Amaze as it has a much broader spectrum and last up to 6 months.

Here's my strategy, see what you think. Clear the ground of trash and sticks, etc. Trim up any small shrubs or perennials so you can see what you're doing. Take old newspapers and make a pad with 7 layers of newsprint. Starting at the outward edge, begin layering sections of pads, like you're shingling a roof. Overlap the pads so that it's not easy for soil to wash under the edges. Do not put the newspaper right up next to shrub trunks or perennial crowns. Next, mulch at the proper depth with material of choice. Next, sprinkle the Preen over the mulch, keeping it from staying on the leaves of shrubs or other plants. This helps keep perennial weeds from coming up and starving them of light. The Preen helps prevent blown in seeds from germinating. You have to reapply the Preen after 3 months, by the way. The newspaper will degrade over a single season, but by then it's prevented many weed seeds from germinating. The earthworms like it too! If you do this regularly, weeds become less and less.

Preen is excellent for weed prevention in shrub borders and flower gardens; the label indicates the (relatively few) plants which don't like Preen nearby. Preen is applied on top of the mulch, bark, pebbles or whatever is covering the soil. If not rain is forecast, the label advises you to water it in. It is widely available in the US in both small bags and a large plastic tub. Here in the Southeast it does not last the whole growing season; I usually put it down 2 to 3 times a year. I have extensive gardens at home and also care for shrub borders and a huge public rose garden. It is very effective against weeds which grow from seed. I spend almost NO time weeding, I couldn't take care of all these gardens without Preen! The only weeds I still have to pull in my gardens are oxalis and wood violets which sprout from tubers, rain lilies which sprout from tiny bulbs, and nutsedge, a weed grass which sprouts from a tiny black nut which is usually 6 inches or more underground. So we still have hand weeding to do, just not NEARLY as much. HOWEVER you will not be able to get any flower seeds to germinate in the areas where you have treated, so you may end up eliminating charming things like foxgloves, columbines and morning glories that you may be used to seeing magically appear every year. Preen even has a formula specifically for the Southern U.S.-- the big box stores often don't stock it just the regular stuff. Preen cannot be used in a vegetable garden, but you try cornmeal there. Get a small bag from the grocery store and if it works under your soil conditions, find a feed store and buy a big bag. Remember that wherever you put the cornmeal you won't be able to grow any new vegetables from seed until it completely breaks down. There is a cornmeal product called Concern; if you can look up the label info online it will give you guidance on how to use. I'm no help there, I get all my veggies from the farmers market! There are other pre emergents packaged for the professional; one of these is called Snapshot. No doubt there are others. Just remember that pre emergents are for prevention, not control of existing weeds. Preen does not kill weeds.

Postpone the seeding and concentrate on the crabgrass first. Crabgrass only germinates in the spring, but you can grow grass from seed any time. Most pre-emergents for weeds will also prevent grass seed from germinating. http://www.garden-counselor-lawn-care.com/pre-emergent.html