Spring is coming sooner than usual. Yesterday, as I walked through the garden, I noticed that my Anemone blanda was blooming. In a normal year (is there such a thing any more?), the anemone doesn’t bloom until the end of the month. I also noticed leaf buds on my roses and clematis. This means that weeds will be sprouting before you can blink your eyes if they haven’t already poked through the soil. Once the weeds sprout, they will compete with your vegetable seedlings for space, moisture and nutrients.
The vegetables that prefer cool weather are lettuce, spinach, carrots, radishes, peas, broad beans broccoli, brussels sprouts and cauliflower. All can endure short periods of frost.
Ironically, the very act of preparing a garden encourages weeds. Weed seeds lie dormant in garden soil by the millions. Turning and tilling the soil, and creating the furrows in which to plant vegetable seeds, exposes these weed seeds to the light they need to germinate and grow.
Ridding a vegetable garden of vigorous weeds can be a backbreaking, time-consuming task. Thus, many gardeners, try, literally, to nip things in the bud in early spring by applying a pre-emergent to stop new weeds from growing. Pre-emergents don’t kill weeds. They’re weed preventers; therefore existing weeds must be removed manually before sprinkling the pre-emergent granules on the ground, creating a chemical barrier that seedlings cannot penetrate.
Gardeners planting vegetable seeds should only apply a pre-emergent once the young vegetable plants have attained a height of close to three inches and exhibit true leaves, the ones above the first set of leaves.
Preen is the best known of the pre-emergents and the barrier usually lasts three to four months. Many gardeners, however, prefer to use an organic pre-emergent like corn gluten. If you choose the corn gluten, be aware that it will only be effective for six weeks. and need to be reapplied. Many people have told me that they didn’t think the corn gluten was as effective as the Preen but this is a decision that you have to make. Preen does now make an organic weed preventer from corn gluten. Whether this is an improvement on the corn gluten that was available previously I don’t know. Supposedly, the product features specially processed granules of corn gluten.
It’s important to remember that corn gluten is naturally high in nitrogen so you may need to adjust other fertilizer applications accordingly.
Other organic weed prevention options include adding a layer of mulch, installing landscape fabric or putting down a layer of moistened newspapers to prevent light from reaching the soil around your vegetable seedlings.