Healthy & Beautiful Gardens – Organic disease and pest control

Hello fellow gardeners! I thought this would be a good time to discuss problems we might incur in the garden, either now or soon. After putting in all the hard work that we do, we certainly don’t like to watch it all disappear due to disease or pests, and since I’m against toxins in the environment – I use organics when necessary – I will tell you about a few here today.

First and most importantly is to know that a healthy plant is your best defense. That means correct watering and healthy soil. The plants that usually get attacked by either fungus or pests are usually stressed due to heat, lack of water, too much water, not enough sun, etc. So always address those issues first.

There are many types of diseases that affect various plants and I can’t address them all here now, fungus is a big issue and there are many organic methods to deal with those. Roses are a big one for fungal diseases, from rust, powdery mildew to black spot, these diseases respond to several organic treatments. I use a mixture of baking soda, ½ c. to a gallon of water and a tablespoon of “Neem oil”, you can also add a tablespoon of a liquid soap such as Dr. Bronners, or a mild dish soap, mix well and spray.

Make sure to cover all leaves on plants. If you “overhead water” with sprinklers, which I don’t recommend, this fungicide will wash off, so you might need to hand water with hose for a week, otherwise convert to drip irrigation. This mixture will also help kill off many pests and their eggs as a bonus.

When it gets really hot out plants get stressed, especially those in terra cotta pots, and you may see them fading, shriveling up, and if you look closely you may see very fine webbing on the bottom sides of your leaves – this is the spider mite. The fastest way to get rid of them is with a hard jet of water, as well as watering the plant more of course, also spraying with a Neem oil or liquid soap in water mixture. Be vigilant!

If you’re dealing with caterpillars my recommendation is something called “Bt” or Bacillus thuringiensis – just ask for Bt at the garden center. It is basically beneficial organisms that caterpillars eat that disrupt their digestive systems and cause them to die. I also try to hand pick as many off as I can, it really helps believe it or not, and if you’re growing tomatoes you know how much damage can be done in just one night by them.

Slugs and snails are an easy one with several ways to get rid of them. Place boards out at night where they have been seen when they are active. They will hide under them. Pick the boards up in the morning and throw them in the trash. Bury a saucer full of flat beer in the garden where they frequent – both slugs and snails will be attracted to it and drown.

Diatomaceous earth – one of my personal favorites – sprinkle around in the area they frequent, this is also good for those annoying “pillbugs” and it literally cuts them up as they crawl through it. You can buy a box of this at most nurseries or pool supply centers.

One of my most annoying pests, indoors and out, has been a little fly called the “fungus gnat.” They usually come from the nursery and are already in the potting soil. They can destroy a greenhouse in no


I have used yellow sticky traps to good advantage, along with setting out bowls of water to which I add a drop or two of liquid soap – they are attracted to the water, but then can’t fly away and drown.

In addition to these after the fact control methods, I highly recommend encouraging the many beneficial insects out there to live in your garden by providing sources of nectar for them.

Ladybugs, praying mantis, and green lacewings are three of the top in my opinion. Many of these insects are available to purchase if you don’t see them in your garden already and need them. If you refrain from using toxic chemicals, you will usually see the beneficial insects coming in to feast. There are many plants that encourage them to stay in your garden as well – dill is a great one to grow for


Have fun in your garden and as always I’m available for consultations and design work.

Linda McDonald-Cash

Landscape Designer

(951) 764-4762

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