Tasha,

You're going to get mixed responses with this, but the vast majority of people will discourage you from using chemical weed control in your planting area if at all possible. I'm one of them.

My suggestion to you is the same as to others. I pin down landscape fabric. It will eventually (sooner than you think) kill anything under it that needs light and not to be cooked by the sun. I have to go snap a shot of the progress in my own plot this year, but if you see that, it's all fabric, lol.

There's just a lot of risk using chemical plant control in your garden.

Cheers,

-Rathos

Personally, I use black plastic, as its both cheaper than landscape cloth but does a better job overall, IMHO, of keeping out weeds. Many weeds will grow through landscape cloth if they can get a foothold. Depends on the circumstances, of course.

However, to answer the OP's basic question, Preen and similar products (like the Miracle Grow one) CAN be of limited use in vegetable gardens if you want to cut back on the weed problem.

Keep in mind, Preen and similar WON'T kill existing weeds, and they won't stop regrowth from the roots of perennial weeds such as quackgrass, dandelions, Japanese thistle, etc.

Preen CAN be used safely around larger transplants, those with at least 3-4 sets of true leaves, and generally at least 4 inches tall. Provided, of course, you follow the directions and don't O.D. the soil with too much Preen. Same of course, for direct-sown plants -- its GENERALLY safe to use over the top of them AFTER they're about 4 to 6 inches tall. Unfortunately, though, for a lot of crops, say carrots or parsnips as one example, a bed can get awfully weedy by the time they crop is big enough to safely apply Preen.

You CANNOT direct sow seeds into treated soil. There are ways around this. One rather effective way is to treat the garden, then dig a trench a minimum of 4 inches deep and 4 inches wide (or however wide you want the planting row/bed/block to be) and backfill with clean, sterile potting mix, then sow seeds into that. You can also do individual planting "pockets" at least the size of a 2 gallon nursery pot, of clean soil to plant into for crops that grow in hills or clumps.

Preen type products will cut down but not eliminate the growth of many species of seed-grown weeds. So, you will still have some hand weeding to do. Some weeds will come up and die in Preen-treated soil. Others, such as some of the Lepediums (penny cress) will, in my experience, remain stunted but live out their life cycles, including producing seeds. Some weeds are relatively immune to Preen, such as Japanese Barnyard Millet, which seems to be stunted for a month or so, then grows out of it. Preen will reduce both the size and number of most weeds, but you will still get some.

Finally, in my own personal experience, I find that the "organic" version of Preen (corn gluten) doesn't do much of anything. Others have had success and like it -- it may depend on factors such as soil chemistry, weather, and species of weeds. I do buy and use the regular Preen on beds where I cannot use black plastic or other mulches, such as strawberry beds, iris beds, etc.

Tasha, you said .... 'I have a few weeds starting to pop up'.

I would recommend you get a hoe, a hand fork or just use your hands and remove those 'few' weeds to the compost heap. If you keep on top of them as they appear they will not get 'out of control'. Patrol and pull as soon as you see them. Don't let them seed. Getting out the herbicides is overkill. Little and often is the secret of beating the weeds. In time you will reduce the seed bank and you'll find yourself having to go searching for weeds to pull. I understand from your other posts that you're a new gardener and maybe you've read that weed killers are necessary. I've had my allotment for over 20 years (about the same size as your garden) and have never needed to use chemical weed treatments on it. I use cardboard mulch and hand weeding. And that's in a climate where weeds grow 12 months of the year.

Mulch...2-3" minimum...good start, many options.

Agree with Flora. While they are used in commercial agriculture, weed preventers and weed killers have no role in a home vegetable garden - no matter what size it is. The negative issues associated with them far outweigh any possible benefits from their use and a 70x19 foot garden is easily maintained with mulching and a hoe.

Dave

The corn gluten certainly isn't chemical, but it also in my experience doesn't work. I tried it in my asparagus bed, where hoeing isn't really possible, and the weeds laughed so hard they cried.

I love RoundUp/glyco...

It's a shame there's been so much of it dumped in fields non-stop that within a few decades it will probably be marginally effective rather than very effective in some areas.

Want to find RU/glyco resistant grass? Check out areas near commercial planting fields to see it or the beginnings of it, even in home yards. The resistant weeds are already well chronicled.

If it was used more responsibly we could enjoy it for far longer than it's current expected life span. It's as heaven sent for those that are physically limited as much as it is for some farmer needing to prep 1000 acres.

