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.

Diseases : Pythium and Phytophtora Root Rot

Rot Rot, Pythium or Phytophthora occurs when soil moisture levels are excessively high and fungal spores present in the soil, come in contact with the susceptible plant. The base of stems discolor and shrink, and leaves further up the stalk wilt and die. Leaves near base are affected first. The roots will turn black and rot or break. This fungi can be introduced by using unsterilized soil mix or contaminated water.

Prevention and ControlRemove affected plants and their roots, and discard surrounding soil. Replace with plants that are not susceptible, and only use fresh, sterilized soil mix. Hold back on fertilizing too. Try not to over water plants and make sure that soil is well drained prior to planting. This fungus is not treatable by chemicals.

Rhizoctonia Root and Stem Rot symptoms look similar to Pythium Root Rot, but the Rhizoctonia fungus seems to thrive in well drained soils.

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 leafminer. Seek a professional recommendation and follow all label procedures to a tee. *GDD numbers should be available from your local Cooperative Extension office.

Fungi : Downy Mildew

Downy Mildew, a fluffy white fungal growth that develops on the underside of leaves, is most common during cool, humid conditions. Foliage often discolors and is stunted.

Prevention and Control: Use disease free plants and space far enough apart so that air circulation is good. Remove and discard infected leaves or even entire plants. Use a recommended fungicide and always follow the directions on the label.