Is it a bug or is it a fungus?

Telling the difference between insects and fungus or disease problems is not a simple task! Remember when giant whitefly first showed up? Many thought it was fungus because of the fuzzy filaments hanging from the undersides of the leaves and reacted by spraying fungicides, which weren't any help at all.

Actually, insecticides didn't help much either--as we soon found out--due to the many generations present (some of which were resistant) at the same time. Since the mouthparts of giant whiteflies are long and tubular, a good blast with the hose is actually one of the best methods of getting rid of them!

Many other bugs also leave damage that looks much like fungus. In some cases, such as aphids (honeydew produced by the aphids promotes the growth of sooty mold), they actually attract mold or fungus. Using a fungicide may get rid of a symptom but leave the original problem.

Another example: small holes in the leaves of plum, nectarine, almond, and apricot trees are actually symptoms of "shot hole" fungus, but if you see tiny holes in your eggplant's leaves--you probably have flea beetles!

As you can see, diagnosis is not always easy! Bring a sample in and we'll try to help diagnose problems and find the best cure for your problem.

As always, the first and best line of defense is prevention. Keep plants healthy--avoid injuries (such as hitting trees with lawnmowers, etc.). Choose varieties that do well in your area and are naturally resistant. We can help you choose resistant plants that will thrive for you.

Disease occurs when the conditions exist to allow it. It is an interaction between the pathogen (causative agent), environmental conditions, and host (plant). All these must be present. That's why prevention is so important. Consult our nursery professionals for help.

Garden Terms:

Pathogens: Microorganisms that cause disease.

Host: Plant that sustains the pathogen.

Spraying Tips

Whether you use our organic or conventional sprays, you can get the most out of your spraying by following these tips:

1. Make sure the spray is getting UNDERNEATH the leaves. Mites, whiteflies, and many others spend most or all of their time there, so spraying only on the top surfaces will not control them.
2. Don't spray a bone-dry plant, and don't spray in the middle of a very hot day. Early morning is a good time to spray because it's usually cooler and less windy, and the insects are less active--so more spray hits the pests.
3. Follow all label directions. Don't use a more concentrated spray than the label recommends--you can easily burn your plants, and usually it is no more effective on pests. If you have any questions, don't hesitate to consult our nursery professionals.

Don't be discouraged from growing fruit just because the space in your garden is limited. Even if there is insufficient room for apples or pears, many container gardens can support currants or one of the unusual berries. These take up little space and are seldom found in the grocery store. And don't forget the ever-popular strawberries!

Currants - they grow well in cool temperate climates and make a good alternative for the patio gardener who lives in a colder climate. Black, red, and white currants can all be grown in containers against a wall, and can be trained as cordons or espaliers.

Hybrid Berries - some of the hybrid berries, thornless blackberries, tayberries, and loganberries can be grown in a container against a wall. They do need a framework of wire but they are easy to train.

Strawberries - the favorite fruit for the patio gardener. Strawberries are especially attractive grown in special planters or tubs, with white flowers in late spring and delicious red fruits ripening in summer. They can also be grown in growing bags, planted in late summer to bear fruit the following year.

It is possible to retain strawberry plants in growing bags for two years but it is probably best if they are replanted annually. Since they are a greedy crop, make sure you add slow-release fertilizer when you plant them.

With the focus on roses this time of year, an important beneficial insect to get to know is the ladybug or, more properly, "lady beetle." We'll talk about two here: the vedalia beetle (Rodolia cardinalis) and the convergent lady beetle (Hippodamia convergens).

Vedalia lady beetles eat aphids, scales, and other soft bodied insects. Most people are familiar with the adult, which is round, red with black spots, and about 1/4 inch long. This beetle was brought to the US from Australia in 1888 and saved the citrus industry in California by controlling cottony cushion scale. It is well-established in Florida now, as well. In addition to scale, the adult and larva have an appetite for aphids - a common rose pest. The larvae look like little dragons or alligators. Their long narrow bodies - about 1/3 inch long - are reddish-gray.

Convergent lady beetles are a native species and far more common. These are the ones most Americans think of when the word "ladybug" is used. They, and their larvae, also have an appetite for aphids and other pests. The larvae are darker with brighter markings

These ladies are easy to spot - look near the new growth at the tips of plants and on young buds. Watch for them in your own garden. Don't spray them; they are our best helpers!

Get to know your beneficial insects. They can be very useful in keeping the pests away and reducing the use of chemicals. And remember - when you do need to use chemicals in your garden, read the instructions carefully and consult with one of our nursery professionals, who can advise you on the best one to use for your particular problem.