Organic Gardening Tips TBT

Organic Gardening Tips

Excerpt from the January 2011 IOGA Newsletter By Janet Glover

Tomato Blight

2009 was a terrible year for tomato blight, and I used both Soap Shield and Neem oil. As you may know, Soap Shield is made from a natural copper fertilizer and a fatty acid that give the plant protection from fungal disease...and it decomposes to a soluble copper and fatty acid, both of which Gardens Alive says are used by microbes and by plants. And they do use a very low amount of copper in their formula. I used both Soap Shield and Neem oil in 2009 as a preventive and after I saw blight starting. I have to say that the blight was still devastating, though we were able to help the tomatoes struggle through the summer. We did end up with quite a few tomatoes from the eight plants, but the harvest was spread out...with just a few tomatoes at a time. It took quite a while to can enough tomatoes to last through the winter! It's hard to say how much the Soap Shield and Neem oil helped because I don't know what would have happened if I had not used them at all. But they definitely did not stop the blight in 2009. At most, they only helped the tomatoes to just barely make it through the summer.

This year, I read about Plant Guardian, which is a bio fungicide...Bacillus Subtillis...that attacks harmful bacterial and fungal garden diseases. So I began using Plant Guardian, along with Soap Shield and Neem oil, as soon as we planted tomatoes because I was concerned about a repeat of the awful blight we had in 2009. I do believe that the Plant Guardian is what has made the difference since it's the one thing that's different than what I did in 2009. As I said...the Soap Shield and Neem oil together didn't stop the blight in 2009, but this year, our tomatoes have been very green and healthy, with no blight. Recently, three of the plum tomatoes were hit with something that appears to be fungal, but it hasn't really spread to the other plum tomato plants in that bed. We did take out two of the plum tomato plants because they were nearly dead, but the other plants are growing and producing very well.

So...I'm not sure exactly what did hit those three plants. It seems to have been a matter of them wilting overnight in the heat and then not recovering...and perhaps that weakened them and made them more susceptible to disease. I did use Plant Guardian on them right away, and one has recovered fairly well...and the other two were taken out yesterday. The rest of the plants have a few yellowed lower leaves on them, but nothing serious. We will remove the leaves and continue with Plant Guardian and Soap Shield and Neem oil. I would like to have a test plant somewhere separate from the other tomatoes so that I could use only the Plant Guardian on it...just to see if it would do as well or even better than the plants sprayed with Soap Shield and Neem oil. And I plan to do that next year. In any case, I think I can say that the Plant Guardian has made a BIG difference this year. Our second bed of tomatoes has done very well and does not show any signs of blight.

We planted five tomato varieties, Sweet Olive, Early Girl, Better Bush, Better Boy, and Mountain Spring, all

purchased from Whole Foods. Oh...and we also have one bed of only Roma plum tomatoes. We do love heirloom tomatoes, but they seemed to have less resistance to blight, and so we began trying varieties that are VFN resistant, and that seems to have helped. Next year, I want to try heirlooms again, to see if Plant Guardian will make a difference with them. I would like to use no sprays at all...not even the safer organic ones...but with tomatoes, it seems that there is no way to get around it. Blight quickly takes over if we leave them untreated. But I think Plant Guardian is safer...so hopefully my experiment next year will show me if I could raise tomatoes using only Plant Guardian. I'll let you know how that comes out! With gardening, I think our motto is always "Next year..."

Potatoe Blight

Potatoes go hand-in-hand with tomatoes as far as disease, since both are susceptible to blight and other fungal diseases. We've had potato problems this year and in 2009, and I read quite a bit about that online. I buy only certified organic seed potatoes from Seeds of Change, and this year we planted German Butterball and Red Sangre. Both started out beautiful, lush, and green, but then one bed began turning yellow. We're very careful to rotate beds on a 3-5 year schedule with tomatoes and potatoes, so I knew it was not because potatoes had been planted there before. I read as much as I could find, and I believe it may have been verticillium wilt   which I learned can still be present in

seed potatoes, even if they are certified virus-free. Though it didn't make sense that the seed potatoes had been infected, because only one bed started turning yellow. And no potatoes or tomatoes (or peppers or eggplant) had been planted in that bed before.  so it was

really a mystery as to why the yellowing began. And I may be mistaken about verticillium though that is the

only answer I could come up with. Perhaps it was actually blight, and I just didn't realize it. I began using Soap Shield, Plant Guardian, and Neem oil on that bed and on the other two beds of potatoes. I do believe that it was the Plant Guardian that made the difference.

