If you get the Preen for veggie gardens - see link here - there is no need to wait before planting your transplants and you can reapply multiple times during the growing season. All you need is for your transplants to be at least 2-3" tall and have their second set of true leaves. Preen only affects seed germination and root development - it has no effect on existing weeds or growing plants.

FWIW, most gardeners will avoid any weed block like the plague. It doesn't have much effect in retarding weed development and it does impeded good water penetration and gas exchange, as well as preventing any granular ferts or applied OM (compost, etc.) from working into the soil.

Thanks Gardengal - I guess what got me confused was Preen's statement FAQ about young plants. FAQ: "When can I sow seeds or transplant plants after an application of Preen® Vegetable Garden Organic Weed Preventer?" Response: "Six weeks from when Preen® Vegetable Garden Organic Weed Preventer was applied" From the same site previously linked to. I was thinking about Lumite - not solid black plastic - for the reasons you mentioned.

Even woven weed block fabric can be a handicap in the garden. It doesn't need to be a solid plastic - the exact same concerns apply.

I tend to agree the world isn't perfect. Of course, I also know there are many state extension offices that suggest using woven fabric block in the vegetable garden.

"Also, I'd also like to transplant through a permeable weed block, which I also use to warm the soil. any thoughts?"

I'll pass on the Preen use part of your question as I garden organically.

There are a number of previous discussions here about the pros and cons of various plastic-based mulches the search will pull up for you if interested. As gardengal said using it isn't a really popular option and I agree completely. But some of its drawbacks depend on (1) where you live and your local climate, and (2) what specific crop?

In other words while it may work okay for northern gardeners in cooler climates, those in southern warmer climates can have real issues with the soil heat it generates and can trap. And while it may be of benefit for heat-loving crops it can be detrimental to other crops.

An example if I may: many swear by its use with squash and melons, supposedly has several benefits. So I tried one 4x50' row of a similar woven product this year in my climate. 1/2 the row are summer and winter squash plants and the other 1/2 melons. I ran 2 50" soaker hose under it spaced 2' apart (and boy am I glad they are under it rather than on top).

I now find that not only do weeds poke through (although far less than there would be without it of course) but I am having to water that row substantially more often and for longer periods of time. The plants are much more prone to wilting and mid-day heat stress than the same plants in another row mulched with straw. So much so that I am now planning to spread straw on top of it to block sun.

Production is also down on that row by comparison although that may be simply from the difficulties of feeding them vs. the other row.

No scientific claims but IME so far it hasn't proven to be beneficial over plain old straw mulch and detrimental in some ways.

Dave

Yes, I actually do live in northern climate, but I forgot to mention I plan on putting straw (not hay since I understand that can bring weeds) on top of the weave once the soil begins to heat up. But, that brings up a question regarding Preen. is the corn gluten based product, which I believe they mark as organic not considered to be organic, just curious about that?

Please forgive the double post. I forgot to mention yes I live in the north so have a rather limited growing season thus the need for the black weave. I am careful not to torn product get mixed into the soil. Also, I garden in a community plot so I have limited control over the plot as I regularly have weeds thrown into the garden so I pretty much need coverage year round. Having a limited growing season the last thing I need is to have straw on top of near frozen soil. And I do have to go through a two step process of starting with the black weed barrier and then adding straw as the temps heat up. It would be nice, of course, to just use straw but it's necessary to try and extend the season to maximize the season. So there really is purpose behind madness. :) Hopefully, this helps explain things a bit.

Yes it does explain things a lot. You have several trikes working against you so in this case you have to make the best you can out of the situation. Good luck.

Dave

Aptz (and others)- I have been using a generic corn gluten for the last several years when I plant my onions, and in the early spring on my new garlic plants, because they are so difficult to keep weeded. I am not using Preen, either the regular or the organic type, because of the cost. While I am not weed free, it certainly makes it easier to hand weed the onions and garlic. In the rest of the garden, I use a scuffle hoe around plants and till the large open areas that will eventually be covered by the vining crops. As you know, keeping the weeds knocked down before they develop seed heads will certainly reduce your weeds going forward.