Prevention and Control: If possible, select resistant varieties. Keep nitrogen-heavy fertilizers to a minimum as well as over-irrigating as they encourage lush growth. Practice crop rotation and prune out or better yet remove infected plants.

Pest : Tomato Hornworm

These large green caterpillars have diagonal white stripes along their body with a prominent horn on their tail end. They are the larvae of the brown sphinx moth. Look for these caterpillars clinging to the undersides of leaves and stems. Even if you don't see them, you may know they were there because of the black excrement they left behind as well as the leaves they have chewed through. They are also fond of fruit.

Prevention and Control: Rotate tomato location each year and deeply till soil to expose pupae. Floating row covers in June or July help to prevent active moths from laying eggs. Handpick and destroy caterpillars when found. Consult your local garden center professional or county Cooperative Extension office for legal pesticide/chemical recommendations.

Pest : Spider Mites

Spider mites are small, 8 legged, spider-like creatures which thrive in hot, dry conditions (like heated houses). Spider mites feed with piercing mouth parts, which cause plants to appear yellow and stippled. Leaf drop and plant death can occur with heavy infestations. Spider mites can multiply quickly, as a female can lay up to 200 eggs in a life span of 30 days. They also produce a web which can cover infested leaves and flowers.

Prevention and Control: Keep weeds down and remove infested plants. Dry air seems to worsen the problem, so make sure plants are regularly watered, especially those preferring high humidity such as tropicals, citrus, or tomatoes. Always check new plants prior to bringing them home from the garden center or nursery. Take advantage of natural enemies such as ladybug larvae. If a miticide is recommended by your local garden center professional or county Cooperative Extension office, read and follow all label directions. Concentrate your efforts on the undersides of the leaves as that is where spider mites generally live.

Pest : Whiteflies

Whiteflies are small, winged insects that look like tiny moths, which attack many types of plants. The flying adult stage prefers the underside of leaves to feed and breed. Whiteflies can multiply quickly as a female can lay up to 500 eggs in a life span of 2 months. If a plant is infested with whiteflies, you will see a cloud of fleeing insects when the plant is disturbed. Whiteflies can weaken a plant, eventually leading to plant death if they are not checked. They can transmit many harmful plant viruses. They also produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal growth called sooty mold.

Possible controls: keep weeds down; use screening in windows to keep them out; remove infested plants away from non-infested plants; use a reflective mulch (aluminum foil) under plants (this repels whiteflies); trap with yellow sticky cards, apply labeled pesticides; encourage natural enemies such as parasitic wasps in the garden; and sometimes a good steady shower of water will wash them off the plant.

Pest : Aphids

Aphids are small, soft-bodied, slow-moving insects that suck fluids from plants. Aphids come in many colors, ranging from green to brown to black, and they may have wings. They attack a wide range of plant species causing stunting, deformed leaves and buds. They can transmit harmful plant viruses with their piercing/sucking mouthparts. Aphids, generally, are merely a nuisance, since it takes many of them to cause serious plant damage. However aphids do produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface growth called sooty mold.

Aphids can increase quickly in numbers and each female can produce up to 250 live nymphs in the course of a month without mating. Aphids often appear when the environment changes - spring & fall. They're often massed at the tips of branches feeding on succulent tissue. Aphids are attracted to the color yellow and will often hitchhike on yellow clothing.

Prevention and Control: Keep weeds to an absolute minimum, especially around desirable plants. On edibles, wash off infected area of plant. Lady bugs and lacewings will feed on aphids in the garden. There are various products - organic and inorganic - that can be used to control aphids. Seek the recommendation of a professional and follow all label procedures to a tee.

Pest : Caterpillars

Caterpillars are the immature form of moths and butterflies. They are voracious feeders attacking a wide variety of plants. They can be highly destructive and are characterized as leaf feeders, stem borers, leaf rollers, cutworms and tent-formers.

