If you recall, I wrote one of my first blogs was about the invasion of Japanese Stiltgrass in our area. It is, in fact, choking out more and more of our native plants than expected. I took one of my pictures behind someone's house where the stilt grass has taken over. We may be getting frustrated with it in our own lawns, but it is also becoming more of a problem than it looked this spring.
As a reminder, this annual grass goes through its entire lifespan in one year's time. It is now reaching the end of it's life but it has spread its seeds getting ready to start growing next year. Soon, the existing plants will die back and leave a nice brown patch in your lawn as well as on the perimeter of the woods and deeper into our natural spaces. You can see it all over Reston's paths.
Springtime is a the best time to control this very adept annual grass. This past year, I personally used Preen which is a pre-emergent annual weed control for crabgrass and numerous other weeds. It needs to be spread BEFORE the weed germinates for its year of terror! The best point of reference is to apply it when the Forsythia is blooming. Since Preen has an effective life of 3 months, you will need to REAPPLY in the June timeframe. Both my neighbor and I realized that the Japanese Stilt Grass has a second germination period because it appeared in both of our yards in the June/July time period.
Also, since Japanese Stiltgrass is an ANNUAL grass, you can safely apply Preen to your flower beds where you have perennials planted. As I mentioned back in the spring, the major active ingredient for Preen is Corn Gluten. This ingredient is very popular in annual weed control. If you do not want an "inorganic" product like Preen, there are "organic" versions available"WOW! Supreme a Pre-emergent Weed Control and Control and Fertilizer" that is heavy on corn gluten for weed control.
Since it is now the Fall, you need to plan ahead but act NOW! It is time to fertilize your lawn and reseed. This needs to be done BY October 15 to be most effective. Even though you may think Spring is the time to do this lawn work, when planted in the Fall, the roots of the new grass seeds can become established before the onset of winter. Then, when the warmth of Spring comes up on us, the grass should not die off and it will hold on to the rains a bit more.
Time to tackle your personal lawn crises by seeding now. Water. Put down a pre-emergent weed control in the Spring and again in early Summer. Keep watering. Your lawn should be nice and free of Japanese Stiltgrass next year! Fingers crossed for you (and ME!) as we tackle the maintenance of this aggressive weed.