Pre-Emergent Herbicide

[TomatoDon]

Or...as the farmers say here...premerge...Ring a bell PV? :wink:

Anyway, since we're dealing with established seedlings, can the tomato patch soil be treated/sprayed with a pre-emergent herbicide that will prevent weeds? I know...and I don't like chemicals either, but I am curious if there might be one of these new generation of organic type weed stoppers, germination stoppers, that is safe that we all might be interested in.

Thanks!

Don

[landarc]

My experience with preemergent chemicals is that they can be used with rootd cuttings with no ill effects in the landscape. The key is to make sure that the cutting is above the vaor barrier that they create in the top soil layer. I do not know about the new chemicals, but. the older ones worked by using either a herbicide, or very powerful fertilizer to create a vapor barrier of chemical in the top inch or two above and below the soil grade. Roots or leafes that entered into the zone of vapor would be burned by the fertilizer. This was why mulch made the chemical so much more effective, by holding the vapor.

Tomato seedlings should certainly be both deeper and shallower than the vapor area. If in doubt, run am experiment with a sacirifical seedling or two and see.

[travis]

Don,

I'll ask a farmer buddy of mine again ... but last summer, we were discussing tomato gardens, and he said he plants a small patch for his elderly mom each spring by first sprayin' the area along her fence with Roundup then pokin' the seedlings in a week or so after the turf is all burnt off. She just ties the plants to her fence and he says the weeding is minimal.

I'll ask him for details next time I see him later this month. We're on the SWCD board together and meet third or fourth week of the month.

PV

[TomatoDon]

That's what some of the old timers here tell me. Round Up can be stout stuff. But they say to spray, wait a couple of weeks, and you are good to go. I guess it does seem safe enough if you wait that long. But keep me posted on anything new you find.

Thanks!

Don

[carolyn137]

years ago I used to use something called, I think dachtal, or simuilar, but the minute the soil surface is disturbed, even by walking on it, it's of no use.

And it wasn't organic either. Actually I don't know of any organic pre-emergent weed killers but then I haven't researched this area at all, and I suppose Don, if you did some Googling you might come up with something.

A general Roundup spray isn't permanent either, before you put the plants in, that I do know. In other words, riffle the soil surface a bit and you've lost your barrier. And Roundup does break down with time as do most general weed killers.

And it;'s my recollection that dachtal and others were so so effective against annual weeds but not that good against perennial weeds.

The only method I saw that worked so so, which I saw for the first time after I moved upo here is to put down heavy layers of black plastic and let them stay on the ground for at least a year, and that seemed to cook to death the perennial as well as the annual weed seeds, for at least a season or two, and then back to the beginning since the seeds of those are readily wind dispersed from anything nearby.

[TomatoDon]

I guess I'm also thinking of these weed and feed granule types that prevent the weeds and fertilizes the stuff you want to keep. (Like the old AG 101 saying, "A weed is any unwanted plant." So, I guess a Brandywine in a corn patch would be a weed. )

I can't find anything of significance on web searches, maybe I'm not looking hard enough or using the wrong key words. I hoped there might be some time released granules that you could apply that would work all season, which I think they have for lawns. Heavy, heavy wheat mulch does good in tomato beds, but even that let's too much through eventually. At least in my experience. And I can't find a reliable source of it.

Good news on another front. I saw the first seed displays of the year at Wal-Mart today. Burpee. No Brandy Boys, though. Ferry Morse had a display in Lowe's here, too. This gardening stuff will be everywhere soon. The first sign of spring. Now...if I could just find some of that MetroMix 360. :wink:

Don

[MawkHawk]

Corn gluten works well as a premerge in my yard and will prolly actually be good for the soil. It's pretty cheap too, I think. It is a good alternative to chemicals.

[NCTIM]

Weed and feed is most likely not a good idea. I believe most weed and feeds contain a post emergent herbicide. The most common being 2,4-D. As Carolyn suggested, do google search using 2,4-D or whatever the active ingredient is and tomatoes as key words. Tomatoes are easily damaged or killed by 2,4-D even through indirect contact.

