Entries in organic gardening (4)


An Organic Solution for Plant Disease and Harmful Insects

A rich fungal smell is in the air. In my area during late May and June, plentiful rain and increasing humidity promote all sorts of plant diseases and harmful insects. Blights, black spot, anthracnose and powdery mildew afflict previously pristine leaves. Colonies of aphids and whiteflies feed voraciously on succulent plant juices. If I want to have a healthy garden, I have to spray.

Most diseases in the garden are caused by fungus. As an organic gardener, I try to prevent the problems by spraying with neem oil, which reduces disease and kills harmful bugs such as mites, scales, aphids and whiteflies. Oils have limited or no affect on beneficial insects. Neem oil is a vegetable oil pressed from the fruits and seeds of the Neem tree. I immediately remove any diseased leaves when I see them, and I start spraying with a neem oil solution toward the end of May and continue to spray weekly through June, or until I don't see new disease or colonies of whiteflies and aphids. I also use neem oil in late winter as a preventative and to kill fire blight, a bacterial disease that causes the leaves of plants to wilt and to appear as if they have been burned. Fire blight overwinters on branches, twigs, and trunks.

Sometimes I use a horticultural mineral oil, which is effective for similar problems (although neem oil appears to have better fungicidal properties, probably because neem contains sulfur-like compounds, which have their own fungicidal properties). There are two types of horticultural oils. Dormant oils are used as a preventative in late winter or early spring when the weather is cool, while all-season oil can be used during the growing season also. Always read the labels. Most horticultural oils cannot be used during very hot weather. I use an all-season oil. I spray during the cooler parts of the day, and I avoid spraying any good guys such as bees.

I don't spray everything in my garden, but I always spray vegetables and fruits.Unfortunately, I must spray to keep my tomato plants healthy. I also have a ligustrum hedge that has chronic disease problems, and it has done much better since I started spraying it a couple years ago. Otherwise, I monitor all my plants and spray particular plants at the first sight of trouble. 

More organic products for garden management are becoming available because of increased public demand. All products should be used according to directions. Misused, even organic products can be harmful.

The best defense against disease and harmful insects is to plant healthy plants that are less susceptible to begin with and to plant them where they can thrive. Right plant, right place! Good horticultural practices, such as appropriate watering and mulching, are fundamental. Using compost and other organic products that feed the soil will promote a healthy underground ecosystem and long term good health. Artificial fertilizers give a boost to the plant but do nothing for the soil. In fact, artificial chemical fertilizers can build up salts in the soil that drive away earthworms and other helpful soil dwellers.  

Artificial chemicals can ultimately harm the garden. Artificial chemicals aimed at killing harmful insects or treating disease will also kill beneficial insects. This is becoming a huge problem. We need the good guys, and over 90% of insects in the garden are good guys. This insect made a tasty meal for a wren in my garden.Plants have immune systems; if you use artificial chemicals to treat your plants, you run the risk of damaging the plant's natural ability to fight pests and disease. The plant becomes weaker and more prone to damage.

It is also important to clean garden tools with isopropyl alcohol to prevent spreading disease from one plant to another. I keep a spray bottle of isopropyl alcohol in my shed along with other garden products.


For more information on keeping the garden healthy, check out these additional posts: Steps to a Healthy Garden.



Have you ever proceeded into a project, only to be conquered by frustration?

I generally avoid synthetic fertilizers and pesticides. I like to use methods and products that support the health of the whole eco system. I want any animal or child to be safe to play on the grass. Did you know that 1 in 3 dogs will come down with cancer? We gardeners often are concerned about protecting our plants from dogs and other critters, but instead it is more likely that our domestic pets or desirable wildlife such as birds, butterflies and bees will be harmed by chemicals we use on plants in our gardens.

For years I have used an organic weed and feed type fertilizer, whose primary ingredient is corn gluten. I applied it to the lawn with a drop spreader twice a year, and I have been happy with the results. 

Nevertheless, it was not available locally, so I had to pay a high shipping fee on top of the cost of the product. This year I determined to buy a local alternative. It was easy to find a good organic fertilizer, but the pre-emergent was harder. Finally I located a corn gluten product designed to be applied with a hose end sprayer. That seemed easy, and it was on sale! I bought a couple of bottles.

I had been happily applying the product for about fifteen minutes when I realized it was not being sucked up by the delivery system. I put the bottle down and went to turn the hose off so I could investigate the problem.

This outside faucet is original to my old house, and when I turned the faucet handle to shut it off, the thing exploded. I gasped as water hit me full in the face, and then I stood in shock under the geyser spraying out into the yard. 

Husbands are good for this sort of emergency. Lou shut off the water to the house, then was able to cap off the broken faucet. It was late in the day and I was soaked, so I decided to wait till the next morning to finish the corn gluten application.

A new day. It was gorgeous! I made a mental list of things to accomplish in the garden, beginning with a few minutes to apply the corn gluten. I attached the hose to another faucet and began the process. I soon realized the delivery problem from the evening before had not magically fixed itself. The product had apparently congealed in the bottom of the bottle while sitting on the shelf. Lou dumped it out into another container and vigorously stirred it until it appeared normal. He put it back in the hose end sprayer, and problem solved. We thought.

Four hours later I was in a nasty mood, and Lou and I were snarling at each other. I was still trying to apply the corn gluten, which refused to stay in solution, no matter how much shaking or stirring. I had abandoned the sprayer that came with it and used my own sprayer, which also clogged quickly but at least I could clean it. Lou kept telling me to just dump the stuff out. Finally, I gave up. 

There was still a lot of it in the bucket that Lou had used for stirring. I picked the container up with the intent to toss its contents on a group of weeds out front. I was walking across the patio when the handle to the bucket broke, and the whole mess of orange gritty corn gluten solution splashed over me and into my shoes, then spread across the patio.

After the fact, I checked reviews online about my particular corn gluten product. Every single review mentioned a problem with the delivery system. I read the same frustration I had experienced. How many folks who try this product will go back to artificial chemicals? Next time I will pay the shipping costs for my previous organic weed and feed, if I can't find a good local alternative. 

Later, I sat on the arbor swing as I sipped a cup of coffee and listened to the birds. I felt the stress leaving my body. It was, in fact, a gorgeous day.