Weed control seems to be a never ending project for many homeowners. We often think that every weed is controlled in the spring. That is not the case as there are exceptions. Many people mistake little barley (Hordeum pusillum) for a foxtail because the foxtail and little barley seed heads are similar. However, little barley is a winter annual that comes up in late September – October and spends the winter as a small plant. It thrives in the cooler spring temperatures, forms seed heads and dies out usually by July. Foxtail, on the other hand, is a summer annual that does well in hot weather. Also, foxtail will not produce seed heads until mid- to late-summer.
How do we control this menace to the lawn? The best control for little barley is a thick lawn that is mowed high enough that sunlight does not hit the soil. Little barley seed will not germinate in such conditions. Over seeding in the fall can thicken up a tall fescue lawn and prevent a little barley infestation.
However, if you do not plan to overseed, preemergence herbicides can be used to provide at least partial control of this weed. Dimension (dithiopyr) is labeled for barley (Herodium spp.) which would include little barley and therefore can be used to keep this weed under control. Dimension can be found in several homeowner products including Hi-Yield Turf & Ornamental Weed & Grass Stopper and Bonide Crabgrass and Weed Preventer. Other products may contain Dimension in combination with fertilizer or broadleaf weed killers.
Because little barley is a winter annual that germinates in the fall, apply the preemergence herbicide in August and water in to activate. If over seeding, do not apply any preemergence herbicide as it will interfere with the germination of tall fescue.