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sfbaysteph

reseeding in SFBayArea, will crabgrass actually die?

sfbaysteph
9 years ago

Hello there!

I have spent an embarrassing amount of time reading absolutely everything I can get my hands on about reseeding my (super tiny, but it's MINE!) lawn, and I'm off to a good start, but I have a few questions.

back story: I screwed up and dethatched and seeded with an inferior seed this past spring.
I've learned my lesson and have spent most of this summer eradicating crabgrass, mostly by hand (lawn is only 330 sq feet)

and? I have an awesome tan and some pretty good looking triceps now!

A week before Labor Day I couldn't take it anymore and I did add gypsum to the lawn and shampooed it in. I then dethatched again and added a nice amount of compost that I raked in.

I used Jonathan's seed and it is now quite lovely. I have been pulling the random crabgrass that is still peeking out by hand, and then I drop in a few grass seeds in the hole.

I am not able to get out ALL of the crabgrass roots when I am pulling in the morning ----sometimes it rips up my new sprouts, and sometimes it just breaks in my hand.

I'm probably spending about 30-45 minutes a day pulling crabgrass, but I can visibly see a difference which is what is egging me on.

my questions:

it's been 3 weeks since the seeding and it's mostly fescue that is coming up. The Kentucky hasn't sprouted yet but I'm beginning to get dirty looks from dog-walking neighbors when I go out to hand-water. Due to the drought.
(we have no water restrictions in our city, and every morning there is a nice layer of dew on the grass)

So I'm watering in the super early morning and at night so I don't get dirty looks.
I'm a wuss, what can I say....

1) Is that okay? Is the morning dew and only 70-degree weather good enough for the seeds to stay damp?

2) Will the grass seed grow over the crabgrass roots that I can't get out and smother it?

3) since it never freezes where I am, will this crabgrass EVER die?!?!?!

4) since we don't really have seasons, what is the best time to add the preemergent crabgrass killer this spring? Is it Memorial Day? later in the year? should I do it twice?

thank you for any and all help ---- I never ever thought that I would be so into my lawn, but I'm finding it to be a completely relaxing and wonderful part of my day to go out and check on it.

even if the neighbors do think I'm completely bonkers....

Comments (16)

  • sfbaysteph
    Original Author
    9 years ago

    I just wanted to follow up --- I ended up spraying weedbgone with crabgrass killer today on the lawn because I found this huge section and I got completely discouraged.

    and now the city HAS decided to restrict water, so the patches with seed might just sit until we get really heavy dew or actual rain.

    I'm bummed.
    I really wanted to figure this out on my own-- my husband just wanted to yank it up and put in sod.

    anyhow, does anyone happen to know if crabgrass will die in an area that doesn't freeze? we do get a tiny bit of frost on rooftops in January, but nothing really in the fall.

  • sfbaysteph
    Original Author
    9 years ago

    I'm posting again to bump this up the thread.
    I am not able to find an answer to my crabgrass problem and locally can't find anyone who understands what I'm looking for.

    The lawn I seeded at the end of August looks great but is still quite overrun with crabgrass. I did spray weed b gone but it's really not making a dent.

    We are due for some rain, finally, and the weather is definitely dipping overnight which creates a nice amount of early morning dew.

    In an area that doesn't freeze, will crabgrass did out? When should I add a preemergent? The only one I can find locally is Halts.

    Thank you!! My friends and husband are tired of hearing me talk about the lawn! :-)

  • sfbaysteph
    Original Author
    9 years ago

    Hi again, I was hoping for a bit of insight into my crabgrass and I wanted to provide a bit of an update.

    I reseeded in late Aug with a mix of fescue, rye, and Kentucky (Jonathan's Ultimate Black Beauty) and it has come in nicely, although I think it's mostly the fescue and rye that I'm seeing. I am still having batches of crabgrass which is bugging me an awful lot.
    I am hand-pulling and spot treating with Weed B gone and it looks like I'm getting the upper hand.

