Use corn gluten meal next year during the spring, that will keep all your weeds away.
Here's where I got the information...
Garden Plot: Tips for spring lawn care
by Mike McGrath
http://www.wtop.com/902/3580895/Garden-Plot-Tips-for-spring-lawn-care
Forget spring seeding; just get your gluten down
Joe in Hagerstown speaks for many listeners when he writes, "Now that we can actually see the grass again can you give us a time frame for when to seed bare spots, and when it's okay afterwards to apply corn gluten to prevent crabgrass. Am I right in assuming that once the grass seeds have germinated they can't be harmed by the gluten?"
Yes, Joe. But crabgrass germinates at a soil temperature of 55 degrees, while actual grass seed needs much warmer temps (closer to a toasty 70 degrees measured four inches down). So your crabgrass would be up and growing long before you got to the gluten.
Spring soil is just too cold for successful seeding. So stop the crabgrass instead by spreading corn gluten meal - the only natural pre-emergent weed and feed - next month. Hold off on any reseeding until August.
Soil temp countdown; still way too cold for crabgrass
It's time for your weekly update on soil temperature! As we have hammered at you for untold millennia, crab grass plants die over the winter, but they drop a lot of seed before they expire. Those seeds lie dormant until soil temperatures reach 55 degrees as measured four inches deep and then sprout to become the dominant weed in area lawns.
This invasion of the fescue snatchers typically occurs in April, just as forsythia and redbuds begin to bloom and when the water temperature in the Chesapeake Bay also approaches that magic number of 55. (Right now those temps are hovering around 40 degrees; here's the link if you want to keep tabs on the waters.)
Applying corn gluten meal just as we approach that magic 55 will prevent crabgrass germination, feed your lawn, and do it all well within the new lawn care laws in our area.
But don't jump the gun. The pre-emergent action of corn gluten only lasts for about a month, so you want to get your timing right. Once that crabgrass germinates, it's almost impossible to stop.
Why can't I sow grass seed now?
Michael in Herndon is one of a legion who writes: "My grass is a disaster. I want to tear it out and replace it. I've heard that the fall is an ideal time to do this, but would it be suicide to spread seed in the spring? I don't think I can afford the instant gratification of sod."
Sorry Michael, but your real-life choices are to be instantly and somewhat expensively gratified by that sod or to prepare to sow seed around Aug 15. By the time spring-sown, cool-season grass seed like bluegrass or fescue can (finally) germinate, the temps are getting too hot for the already-stressed, young and very weak new plants, which always wither and die.
Ah, but sow the same seed mid-August and the warm soil and steadily cooling temps virtually ensure a great stand of grass. The smart money says to just mow what you have at three inches high for now and plan for August. It'll be here sooner than you think.
Viable new lawn options for spring
In our last thrilling episode, Michael in Herndon wants a new lawn, doesn't want to pay the premium for sod and asks, "Do you really have to wait until August to sow grass seed?"
No Michael, you can spread bluegrass or fescue seed in the cold soil of spring where it will rot, lose vigor and feed voles until the soil warms up enough for germination (typically a month or so later), at which point it will be getting too hot for any frail survivors to ... well, survive.
Spring is a perfect time to lay sod, however. It's also the right time to install warm-season grasses like zoysia and Bermuda, which go tan dormant over the winter but otherwise do well here, especially zoysia, which is very low maintenance. Plant zoysia plugs in the spring and you'll have a full green lawn by August. Yes, it will go dormant in cold weather, but it won't allow any weeds to elbow their way in, will need very little mowing and will even fill in its own bare spots. It just won't be green for Christmas.
Peas on St. Pat's? Sure, if you cheat
Monday is St. Patrick's Day, the traditionally "lucky" day to plant your peas. However, the forecast suggests bad luck for traditionalists as highs will only be in the 30s, nighttime temps will be well below freezing and there's a chance of snow.
The best way to seize the proposed good luck involved and not grow pre-frozen peas is to cheat. (And remember, cheaters always win!)
Gather up your snow, snap or English shelling pea seeds, wrap them in moist (not sopping wet) paper towels, put the towels into a plastic bag, fold the bag over loosely (don't seal it) and check the seeds every day. When they show signs of sprouts, plant them outside if the weather has improved enough, stall for a few days more, or plant them a few inches deep in containers (that will give you another week before they need to go outside for sunshine).
Pea seeds won't sprout in cold soil, but pea plants will grow just fine in that same soil; the cold-weather loving plants can even take a couple of light frosts.