Prevention and Control: keep weeds down, scout individual plants and remove caterpillars, apply labeled insecticides such as soaps and oils, take advantage of natural enemies such as parasitic wasps in the garden and use Bacillus thuringiensis (biological warfare) for some caterpillar species.

Pest : Flea Beetles

Flea Beetles are about the size of a flea and are black, bronze, or blue-black in color. They get their name from the way they jump when disturbed. Flea beetle populations are usually more severe when conditions are hot and dry. They can pose problems in the garden; they leave small holes in chewed foliage.

Prevention and control: You've heard it a thousand times, but here it is again - clean up the garden to remove places where these insects over winter. A well-watered, moist garden will not be as attractive to an egg laying mother either. Aside from handpicking, spray with a recommended insecticide. Cultivation between rows will help to destroy eggs, too.

Fungi : Leaf Spots

Leaf spots are caused by fungi or bacteria. Brown or black spots and patches may be either ragged or circular, with a water soaked or yellow-edged appearance. Insects, rain, dirty garden tools, or even people can help its spread.

Prevention and Control: Remove infected leaves when the plant is dry. Leaves that collect around the base of the plant should be raked up and disposed of. Avoid overhead irrigation if possible; water should be directed at soil level. For fungal leaf spots, use a recommended fungicide according to label directions.

Fungi : Black Spot

A known rose disease, Black Spot appears on young leaves as irregular black circles, often having a yellow halo. Circles or spore colonies may grow to 1/2 inch in diameter. Leaves will turn yellow and drop off, only to produce more leaves that will follow the same pattern. Roses may not make it through the winter if black spot is severe. The fungus will also affect the size and quality of flowers.

Prevention and Control:Plant resistant varieties for your area. Always water from the ground, never overhead. Practice good sanitation - clean up and destroy debris, especially around plants that have had a problem. When pruning roses, even deadheading, dip pruners in a bleach / water solution after each cut. If a plant seems to have chronic black spot, remove it. A 2-3 inch thick layer of mulch at the base of plant reduces splashing. Do not wait until black spot is a huge problem to control! Start early. Spray with a fungicide labeled for black spot on roses.

Pest : Leaf Miners

Leaf Miner is actually a term that applies to various larvae (of moths, beetles, and flies) that tunnel between upper and lower leaf surfaces, leaving a distinctive, squiggly pattern. A female adult can lay several hundred eggs inside the leaf which hatch and give rise to miners. Leaf miners attack ornamentals and vegetables.

Prevention and Control: Keep weeds down and scout individual plants for tell-tale squiggles. Pick and destroy these leaves and take advantage of natural enemies such as parasitic wasps. Know the Growing Degree Days (GDD)* for your area to target insecticide sprays when most beneficial for controlling the specific leaf miner. Seek a professional recommendation and follow all label procedures to a tee. *GDD numbers should be available from your local Cooperative Extension office.

Diseases : Blight

Blights are cause by fungi or bacteria that kill plant tissue. Symptoms often show up as the rapid spotting or wilting of foliage. There are many different blights, specific to various plants, each requiring a varied method of control.

Pest : Colorado Potato Beetle

Colorado Potato Beetle is 1/3 inch long, has black and yellow striped wing covers, and a distinguishing darker yellow thorax, or ""vest"", with black spots. Grubs, which are about 1/4 the size of the adult, are reddish-brown with small, black spots. Adults and larvae feed on leaves and stems, leaving behind black excrement. Their voracious feeding habits can be devastating.

Problems begin in the spring when adult beetles emerge from the soil to feed and lay hundreds of eggs on the undersides of leaves. There can be up to 3 generations per year.

Prevention and Management: Thick mulch or floating row covers can prevent pests from reaching plants. Marigold, catnip, and tansy seem to deter beetles as well, because of their strong fragrance. Handpicking adults is another option. Insecticides that are labelled to control Colorado Potato Beetle can be used. Follow the label to a tee.