Last year I put out weed and feed on my lawn and then decided to plant a extra tomato or thirty. Knowing I had done the weed and feed thing I did some searching and discovered lots of info. My plants turned out OK but I ended up ammending the soil so much that I basically wound up with a raised bed of "potting soil."


Tim

[Rena]

As some of you may recall my whole tomato garden and yard was killed or stunted by weed killer. This was done by people we hire to spray our natural areas.
MY suggestions are to MULTCH the heck out of your area to keep down weeds and hire some cheap labor to pull weeds if you are unable. Just my 2 cents.

[landarc]

GARDENER! just thought I would add that for Keith.

I would be of the group that does little other than pulling to control the weeds, maybe a little weedfork work. I am too familiar with both herbicides and pre-emergents to fool with them in my garden. By the way, Roundup is a herbicide and not a preemergent. It will penetrate and kill the roots in a ground application. Also, most of these chemicals are labelled as not enduring in the landscape, but, my experience is that this is not true. By pre-emergent I refer to things such as Treflan et al. Carolyn is right that the minute you disturb the soil, the chemical efficacy is gone. These too can endure.

Truthfully, weeds are a natural part of teh environment and allowing a few to grow shouldn't be a huge problem and they do serve the process that KC refers to of mvoing nutrients through the soil column if they are allowed to decompose and returned to the soil.

[TomatoDon]

I was just curious and interested because I'd never used anything like that. Lots of opinions, but nothing stands out as really safe, truly good overall. It's true, there is nothing more reliable and proven than a good sharp hoe, mulch, and just old fashioned weed pulling. I use some cotton gin trash in my beds, and pulling weeds from that isn't too bad. It's the darn bermuda grass that creeps in that is is such a problem in mid to late season. I think I am going to hit the whole thing with Round Up a couple of weeks before I plant, though. The locals here swear by it, and PV seems to think it is ok, too. Will keep you posted.

Thanks for all the great input!

Don

[travis]

>>"I think I am going to hit the whole thing with Round Up a couple of weeks before I plant, though. The locals here swear by it, and PV seems to think it's okay ..."<< Don

Whoah! I didn't say I think it's okay, necessarily. I said a farmer friend of mine uses Roundup to kill the vegetation on his mothers tomato garden spot. Roundup is not a preemergent as has been pointed out. It's also not a ground sterilant.

Roundup kills the vegetation that it lands on and then binds up with clay particles in the dirt and becomes ineffective beyond the point of initial application.

I have never ever used Roundup in or near my garden. I do use Roundup in a small, 1-gallon hand pump sprayer to kill the weeds that grow in the cracks in my concrete driveway and out in the street alongside my yard. That's all I ever use it for.

All the farmers around here use Roundup on their beans and corn fields especially for no-till applications and post emergent on Roundup Ready soybeans. And they use it liberally around the farm to clean up fence rows and, like I said, to clean up their gardens before planting, etc. But farmers do a whole lotta things I would never do.

The highway department uses Roundup around guardrails, etc., but I do not allow them to use it alongside our regulated drains. And the only thing that goes on our regulated drain side banks and into the waterway is approved herbicides applied by licensed contractors. And that means "approved" for use considering the watered or dry condition of the ditch at the time of application.

I'm not adverse to the use of herbicides per se, but I would never use them in my own garden and do not use any pesticides in my gardens other than an occasional use of Sevin on a target plant that I purposely set aside to attract bugs for the killing ... then I don't eat or give away the fruit of that plant. And in my current garden, I've only had to do that once in 2005 due to a huge infestation of those yellow with black spots bug that infested my cukes then attacked my tomatoes.

The question in the OP was regarding chemical applications and I answered that with an anecdote. Sorry if I implied a recommendation.

PV

[TomatoDon]

No, it's fine PV. I know what Round Up does, and again, a lot of people use it for what you described. I don't use it around the garden, but may try it in a few beds this year a couple of weeks before I put my tomatoes in. I haven't heard any horror stories of doing it that way, and it seems safe. They say it breaks down pretty well and doesn't have harmful residual effects. I'm going to test it and see how it works for me.

Good hearing from you. I was over near the Delta today. Good weather here right now.

Don