By Kim Ellson
During the warm days we just had, I was out looking at the gardens. I'm not sure just how and when it happened, but weedy grasses have invaded the beds. There are grasses among the iris rhizomes, grasses climbing all over the hosta bed, globs of grasses with peony stems sticking out of it, and grasses showing up out of the ground covers. And all of it is still green! How do I get rid of this mess? Is there something I can spray?
Answer
Time and time again we find ourselves caught off guard by that very first flush of weeds. How can it be that weeds are flourishing at a time when we dare not even contemplate gardening, the weather is so unfriendly? The answer is a simple one, what you have are cool season weeds or winter weeds. Cool season annuals actually germinate in late summer or autumn when temperatures are below 70 degrees. The newly established plants then enter winter in a vegetative state. Annual bluegrass is one of the most common of these weeds. It is a non-native European species that is a prevalent weed in both turf and landscape beds. It can be annual or perennial and many times people might even have a mix of both. Species like bluegrass ideally need to be controlled in the autumn prior to winter as by early spring they have already formed seed. Even if you are particularly diligent and weed those beds in early spring, chances are they have set seed and by pulling the plants you are spreading the seeds. If you can get out there early enough to pull the plants prior to the seeds developing, be sure to remove any weed plants so the seed is not deposited in your beds. In future try to be vigilant in late summer and autumn and pull the seedlings as they emerge. If you have only a small area I would always recommend hand-pulling rather than reaching for chemicals. Be aware however that this is something you will have to repeat annually as seeds continue to germinate. If you decide that the area is too large to hand-pull or perhaps it is too difficult to extract the grass from in-amongst your perennials, go ahead and apply a narrow-leaved herbicide in the spring once plants are actively growing. Narrow-leaved herbicides are selective and will not damage your broadleaved plants. Be sure to use herbicides responsibly and spot treat grass patches rather than making broad applications. To reduce the re-occurrence of bluegrass apply several inches of mulch to the bed. Alternatively a pre-emergent herbicide can be applied to the soil in late summer or early autumn to prevent seed from germinating.