Green Side Up: Why it's important to know your weeds
I recently overheard a novice gardener say, “We don't need to know what the weeds are – just pull them all out!” Although I appreciate her enthusiasm she's setting herself up for a lot of unnecessary hard work. It is important to learn the weeds in your garden so you can most effectively deal with them. Once you start to familiarize yourself with the top “dirty dozen” or so weeds in your area it's easy to make decisions on how to deal with them. I listed what I considered to be the top ten worst weeds in a previous column.
For instance pulling annual weeds in the fall—after they've flowered and dispersed their seeds—may make the garden look tidier but it won't reduce the number of weeds next spring. I'd rather spend my fall clean-up time removing perennial weeds since I know they will be back with a vengeance next year.
It's useful to know that some weeds can be killed by hoeing just below the soil line. The plants can then be removed or allowed to dry up where they lie. However, don't try this with purslane! Every piece left touching soil will eventually form a new plant, and you'll have a bigger weed patch than you started with.
Other weeds, such as chickweed, disperse a prolific amount of seed into the soil which can be controlled using a pre-emergent herbicide. It's important to know your weed when using chemical controls because the type and the timing of the herbicide vary depending on the plant.
One of my tasks at Rotary Botanical Gardens is to maintain a cutting display which shows what is growing in the garden that week. Often I'll include a weed (I dub it “Weed of the Week”) and add information about its growth habits and control measures. It's a popular feature with visitors.
The UW System offers one good website for weed identification. I've also found good weed identification sites on Facebook where participants post weed photos and others will take a stab at identifying it. Finally, our county extension agency is always a good place to ask weed and pest questions. You can send your questions to [email protected].
Janice Peterson has worked as a grounds horticulturist at Rotary Botanical Gardens in Janesville since 2002. She is a master gardener with the Rock Prairie Master Gardener Association. Though her education is in plant science, she considers her love of gardening and strong back to be her true qualifications. Janice is a community blogger and is not a part of The Gazette staff. Her opinion is not necessarily that of The Gazette staff or management.