Questions about Grass Seed and Herbacides??

Question

I killed my entire lawn (well, really broadleaf weeds mostly) with Round up Herbacide last spring and after it turned completely brown, I ran a core aerator over the entire area and then spread out tall fescue seed and then starter ferlizer. I followed the recommendation for the amount of seed. And luckily for me, it rained every other day for 2 weeks after that, so I was expecting great lawn. However, I recieved about half weeds (different then before) which looked almost like crabgrass or dallas grass, maybe it was. So eventually when summer came , you know what happened. So I am stuck with a weedy lawn again.

Where did I go wrong? What should I do this year to get a nice lawn established?

Answer 1

The easiest and quickest was to a great looking lawn is to get sod professionally installed.

In the past, I have personally manually removed all broadleaf weeds (the best result for me and it lasted longer). It is best done when the weed is small and begins to flower (Flower=Seeds).You do need a chemical to get rid of crabgrass as it spreads through runners! So if you manually remove a clump of crabcrass you have to make sure you get all the roots! Which is a PITA.

Watch the quality of your lawn seed!!! Some brands have a high percentage of weed seeds.

Scotts has some great lawncare products that I recommend you do some research on - as they have pre-emergants and fertilizers with Crabgrass controls. I personally can't use those things so have discovered other alternatives. :)

Good Luck on your lawn this year!!

Answer 2

roundup (glyphosate) is not a selective weedkiller which is why the whole lot went brown. chances are you had some weed seeds in the soil, which were not affected by the roundup as it is only taken into the plant by the leaves. also what are your neighbours gardens like? its a never ending battle if you are surrounded by neglected meadows, because the seed will end up all over your lawn anyway. There may well have been weed seed in the grass seed also. unless you are planning many an hour of hand weeding or repeated pesticide application you might be better off keeping the grass short and tolerating the odd weed. Alternatively turf the lot with the most expensive seed grown turf you can find.

Answer 3

Round up kills the growing weeds, it does nothing for the weed seeds still in the ground. Now that your fescue is growing, use a pre-emergant this spring to deal with the annual weeds, the kind that you spread out with a push spreader and water in. This will prevent weed seeds from germinating at all. Then get the perennial weeds with the appropriate spray. Don't go getting it from WalMart, go to a real garden center and ask them for the best spray to use on a fescue lawn, and if you can take a few of the weeds to show them what you have, that'd be best.

Answer 4

Round up is non-selective herbicide which means it will kill almost anything it comes in contact with. If you bought a poor grade of grass seed there may have been some weed seeds mixed in (called chaff). If you were to use a pre - mergent, it needs to be applied in the spring when the ground temp is below 50 degrees. I don't know where you live, but here in Minnesota that would be early May. Also to keep your weeds down use a product with the active ingredient Trimec in it, and spray the weeds as they come up. Good luck
Tim

Answer 5

The weeds grew faster than the grass and over took it. You followed the seeding directions but you may wish to seed even heavier this fall and hope the grass will choke out the weeds. You can spot treat the weeds with roundup and put down a preemergent herbicide if your not going to add more new seed that is.

Answer 6

You also needed to put out a pre-emergence to keep the weed seed from popping up. But that would mean you have to lay sod down. Go to a good local garden store and they should be able to help you.