    I'm annoyed at the drought because I wasn't able to water the way I wanted to in order to keep the Kentucky wet enough for a full 3 weeks. Now that the weather is a bit cooler I just put out 100% (99.95 it says) KBG seed in the few shallow spots and threw out another few handfuls just for good measure.
    The local water guidelines stipulate that I can only water between 6pm and 10am. Before today's seeding I was watering once a week after the fescue filled in for about 20 minutes, which due to our high water pressure passes the tuna-fish-can test.
    But now I've thrown out new seed --- can I get away with hand-watering with a watering can with grey water from the sink/baths mid day in the few dirt spots with seed I've got, or will the grey water be bad?

    will the crab grass EVER DIE?

    we are looking at 50-60 degree nights with a lot of morning dew (I can accumulate water from the gutters) and about a high of 75.

    thank you!!

  • morpheuspa (6B/7A, E. PA)
    9 years ago

    Sorry, I missed this the first time around.

    Crabgrass dies at frost...which you don't get. So no, the stuff is going to hang out until it gets old and dies. I have a suspicion that your crabgrass is an annual, so it should only live a year or so, but that's not reliable.

    Not to mention the seeds being dropped through the period, which will happily sprout when damp enough. Whenever that is.

    Manual control will work for now, and you can't spray with new seed in. Later on, try some Weed B Gone with Crabgrass Killer. That stuff works.

    Watering seed with slightly soapy water is just fine and shouldn't cause a problem. If it had anything but soap in it, avoid use. I've never tried using nothing but gray water, but it should be OK.

    Once per day watering is a little trim for seed, so I might think about topdressing those spots with some peat moss (available at any landscaper, garden shop, and most big box stores), completely finished compost (ditto), or even a quarter inch of a good potting or top soil (ditto). That'll help hold some moisture in.

    Since it's gray water, you can probably get away with more than once per day watering in those spots. It doesn't take much, just keep them damp. But maybe they've actually put restrictions on gray water usage as well?

  • sfbaysteph
    Original Author
    9 years ago

    Thanks, Morph.
    I can water anytime between 6pm and 10am. The dew stays on the lawn until about 11am (in shade until about 10 or so) and then the sun goes down right around 6. I think I can keep everything moist with a bit of grey water if I go out at 2 and 4. I did add grass clippings to the spots where I reseeded handily and stirred in some compost. Peat moss is a good idea, thank you.
    I was thinking of adding wet coffee filters, too, but the neighbors (and my kids) already think I'm kind of wonky.

    We've been having a high of about 75-80 right around 3pm which is awfully high for us, so I don't anticipate it lasting even another 2 weeks.

    Thanks for confirming my thoughts about the crabgrass -- I will continue to pull it and now that the grass is much thicker it is no where near as prevalent.
    I'd LOVE some sort of frost to hit and kill it all off though! ;-)

  • morpheuspa (6B/7A, E. PA)
    9 years ago

    Skip the wet coffee filters, they're too solid for the young sprouts to get through. Spent coffee grounds, however, would be just the ticket to hold some moisture (plus slowly feed the new sprouts and attract worms like nobody's business).

    If you can manage to keep the seed moist with all that, great. We tend to recommend twice a day watering (minimum) to make sure the seed is always internally moist. A dry outer coat isn't much of a problem.

    But if you mulch, the seed holds water much longer and much better.

  • beckyinrichmond
    9 years ago

    Steph, I don't have the answers for you but just wanted to advise that weedkillers like Weed B Gon can harm young grass. I used preemergent twice in the spring and it worked great for preventing crabgrass. Be aware that if you use a preemergent you will not be able to plant grass for a certain length of time (4 months for the kind I used). Read the labels on any herbicide. Some can't be used if the temperature is too high, some can only be used so many times a year, some can't be used on baby grass until it has been mowed so many times. Read the labels.

