We put down fertilizer with halts in the spring. Several weeks later we see signs of crabgrass and other weeds. I presume I should use a post emergent crabgrass and weed killer at that point. And then later in the summer season put down more post emergent crabgrass and week killer. My question. Is this a normal routine for trying to control crabgrass and weeds in our lawn?
Hello - Mature crabgrass is very difficult to control and it's been especially tough this year. Some years are better than others. University research has shown that proper mowing (3-4 inches -- put your mower on its highest setting), fertilizing, and repairing bare spots are the keys to preventing crabgrass. In the spring, you can apply a pre-emergent for crabgrass control at around the time when forsythia plants are in bloom. You can make a second application 6-8 weeks later. Please refer to our webpage for current recommendations, https://extension.umd.edu/hgic/topics/crabgrass.
Also, here is information on lawn weed management in general, https://extension.umd.edu/hgic/topics/tips-lawn-weed-prevention-and-management
Now is the ideal time of year to fertilize and overseed cool-season lawns. A dense healthy turf is less susceptible to weed problems. See our turf maintenance calendar for fall fertilizing recommendations, https://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/lawn_pubs/HG11....