Thursday, May 19, 2011

Gardening Thursday – Protecting Your Plants, Part 1

To keep this from being so long, I’ve broken it into a general discussion and spring plants for this week and summer plants for next week and I’ll cover both diseases (Ds) and pests (Ps) in both - but it's still kind of long.

One of the worst gardening feelings is seeing my hard work go down the tubes at the hands of Ps or Ds. Since different parts of the country have different issues, once again, I’ll have to stick with my area. I try to be as organic as I can but I live in one of the country’s worst areas for both disease and pests – Zone 7, the transition zone, where hot moist weather provides a great environment for the nasty’s. Therefore, I do what I need to do to ensure a good return on my time and money investment.

Generally pests can be controlled by prevention, mechanical or chemical means and diseases by prevention and chemicals. By mechanical, I mean covers, traps, companion planting, etc. and chemical can either be organic or non and prevention means taking the necessary steps to prevent plant infection by the Ds.

My approach is to use a combination of all of these and often on the same plants – for example mulching, staking, and keeping the leaves dry on tomatoes plus removing infected leaves and spraying with a fungicide for disease prevention and practicing crop rotation.

When using any chemicals it is critical to read and follow the directions and use those that will deal with the pest and are okay for the plant. Around my area, Sevin (carbaryl is the generic name) is the universal pesticide but it is not effective on all pests and should not be used under certain conditions – so again read the label.

For the spring plants, spinach, asparagus, radishes (maybe flea beetles), onions, and peas have very few problems so I do nothing to protect them - although I may see some beetles on the asparagus later on and use a chemical to get rid of them.

Other spring plants are not as fortunate – Brassica’s (cabbage, broccoli, kale, etc), lettuce, other greens, and potatoes for example.

The main problem for the brassicas is cabbage looper worms – the inch or so long ones about the color of cabbage. I find the best way to deal with them is floating row covers which is a light weight spun fabric that let’s water and sun through, but stops the little white egg laying moths you see flitting above these plants - one source is Gardens Alive, but I get mine locally. Row covers can be used for any plant that does not require bee pollination to make a crop.  The covers need to be put on as soon as the plants go in the ground to be sure it’s early enough, but if you’re late like I was this year, the plants can be sprayed with the organic Bacillus Thuringiensis - Bt or a chemical fertilizer as if the covers were not being used. This is the result of being late.

The covers can just lay on the plants (floating), but I like to use half-moon hoops made from wire I had left over from a drop ceiling installation – I can see and pick the plants better. The cover needs to be pretty tight to the ground and I smooth the soil with a narrow leaf rake to aid in this. I anchor it with 3” long U’s at each hoop made from the same wire.

The main problem for lettuce is snails and slugs and they can be dealt with by trapping, such as in beer cups, where they drown, spreading Diatomacious earth (ground up fish skeletons), which they won’t cross, or bait which is very effective but must be used carefully as dogs will eat it and it can be fatal.

Greens can have the same issues as the brassicas plus flea beetles which leave tiny holes all over the leaves.  They are unsightly but rarely fatal (except on small eggplants) once the plants have lots of leaves - I control them with chemicals or don't worry about them.

While wire worms may occasionally eat into my tubers and flea beetles like the leaves, by far the bigger concern is the tenacious and voracious Colorado potato beetle – the larva can strip a plant of leaves overnight. While I’ve not tried it yet, floating row covers might work so long as the beetles don’t emerge from the ground under the covers – a good reason for crop rotation - and while potatoes do bloom, pollination is not required. I use the chemicals listed for them and rotate the types to prevent immunity development by the beetles. Potatoes may also get some Ds such as the same blights that infect tomatoes which are controlled with fungicides (potatoes, tomatoes, peppers, and eggplant are all in the nightshade family).

Here's the menu for the publications dealing with Ds and Ps in the home garden, including 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 Colorado potato beetle and tomato wilt problems.

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 for issues 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.
All photos can be enlarged by clicking on them.

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

One year ago:  Asparagus and Fried Grits



  1. Good information Larry. As you know, I had a fungus problem with my tomatoes last year, so went directly to the link. Not sure I found the exact descriptiom, but will look further for Colorado situations.

  2. Good ole zone 7.... George has grown roses in several areas of the country and definitely says that this area is the hardest one. First of all our ground is SO rocky. Then there is the crazy weather... Then D's and P's..... He does a great job --but has to use things like Sevin to keep the bugs away and Liquid Fence to keep the deer away.... Not an easy place to be a gardener.

  3. This isn't about a veg. garden, but I was wondering why my smoke tree died. Two years ago it was beautiful..full of smoke. That fall half of the tree started to die. We cut the dead part off and prayed that it was ok. The next spring, the half that was still there got leaves and smoke. At the end of summer the other half started to die. This year it was completely gone. The leaves and smoke turned brown and it was gone.
    What could have caused an otherwise beautiful tree to just die? The tree was only about 5 years old. Thank youy for any help. I would like to get another one, but don't know if I want to spend the money just to have it die. Judi Conrad, Bremen, Ohio.

  4. Anonymous - Without seeing the tree, it's difficult to say but some things that can affect trees are drought, chemicals put on the lawn, mulch up against the trunk (encourages pests and disease) vs. back a few inches. Next time, call your county agent as soon as you have the problem and they should try to solve it for you.

  5. I lost virtually my whole garden last summer to bunnies and deer. The year before, tomato blight got all of my tomatoes. It was sad. I'm hoping things will go better this year.

  6. Nice segment Larry.
    My biggest problem up here has been tomato worms. Easy enough to deal with but then again I don't usually grow leafy veggies.
    No garden for me this year so I'll garden vicariously through you!

  7. Larry, We love your energy and passion for your garden and food in general... Tastes great too! Take Care, Big Daddy Dave & Laurie

  8. Good info! I am going to tell my daughter about Diatomacious earth for her slugs and snails. She lives in Northern Cal and the weather is perfect for lettuce and greens and snails and slugs. What a great organic remedy!


I appreciate and enjoy your comments