Newsletter - May 2009

Hi,

It's May Day and raining. What a nice way to greet the month and the seedlings emerging in the garden. I was most worried about the eggplant, but it has sprouted along with the beans, tomatoes, cilantro, basil and sunflowers. That's all the room I have, but the first strawberries are beginning to show color, so I'm happy.

Spring months are notorious for finding some of the worst weed pests, so I'd like to address management practices. Does anybody not have weeds? They can be such a chore, plus they compete with desirable plants for sun, space moisture and soil nutrients. The trick to controlling weeds is to identify the varieties. Go to the library, or look on-line and use the reference sources to learn if you have annual (only lives one season), biennial (foliage the first year and blooms the second then dies), or perennial (comes back every year from the same plant) weeds. The variety determines the type of treatment.

For annual weeds such as sow thistle, annual blue grass, wild oats, foxtail barley, chickweed, cheese mallow, petty spurge, mustard, bristly ox-tongue, and wild radish and for biennial weeds such as plantain, cat's paw, teasel, bull thistle and dock the trick is to prevent flowering. The only way these plants propagate is by seed, so if the flowers are removed along with the unsightly foliage, the weed is controlled. Mowing, or individual clipping are good and organic removal methods. The problem is that annual weeds may sprout, bloom and produce seed within two weeks, or seemingly overnight. So vigilance is required. Also this does not prevent weed seed from blowing in from the neighbor's or from the surrounding fields. If you are not opposed to chemical control, an application of pre-emergent herbicide to the soil according to the label's directions will prevent most seeds from germinating. Need I say that it will prevent any ornamental seed from germinating also? The other recommendation is to use organic mulch with a depth of three to four inches. The seeds may still sprout, but the mulch won't allow them to grab into the soil, so pulling is easy.

Perennial weeds such as dandelion, morning glory, perennial pea, Bermuda oxalis, Bermuda grass, bramble berries, dodder, cat tails and salt grass are much more difficult to control. Perennial weeds typically have more than one way to propagate. Not only will they flower and form seed for aerial distribution, but they also will propagate by some means of stem spits, such as stoles from the grasses, bulbs from the oxalis, or crown off-sets from the dandelion. The root of perennial morning glory and perennial pea will grow to a depth of four feet under ground. Most of us have trouble digging that deeply into our clay soil. If the infestation is small, physically digging to remove the pest is still the best method, but be persistent to discourage re-growth. Usually perennials spread every time they are cut. For large patches of perennial weeds a chemical application, or two or three are required.

I must caution that I see chemicals applied incorrectly often. If a chemical is your choice, do not mow the weeds first. Chemicals rely on being absorbed into the leaves. If you remove the leaves, you've just wasted the chemical. The best time to apply is when the weed is still juvenile (actively growing and before flowering). At this point the weed will drink in the chemical rapidly. Chemicals may still be applied at flowering, but the plant's energy will be directed toward forming seed, so the chemical works much more slowly. I've also seen people try to control weeds when they are brown, or dead, so no longer developing. At this point it's way too late to apply, so again the chemical is completely wasted. If the weedy area is brown, irrigate and return the weeds to juvenile growth, then apply the chemical.

Always read the chemical's label before bringing it home to be certain your target plants are listed and that you have the right equipment for application. You'll find that there are non-specific weed controls that target everything and specific weed controls that target either broadleaf, or grass weeds. Be concerned about toxicity levels. The word "Danger" on a label is the most toxic and dangerous to have. I try not to even buy these products. The second level of toxicity says "Warning" and the third says "Caution". Why bring home a second level if a milder form will do the same thing and be less damaging to the surroundings? Always protect yourself and your ornamental plants from contamination. Never apply in the wind. Be sensible when using and storing this stuff.

I'm going to be offering a three Saturday lecture series on design basics at the "Joe Nelson Community Center" in Suisun City beginning this month. On the 23rd the topic will be dressing up the front garden for curb appeal. The 30th will deal with designing the back garden for individual enjoyment and the third class on June 13th will discuss selecting plants for the garden. The classes will run from 10am to noon. Hope I see some of you there. Have a good month.