Some people will never like the stuff, but the amounts used in the home garden as a pre-emergent prep are believed to be generally harmless.

I've been considering putting newspaper down and covering it with soil? I feel like I need a last ditch effort- the bed that I want to do it in was left by the prior owner (as opposed to the ones I built), and even pulling every day I can't keep up with the weeds....

What does the label say about using on vegetable plants? I can't seem to be able to bring up a readable label on line.

I assume that this is a pre-emergent herbicide, correct?

je suis - have you thoroughly dug the bed with a fork before planting anything in it? That way you can get out the roots of perennial weeds which simply pulling won't find. A weed infested bed needs very thorough digging before use, preferably including a period left for regrowth and re digging before planting.

It is so tempting to get planting asap but time spent on preparation is never wasted.

Heres an image of the label:
http://www.scotts.com/smg/products/Miracle-Gro/plant_food/all_purpose/pdf/GWP.pdf

Have you read the label? Especially the part about use around vegetables? Note the restricted list for the vegetables it can be used around? Note the very different application rates based on type of soil? Note the application time of 10 weeks prior to planting?

Given the restrictions and the need to apply it more than 2 months before planting and that the goal is to grow vegetables in the garden why would anyone even consider using this?

Dave

Here is a link that might be useful: Label link

I use newspaper covered with straw. Works very well. A few Bermuda poke through from the bottom but they are pretty easy to pull if gotten early.
Prior to building each bed I lay down cardboard or newspaper in very thick layers.

I would just suck it in this year and pull the weeds, if you want to use chemicals do that in the fall.

I had/have Creeping Charlie on the edge of my garden. I pretty much ignored it till it started taking over the lawn and was getting to be a serious problem in the roses.

I waited till fall, got out some hose end weed killer and sprayed it on, very carefully around flowers.

It is not gone but better than ninety percent is.
What is left I can pull.

I just pull mine by hand but for a bigger garden like yours I'd probably go with the hoe, possibly after running a tiller down the rows if wide enough.

Personally, I'd feel better/safer about eating the produce from a garden that had been hoed rather than having weed killers applied. That's me though.

Doesn't hoeing also help keep the soil loose and aerated?

One disadvantage to hoeing vs. mulching is that it exposes weed seeds to the light, giving them a better chance to germinate - resulting in more weeds to be hoed. I like pinestraw for mulch. In a particularly weedy spot, a layer of cardboard under the pinestraw works great.

You can get pinestraw in Massachusetts?

susan2010 - that's one of the GOOD things about hoeing :) You cut off the seedlings as soon as they appear. Then you do the same for each new flush thereby gradually reducing the seed bank. I don't advocate hoeing instead of mulching, they are both good techniques. But when you are dealing with a fine tilth seed bed for direct sowing it's quick and easy to hoe down the rows. And in slug/snail country mulch can actually be counter-productive IME.

I know a lot of people like to push organic marketing, however, I've used pre-emerge herbicides for years.

Discouraging the use of herbicides around the garden is far from "pushing organic gardening". The two issues aren't even related.

Herbicides have their role in landscaping, commercial agriculture, and horticulture, no doubt, but the issue with using them around the vegetable garden is the damage to the plants you WANT to grow, not the herbicides themselves.

Every year both the tomato and pepper forums are inundated "what is wrong with my plant" posts with pics of plants damaged by herbicide use. And no it is not just from spraying. Herbicide damage can also result from using mulch that has been exposed to it.

Dave

@Flora- no, I didn't dig it out this year. Partly because I did in the fall of 2010, and I still ended up with tons of weeds that I never could really get under control. This past October, I put garlic in about 2/3rds of the same bed, and it didn't even occur to me that I needed to "prep" it (this is my second year gardening) and with the unusually warm winter nothing really "died". So that's why I was thinking about using newspaper.

I am abashed to say that I order pinestraw from pinestrawdirect.com. I really like working with it (it's "clean" and stays where you put it, lasts a long time, and smells nice), so I splurge. A bale goes a long way for me.

I frequently find bags of very clean needles from either White, Austrian, or Scotch pine trees along the roadsides in the fall and spring when people are doing yard cleanup.

Honestly, I have to laugh at them, to think they are throwing away perfectly wonderful mulching material, and often replacing it with something they purchased at Home Depot or Lowes.

But, their loss, my gain. And yes, I can sit there and pick out the stray pine cones and twigs if I don't want them in there.