
A physical weed barrier can be achieved by placing several layers of newspaper or weed barrier mat, such as Typar®. Both methods work similarly. Either will need to be placed directly on the soil and mulch directly above. The best part of using newspaper is that it biodegrades naturally; the worst part of using newspaper is that is biodegrades naturally. That is to say, it does the job well, but you will have to remove mulch and replace the paper barrier at least annually. This method is probably best in the vegetable garden, where you are re-doing it annually anyway. On the other hand, Typar® works great, and lasts a long time (nearly permanent if kept covered from sunlight), and if you have three people available, fairly easy to install (a bit tough to cut and trim by yourself).
Organic weed control can be achieved by using Corn Gluten. Corn gluten meal is a powdery byproduct of the corn milling process. Used for years as a supplement in hog feed, this natural protein is very effective for lawns and gardens as a plant food as well as a weed suppressor. Corn gluten meal products offer a non-toxic, yet effective alternative to traditional, chemical-based weed and feed products for weed control in gardens and lawns.
As a plant food, corn gluten has a N-P-K ratio of 9-1-0, or 10% nitrogen by weight. As a weed suppressant, corn gluten acts as a natural "pre-emergent" - it inhibits seed germination by drying out a seed as soon as it cracks open to sprout. These qualities make corn gluten an ideal 'weed n feed' product. Corn gluten requires re-application every 4 weeks.
Chemical choices are preferred where more broad-spectrum long-lasting coverage is desired. A time-tested, comparatively safe chemical is Treflan. Treflan is a brand name for the chemical trifluralin. Products containing Treflan are often found in other brands of products such as Preen®. As is true in many marketed products, trifluralin found in one product is the same as what is found in another. The only difference is the percent of active ingredient. For this reason, it is always advised to read the directions; read the directions: READ THE DIRECTIONS. All chemicals sold today have been approved safe by the E.P.A. when used in accordance with the directions.
Whether you choose organic or chemical products, they both work best when they make direct contact with the soil; this is where the weed seed germination prevention takes place. That is what pre-emergent herbicides do: prevent germination; they don’t normally have much, if any, effect on seeds that have already sprouted. That is why you should be acting now or at least very soon. It will save you a lot of work down the road. I don’t know about you, but I’m always looking for an easier, softer way.