PlantAmerica's Plant Care Sheet
Leaf Spots
These brown or black spots and patches (ragged or circular, with water soaked or yellow-edged appearance) can be caused by a variety of bacteria and fungi. Insects, rain, dirty garden tools, or people can spread bacteria.
Prevention and Control: Remove infected leaves, water plants at the base, and avoid spraying foliage when watering. Use sulfur spray on woody plants in winter.
How-tos:
Fertilizing Houseplants
Houseplants may be fertilized with either water-soluble, quick release fertilizers, temperature controlled slow-release fertilizers, or organic fertilizers such as fish emulsion. Water soluble fertilizers are used every two weeks or per lable instructions. Controlled, slow-release fertilizers are worked into the soil usually only once during the growing season or per label directions. For organic fertilizers, such as fish emulsion, follow label directions.
Pests:
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 may have wings. They attack a wide range of plant species, causing stunting, deformed leaves and buds, and can transmit many harmful plant viruses. Aphids, generally, are merely a nuisance, since it takes many of them to cause serious plant damage. Aphids do produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal 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 and fall) and they often mass at the tips of branches feeding on succulent tissue. Aphids are attracted to the color yellow and often hitchhike on yellow clothing.
Prevention and Control: Keep ant population under control; they tend to cultivate pests that produce the honeydew of which they are fond. Keep weeds down, use screening in windows to keep them out or your home. On edibles, wash infected areas of plants by hand, or introduce lady bugs and lacewings that love aphids. Insecticidal soaps, neem, and dusting leaves and stems with diotomacious earth also help, covering tops and undersides of leaves. Dormant oil sprays may be used on dormant roses. As a last resort, treat severe infestations with pyrethrin, malathion, or acephate according to label.