Soap Shield and Neem oil together did not really stop blight on our potatoes in 2009 but when I used Plant Guardian, I did see the potato plants make a partial recovery.  They would begin growing again, and the new growth was green. They would really "perk up" after an application of Plant Guardian...much more than with the Soap Shield and Neem oil. And I do think Plant Guardian gave the other beds of potatoes some protection so that they were able to stay healthy several weeks longer...though eventually, all three beds did succumb to whatever this is...blight or verticillium.

Truly, it looks like blight now...though I cannot be 100% sure of that. I do think from all that I have seen that Plant Guardian has given the most protection and has helped most when the potatoes were diseased.

Again, I think I will plant a test potato bed somewhere next year using only Plant Guardian...to see how it does. I really do feel better about using Plant Guardian than using Soap Shield, even though Soap Shield is a safe product. So I am going to experiment and see what I find out!

Oh...for those who may not know...Plant Guardian is safe to use right up to the day of harvest, and it can be used at any time of day--in heat or high temps--and will not burn or damage plants in any way.

Squash Bug

Yes, I use Pyola (from Gardens Alive--phyrethrin from pyrethrin daisies mixed with canola oil) for squash bugs and for Japanese beetles and cucumber beetles. It does kill squash bugs, and the label says it kills the eggs, though I have found that I need to keep a close eye on the squash and cucumbers once I find squash bugs.

While the Pyola does kill the live squash bugs, I have also found more of them later...so I think the eggs did hatch out. We do go through the bed and remove all leaves that have eggs on them...and those leaves are destroyed. But I have found that squash bugs are so persistent that I have to keep a very close watch on them. I try to use the Pyola very carefully...even though it's a safe botanical remedy...because it will kill beneficial insects, too. So I spray judiciously...only on the exact area where I know there are squash bugs.

We didn't have too many Japanese beetles this year, though they did attack the basil, as they always do. With that, I just use tulle from the fabric store to cover the basil so that the beetles can't get to it. It works perfectly, and no Pyola is needed. We want to make floating row covers for more of our crops...such as squash and cucumbers...to hopefully keep squash bugs and cucumber beetles out. Even though Pyola is safe...I still would rather not use it unless absolutely necessary. If we can cover the plants to keep bugs away, then we'll definitely do it. That is something we'll work on a lot more next year.

Powdery Mildew

We've had powdery mildew on cucumbers the in 2008 and 2009, though it's been fairly late in the season when it started. Really, we had gotten most of the harvest before powdery mildew set it...and we continued to get lots of cucumbers even after the mildew made the plants look fairly ugly.  I did use Soap Shield and Neem oil in 2009 for powdery mildew and I think it did hold it off somewhat...though it did not stop it. This year I've used Plant Guardian, and I haven't seen any powdery mildew on the cucumbers. Though I have to say that the cucumbers look awful for another reason...that small groundhog that dug under the fence the one night that the electric fence shorted out!! The groundhog ate at least half the leaves off the cucumber vines, and that really damaged the plants. They have looked awful since then...I think some sort of disease set in because of all those open wounds where the groundhog ate the leaves.  The plants have produced, but not very well, so I planted a second bed of cucumbers...and it looks just fine. No powdery mildew or other problems, and we should get cucumbers from it later this month. I'm using Plant Guardian as a preventive, and so far it's looking good. I didn't do too much preventive spraying on cucumbers in 2009. Mostly, I sprayed after powdery mildew had set in. And this year I didn't have a chance to worry about it since the groundhog created havoc with the cucumbers!

Our basic thought on sprays is to use them only when really needed...and then very carefully and judiciously. And we are trying to go without them whenever possible. We don't mind living with a small amount of insect damage, as long as it doesn't destroy the plants. The BIGGEST problem by far is a fungal disease...and that is mostly the problems with tomatoes and potatoes...blight, verticillium, etc. For that, it seems that spraying is a necessity...but we use only safe sprays from Gardens Alive...and I really prefer the Plant Guardian...and I think it has given the most help and most protection.

Tomato Hornworms & Cabbage Loopers

Oh...we do use Bt as well...Bacillus thuringienses...to keep tomato hornworms and cabbage loopers out. But we use that very carefully, as well, because it will kill butterfly caterpillars too. And I have read that there is a concern that butterfly numbers are declining in areas where there is overuse of Bt. So I am very careful to use it sparingly...and only directly on the plants where caterpillars are a problem. Really, it seems that I need to use it only once or twice, and that takes care of it.

We don't have any problem with tomato hornworms, and we did have them in the years before I used Bt. But a little of it does seem to do the trick insects, not leaves.