You ever heard the old saying “you can’t win for losing”. I feel that way quite often now days. I think the same thing can be said for home gardeners. If it isn’t dry weather (or excessive …
You ever heard the old saying “you can’t win for losing”. I feel that way quite often now days. I think the same thing can be said for home gardeners. If it isn’t dry weather (or excessive rainfall), late freezes, insects, or plant diseases, it’s any of a number of other things that can damage plants in the home garden despite all the time and hard work that it takes to be a successful gardener.
This is the prime time of year when many of us are controlling broadleaf weed problems in and around our lawns and landscapes. It is also the time of year when most of us are getting those warm season vegetables established and growing in our gardens and colorful flowers planted and potted around our landscapes. Already this year I have had a couple plant samples brought into my office (they happened to be tomatoes but could have been any number of garden vegetable plants). Each of the samples had twisted up limbs and very distorted new growth. These are very classic symptoms of herbicide damage. Once you see herbicide damage in vegetables it is pretty obvious. In each case as I talked with the homeowner, we eliminated all the most common causes including spray drift, contaminated sprayers, etc. The one thing they had in common was the fact that they had used animal manures as an organic fertilizer (and don’t get me wrong I am certainly a fan of using such “stable manures” as a fertilizer product and soil adamant. Actually, I can never remember a time when there was so much interest in using organic fertilizers, etc. in the home garden. I’m not sure if it is the result of the extremely high price of nitrogen fertilizers or just the desire of home gardeners to get the added benefits of organic matter in their garden soil that has sparked the renewed interest in using organic fertilizers for home gardening.
Despite all the positive and very beneficial aspects of using such organic fertilizers, there is one potential drawback. That drawback is the potential for herbicide residue damage. Many of the common herbicides used to do broadleaf weed control in pastures, hayfields, and yes even home lawns are often not broken down during the digestive process in grazing animals and can indeed be passed along through manure and unknowingly incorporated into the garden if these manures are used as fertilizers.
Even grass clippings from the home lawn can still contain enough 2,4-D and related products to cause damage if these products were applied to the home lawn.
Tomatoes, peppers, sweet potatoes, and many other vegetables grown in home gardens are very sensitive to these herbicides and can be damaged at incredibly small levels. They can be damaged at levels very much lower than other less sensitive plants.
The product 2,4-D is one of the most common of all broadleaf weed control products for both livestock producers as well as home lawn owners and can stay active in manures for a relatively short period of time, up to about three months or so. Other more active herbicides such as pichloram and several other products, sold in a number of pasture weed control products, is another story all together. Pichloram can under the right conditions stay active for a period of eighteen months up to two years in amounts that can damage tomatoes and other sensitive crops (remember it takes only a minute and almost immeasurably small amount).
Once damaged by herbicide there is very little a homeowner can do for the affected plants. Some will die outright, while others that do not receive a lethal dose will seldom if ever fruit properly. In my opinion, damaged plants should be replaced (in another location) whether they live or not. There are a number of take home lessons to be learned. First and foremost is to carefully read and follow the labeled instructions of any weed control product used in and around the home landscape, pasture, hay field, etc. The use of organic (manure) fertilizers in the home garden certainly has benefits. Manures are a great source of nitrogen, phosphorous, and potassium (all vital plant nutrients) as well as much needed organic matter. If you are using such manure fertilizers; however, make sure that you know the source and make sure to find out if herbicides such as 2,4-D or pichloram have been used in and around those pastures. If you use home compost, be careful not to use composted clippings from herbicide treated lawns in or around your vegetables, bedding plants, etc.
Finally, be very careful about using herbicide products around your garden and landscape. While herbicides can be necessary and very useful in taking care of broadleaf weed problems, they can have some very unintended results. Plants do not have to be directly sprayed to be damaged, as in the case of the manure. Herbicides can also drift, so absolutely avoid spraying on windy days. Many products such as 2,4-D can also volatize (turn to vapors and become airborne) especially on warm sunny days. Also make sure that you have (and label) a separate sprayer for herbicides apart from the sprayer you use for insecticides or fungicides. Herbicides are very difficult to clean out of sprayers, especially if you are spraying very sensitive plants such as vegetables.