For those who prefer weed-free lawns, spring grass care is as much about weed prevention as it is about fostering healthy lawn growth. Novices to spring grass care are often surprised to learn that not all lawn weeds are battled in the same manner. Depending upon whether a weed is an annual or a perennial, you will use a preemergent herbicide or a postemergent herbicide against it.
Spring Grass Care Tip #6: Applying Preemergent Herbicides
If you know that you have a problem with the annual weed, crabgrass, then fertilization in spring should go hand in hand with the application of preemergent herbicides. As their name suggests, preemergent herbicides address weed control not "after the fact," but before their seedlings can even emerge. Preemergent herbicides accomplish this by forming something of a "shield" that inhibits seed germination. Don't undertake the core aeration task discussed on Page 1 after applying preemergent herbicides: to do so would be to "puncture" this shield, thereby decreasing its effectiveness.
Crabgrass begins its assault on lawns in spring, when its seeds germinate. In fact, my suggestion on Page 1 that overseeding be carried out in autumn, rather than spring, is based in part on the threat posed by a spring crabgrass invasion. "So why not just begin by killing the crabgrass first with a preemergent herbicide?" perhaps you ask. Well, the trouble is that most preemergent herbicides work against not only weed seeds, but grass seeds, as well!
You can appreciate the dilemma here. Overseeding is incompatible with the application of most preemergent herbicides. Yet, faced with competition from crabgrass in spring, you may find it difficult to establish your new grass. So while it's still possible to overseed in spring, it's simply easier to do so in fall. There will be no competition from crabgrass then, because the fall frosts kill off crabgrass.
If you must overseed in the spring, look for a product called, "Tupersan." Unlike other preemergent herbicides, Tupersan will not damage germinating lawn grass seed. But if you're committed to staying away from chemicals altogether in your spring grass care, postpone overseeding till fall.
Spring Grass Care Tip #7: Applying Postemergent Herbicides -- Or Pulling Weeds
Keep an eye out for the emergence of the perennial weed, dandelion during the spring season, unless you find the presence of their cheerful yellow flowers in your lawn desirable. At the very least, you'll want to snap off their flower stems before they produce seed. If you're more ambitious, you can dig them out by the roots. Spraying dandelion weeds with postemergent herbicides is more effective in fall than in spring. If you do choose to spray, select an herbicide for broadleaf weeds.
Besides proper spring grass care, there's more you need to do to get ready for a summer filled with lawn mowing. Don't neglect preparations concerning the lawn mower itself -- the subject of Page 3....