By Bev Johnson

Master Gardener

This is a $50 word that, roughly, means the study of the cycles and natural phenomena in relation to climate on plants. There is more to the explanation, but this is all we need for today’s lesson. 

Bunkey had more weed than grass last year and by fall, the crabgrass had nearly replaced the blue grass in his lawn. He tried 2-4-D, 2-4-5-T and was thinking about T-N-T, as nothing he tried had done much good. He actually had two problems, wrong stuff at the wrong time. 

The time to kill annual weeds like crabgrass is in the spring, just as the seeds begin to sprout. The problem is to know just when that is. You can try to determine if the soil is the right temp for the sprouting of the weed you are attempting to kill, or- you can let old Ma Nature do it for you. One of the definitions of soil phenology is the study of soil temperature’s affect on plants. Here is how you use this science to kill weeds. 

Put your first application of weed killer or corn gluten meal on when the daffodil buds first show color. The second application when the lilac buds show color. This happens only when the soil is the right temperatures for those plants to bud. It is also the time weed seeds start to sprout. 

If you put your chemicals on too soon, they will just deteriorate. Too late, or if it is too wet, the seeds have already sprouted. Water in whatever you apply, or it will not be effective. 

Now about corn gluten meal. This is a byproduct of cattle feed. Some bright farmer noticed that where he had spilled CGM, the grass was greener and had fewer weeds than the grass nearby. It took scientists ten years of study to get CGM to the public. Unlike chemical treatments, CGM can be applied year after year and only improves the soil as it is organic. It is the only treatment lake people should use as it will not harm the lake or it’s inhabitants unlike some chemical weed killers. 

GMC is about 10percent nitrogen. It reaches peak effectiveness in about 2 to 4 weeks and keeps active for about 2 to 4 months. It’s a really yukky color, almost orange. At 20 pounds per 1,00 feet, your yard will look like it has been sprinkled with the kind of cheese only found in boxes of mac and cheese. It is kind of an interesting look for a while. Makes your shoes orange too. 

Phenology is very useful for vegetable gardeners, too. Plant your spuds when the first dandelions bloom. Since you have applied CGM to your yard, you will need to watch the neighbor’s yard to determine when that is. Here are some more tips. 

Plant peas when the forsythia blooms. Cool weather crops, beets, carrots, lettuce, spinach, and cabbages when the lilac shrubs are in first leaf. Plant corn when the white oak leaves are the size of a squirrel’s ear. Use your binoculars. Beans, squash, and cucumbers when the lilac is in full bloom. The semi tropicals, tomatoes, peppers, melons etc. should wait till the iris is in full bloom. If the soil temp is below 55, they will just sit there and pout. 

To determine if the soil is warm enough, remove as many layers from your backside as the neighbors will tolerate, (bare is best). Sit on the soil for 5 minutes. If your cheeks are cold, it’s too cold to plant. Be sure to re-dress before you start to garden again. Nude gardening is dangerous.