what kills weeds and crabgrass but wont harm my lawn?

Answer 1

You need a systemic weedkiller specifically designed for broad leaf plants.

Answer 2

Killing Crabgrass With Preemergent Herbicides
The lawn weed, crabgrass (Digitaria spp) is a warm-season annual weed, which means it reproduces by seed. People often ask me how to kill crabgrass. The short answer: applying preemergent herbicides at the right time is the best way to kill crabgrass
To get rid of crabgrass (see pictures at right), it helps to know its life cycle. When spring soil temps (at a depth of 2"-3") reach 55-60 degrees Fahrenheit, the first crabgrass (also spelled "crab grass") seed will germinate. From mid-summer to fall, crabgrass produces seed. The crabgrass plants (but not the seeds) are killed by frosts in autumn.

Preemergent herbicides (also spelled "pre-emergent") come in either granular or liquid form and kill crabgrass seedlings as they germinate.
Think of preemergent herbicides as forming an invisible shield across the soil surface that stops emerging crabgrass dead in its tracks. This shield image will serve as a reminder not to practice core aeration on lawns after applying preemergent herbicides, since doing so would only "puncture" the shield. Aerate lawns beforehand, instead.
There are many different types of preemergent herbicides for killing crabgrass. "Weed and feed" products often contain preemergent herbicides, although some question whether their concentration is strong enough to be effective. I will focus on 2 preemergent herbicides: Dimension and Tupersan
Dimension (active ingredient, dithiopyr) is safe to use on most lawn grasses (check label first) and provides long-lasting coverage -- an important consideration, since not all crabgrass seed germinates at once. Thus Dimension will kill later-germinating crabgrass, too. Dimension also displays some effectiveness as a postemergent herbicide.

Tupersan (active ingredient, siduron) is worth mentioning because, unlike other preemergent herbicides, it will not damage germinating lawn grass seed. In fact, its active ingredient is often combined with starter fertilizers. Alternatively, for newly-seeded lawns, wait until after 3 mowings (or 3 months) before applying preemergent herbicides.

But do I really need chemicals for crabgrass control?" you ask. The answer is, No. While the best way to kill crabgrass is with preemergent herbicides, the best way to control it is by having a healthy lawn. Here are some ways to promote lawn health -- at the expense of crabgrass:


Fertilize (compost is fine) more heavily in autumn than spring. By autumn, frosts will have already killed any crabgrass.
Don't let bare spots remain uncovered for long, else opportunistic crabgrass will take root. In the fall, fill in those bare spots by overseeding.
When irrigating the lawn, water more deeply and less frequently. Crabgrass is a notoriously shallow weed.
Mow "high", leaving the lawn grass at a height of 2 1/2"-3". This will allow the lawn grass to "protect its own turf" better, depriving crabgrass seeds of the light they need to germinate.
A great organic "weed and feed" product is corn gluten. It will suppress crabgrass germination, while fertilizing your lawn.

Don't forget good old weeding as a method of crabgrass control. Hand-pulling small patches of crabgrass before it goes to seed makes eminent sense. To facilitate weeding, water the lawn first (weeds are more easily extricated from wet soil).

Answer 3

We use Weed and Feed in the fall. It took out all the crabgrass and clover and fertilized at the same time.

Answer 4

You should try vinegar. Put it on the weed, let it soak in. You need to give a couple tries. It will work, and it is cheap, and environmentally sfe. It also works good as a laundrey addative instead of fabric softener (no there is no smell) and a disinfectant in certain conditions. Good luck! check ou this link for more info!

Answer 5

There is a product called weed b gone that you hook up to your hose and just spray it on your lawn....the stuff is awesome. About a week later, you notice yellow in your lawn, and when you look closer, you see it is all the weeds, and no grass!

Answer 6

It depends what kind of grass you have, I work with bermuda and fescue. If you have broadleaf & grassy weeds in Spray it as if your were painting the area rather than shooting it into spots.bermuda, you could mix" msma & weed b gone" with a little soap in a hand can or backpack sprayer. Spray it as if your were painting the area rather than shooting it into spots.There may some temporary yellowing of the turf, but the grass comes out of it and the weeds die.. Use the labeled rate.

Answer 7

The best way is to pull them before they release seed. If they pop up again use glyphosate- roundup typre weed killer!
Eventually they will die out or until a gust of wind transports seeds from other places to your garden or lawn.

Answer 8

There's a lot of products that you can find everywhere, I use the "weeds be gone" by Scott's and it really works if you do follow the instructions.

Answer 9

Just go to any garden center store (home depot, lowe's included) and they'll have several options.

I like the fertilizer 'Weed n' Feed'.

Answer 10

Scotts weed-n-feed works great. You can get it in the hose attachment or seed bags