R. Wayne Mezitt: Getting to the root of the problem
Every experienced gardener knows this fundamental weed management principle: Remove weeds before they produce seed!
By mid-summer, many weeds are forming their seeds, so timing is critical. And this year their maturity is accelerated by the warmer-than-normal weather. But experience has taught me that the situation is not always as dire as it may first appear; I’ve learned to focus my weed management attention on those weeds that generate the best control advantage.
The herbaceous perennial weeds are my main concern because they get stronger each year they are not controlled. Annual weeds also can be a problem, but because their roots die back each winter they are more of an annoyance (albeit often unsightly!). Some biennials (germinate the first year and produce seeds the next) act a lot like perennials.
Surprisingly, some of the weeds that are the most prolific seed-producers tend to be also the simplest to remove. As a rule, I prefer to use physical (as opposed to chemical) weed management techniques. Many larger perennial (and biennial) weeds have simple or tap-roots that pull or dig out readily, enabling an efficient clean up of large areas. Some examples: Evening Primrose, Queen Anne’s Lace, Bull-thistle, Garlic Mustard, Pokeweed, Cocklebur, Dandelion, most brambles and some of the Goldenrods. Make sure you remove the entire root – any segments left behind can re-grow to become even stronger.
Other perennial weeds like Witch-grass, Mugwort, Canada Thistle, Bindweed, Yarrow, Clover, Wild Garlic and Giant Reed are significantly more difficult to control. Their root systems are more complex, often stoloniferous and readily break apart, rendering them far more tenacious and best managed in combination with chemical herbicides. Given my time constraints and the fast-advancing season, I leave these challenging types until I can devote better attention to their specific management.
Even the easier-to-remove types require resolve (and a strong back), especially when they have grown large. I prefer to weed during the cooler times of day and move quickly through an area, trying not to become distracted by the smaller and less critical weeds. Once weeds finish flowering and begin to form seeds, many have the ability to finish developing viable seeds even after they are extracted from the soil. So I always remove them from the garden to a compost area where they will be less apt to be a problem.
So many of these mid-summer days are so hot and humid – hardly conducive for heavy outdoor work. Inevitably some weeds will mature before I can pull them out. But making visible progress getting rid of some of those easier types is certainly gratifying, even if I know I’m unable to finish everything!
R. Wayne Mezitt is a 3rd generation nurseryman and a Massachusetts Certified Horticulturist, now chairman of Weston Nurseries of Hopkinton and Chelmsford, Mass. He has served as president of the Massachusetts Nursery and Landscape Association, the New England Nursery Association, and the American Nursery and Landscape Association, based in Washington, D.C.