Thursday, May 26, 2011

Gardening Thursday – Protecting Your Plants, Part 2

A Maine pond.

By far, the biggest challenge in dealing with pests (Ps) and diseases (Ds) comes in the warm months when both flourish and use my garden in support of their reproductive cycle.  My plan for this post, which could be a month long, is to hit the highlights for the crops that many home gardeners grow - tomatoes, peppers, beans, corn, cukes, and squash.

In our area, fungal diseases (early & late blight and anthracnose) attack tomatoes, beans, potatoes, peppers, and cucumbers and they are all treated the same way. The key to success is prevention and once a leaf or branch has the disease, it cannot be cured and must be removed from the plant and disposed of away from your garden. Fungal diseases, like other fungi, such as mushrooms, propagate via tiny spores that can be in the ground or the air and grow in warm moist areas – such as plant leaves.  When working with plants, such as tieing tomatoes, it's best to do it when the leaves are dry to avoid spreading any fungi with your hands or tools.  To avoid the heat, I do mine in the evening and if I know my plants are infected and I'm removing those branches, I continually wipe my hands and tools with Chlorox Wipes from a pop-up container.

For me tomatoes are the most susceptible and I spray them with a listed fungicide every Saturday and following a rain. I also remove any leaves that contact the ground and mulch with straw to prevent soil from splashing on the leaves during rains. I never water over head, which wets the leaves, I make sure enough foliage is removed from multi-stem caged plants to allow for air circulation and leaf drying, and I inspect them daily and remove any infected leaves. It is still a major issue for me and can quickly kill the plant if left alone. I don’t have as big a fungal problem with the other plants except beans which get the same spraying as tomatoes if needed.

Another normal problem with tomatoes and peppers is blossom end rot which is not a disease but a calcium deficiency. While I add gypsum as a source of calcium at planting time, the most common cause of the problem is allowing the plants to get so dry, they cannot bring up the calcium which is dissolved in the soil moisture.

Corn can also be infected by blight and rust fungi and are treated the same as the others.

From a pest standpoint, I have several to deal with, but the Colorado Potato Beetle is the most difficult especially since it preys on all four of my nightshades – tomatoes, peppers, eggplant, and potatoes. I pick off the adults when I find them, but once the larva appear, I resort to a listed insecticide as they are voracious eaters.

The squash vine borer (SVB) is my biggest threat and it kills the plant by hatched eggs out on the plant making their way back to near where the stem emerges from the soil and boring a hole into the inside. From there, it eats the stem inside until one day the healthy looking plant you had yesterday is dead today. I spray the entire plants with a listed insecticide until blooms develop, then I spray the first couple of feet of stem and ground once a week thereafter, as prevention is the key. Once the borer gets into the stem, it is pretty much doomed.

Aphids can be a problem, but aren’t much of one for me and when I’ve seen them, they were usually being dined on by Lady Beetles.

Flea Beetles are a problem for me as they eat small holes in the leaves that can actually kill the plant, especially small young ones. They attack my potatoes, but usually after they are too big to inflict serious damage, but they are out in mass, when I plant my eggplant. If I don’t spray them with a pesticide the day I plant them and keep them sprayed, I will get no eggplant.

Finally there is the corn ear worm which craws into the developing ear and begins feeding as the kernels develop, usually eating the top few rows. When developed, they bore a hole and exit to become a moth – so the hole you see is the exit, not the entrance. I’ve tried everything from mineral oil to chemically spraying the silks to spraying the entire plant and I still get them. I’ve discussed this with a local grower of sweet corn and he advised they spray theirs every few nights with permethrin (pyrethrin is the naturally occurring product made from chrysanthemums) and I’ve found very few worms on the many ears we’ve bought from them. As a kid, nearly every ear I shucked (this was my job) included a worm and if I were selling it to today’s urban-raised society, I’d have to prevent them, but since it’s just for me and they don’t eat much, I do nothing to prevent them.

Other than aphids and potato beetles, the other pests I see on my tomatoes are the horn worm and stink bug and you just need to inspect your plants regularly to find them. If you find an area missing significant foliage, start looking for the hornworm. While they are about the size of a little finger and extremely ugly, they blend in with the plant very well and can be hard to find, but you need to look until you find one as they can eat a lot of plant in a short time. You’ll know stink bugs are feeding on your tomatoes when you see little yellow spots on the tomatoes that are white when you remove the skin. I control them by spraying if they get too bad.

The big pest for beans is the Mexican Bean Beetle and I deal with them by chemical spraying if they begin to significantly harm the plant. They will become obvious as the little yellow larva eat the underside of the leaves and leave a nearly see through skeleton.

For more info and a picture on any of these just do a quick web search and remember, the later the year goes, the worse they nearly all become.

The following is copied and amended from last weeks gardening post.

Here's the menu for the publications dealing with Ds and Ps in the home garden, incluging trees, schrubs and lawns - a real wealth of info - from University Of Tennessee Extension. Since I'm dealing specifically with Ps and Ds control in the vegetable garden, here are the specific manuals for them:

Disease Manual - the back of this manual has controls by crop by pest.

Pest Manual- the back of this manual has controls by by crop by pest.

Then there are also many specific manuals such as these for the Mexican Bean Beetle and Foliar Diseases of Tomato.

One source for organic products is Gardens Alive.

The Extension manuals cover most common garden pests and diseases, but your State Extension Service will have them specific to your area. If you do any type of gardening or landscapping, I strongly urge you to get familiar with the available publications for your state extension service - learning about their existence may be the most important thing I got from my Master Gardener training and the most important thing you'll get from my blog.

My garden is coming along.

All photos can be enlarged by clicking on them.

Have a great day and thanks for stopping by Almost Heaven South.

One year ago:  Escape To Serenity Falls



  1. Your garden is so lovely! I can use some of these tips. Thanks.

  2. I just expect to find one of those darn worms every time I shuck an ear of corn. The garden looks graat Larry.

  3. Your garden is huge and, having read your post, I must say you are a far more serious gardener than I had imagined. I can picture the wonderful meals that comes from that plot. I's no wonder you never speak of boredom :-). It is huge and takes some tending I hope you have a wonderful holiday. Blessings...Mary

  4. I hope we escape the tomato blight this year; I'll try your technique of cutting back on foliage and see if that helps. Gotta plant this weekend!

  5. We have the same problem with tomatoes here. Once the warm months of summer arrive so does the humidity which is our worst enemy. I should try your spraying schedule.

  6. Alexis totally agrees that she can learn a TON from your Thursday posts.


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