    Morph, what do you think of Tenacity as a possible crabgrass killer for her? I don't have experience with it but a lot of people are using it with new grass.

  • morpheuspa (6B/7A, E. PA)
    9 years ago

    >>Morph, what do you think of Tenacity as a possible crabgrass killer for her? I don't have experience with it but a lot of people are using it with new grass.

    I don't have any first-hand experience (no crabgrass), but people do seem to like it for that, and the damage is extremely minimal.

    I'd still wait until the third mow of the lawn just to be sure.

  • sfbaysteph
    Original Author
    9 years ago

    This is so helpful, thank you! I've got a coffee filter a day I can put out on the site, then -- great! should I keep the grounds in, too, or discard them?

    I must admit I'm not the best composter, I usually forget about my pile and it completely dries out, but if I could simply throw handfuls of spent grounds out on the lawn and it would help attract worms, I'm happy to do it!

    Thanks, Becky. I haven't used a preemergent before, but did buy some that is sitting in the garage until spring. I like your idea of putting it out twice since the crabgrass is so invasive and never really dies out. I am hoping that the new grass is super thick by then to help crowd it out, also.
    If I put it out in late March, is that the right time? and then again in May?

    is it weird that I'm dreaming about grass? wait, don't answer that...
    ;-)

  • beckyinrichmond
    9 years ago

    Here in Virginia, pre-emergent for crabgrass is applied when the forsythia blooms, which is usually in March. I think it relates to a certain soil temperature. I did my application in middle March this year and again in early May since I knew I wanted to overseed in September. Read the bag; it should have information on how often you can use it.

    Don't put coffee filters on the lawn. Morph said "skip it." You can put the coffee grounds on the grass. Dump the grounds into a container and fling them outside. The filter can go in the trash can or compost pile..

    On Tenacity, it's something you can use with baby grass. However you have already used Weed B Gon on it, twice in spots, and the grass doesn't need another stressor right now. Hopefully the crabgrass is dying and won't bother you again until seeds want to sprout. And then the pre-emergent could go into action. You may want to ask around about when is the best time to use pre-emergent for your area.

  • sfbaysteph
    Original Author
    9 years ago

    Thank you, Becky, I appreciate this help!
    I'll continue with what I'm doing and will do the preemergent in spring and then again in a few months to get the late crabgrass.

    I don't have anybody IRL to talk grass stuff with since we're the only ones without gardeners. And incidentally, our lawn is now definitely one of the better ones!
    The gardeners around here aren't all that knowledgeable-- more of a mow and blow crew.

    We have a nursery that's pretty well respected a few cities over and I'll ask about tenacity, thank you.

  • beckyinrichmond
    9 years ago

    Here's an article from UC Davis on crabgrass in CalIfornia. Looks like you should mark your calendar for March 1 next year to put pre-emergent down. Don't worry about Tenacity. It would have been a better choice for you when you were spraying in September. If there is another time when you want to plant seed or have baby grass and want to fight weeds at the same time, remember it then.

    Here is a link that might be useful: article

  • sfbaysteph
    Original Author
    9 years ago

    this is fantastic, thank you!!

  • dchall_san_antonio
    9 years ago

    Coffee grounds are a fertilizer all by themselves. You don't need to compost them.

    Coffee filters are usually non-biodegradable, so toss them.

  • sfbaysteph
    Original Author
    9 years ago

    thanks, dchall. I've been tossing the grounds out in the areas that are thin the past few days. I'm happy to use them up!

  • morpheuspa (6B/7A, E. PA)
    9 years ago

    It's a nice way of tossing one less thing in the garbage or down the garbage disposal. Unless you already food compost, in which case your composting worms are wondering where the heck their daily caffeine shot is.

    I've trained my mother (who drinks coffee, we don't) to enjoy her morning cup while flinging the spent grounds out over the lawn. It's not anywhere near enough to make a visible change over 12,000 square feet of grass, but it's also one less thing to throw out.