Powdery Mildew
This fungus disease occurs all over the North America and infects a wide variety of plants, including beans, cucurbits, lettuce, and peas. A powdery white growth covers the upper surface of leaves, which eventually turn yellow and dry. Older ... [... more]
National Gardening Association |
Late Blight
Late blight strikes tomatoes and potatoes all over North America at any stage of growth. Irregular gray spots form on leaves. White mold grows on the undersides of these spots. Infected leaves turn brown and dry up. Gray, water-soaked spots on ... [... more]
National Gardening Association |
Phytophthora Fruit Rot
This fungal disease affects all cucurbits, especially winter squash and pumpkins. It is most common in humid areas of North America. Fruit in contact with soil are especially susceptible. The infection begins as a watersoaked spot or depression, ... [... more]
National Gardening Association |
Corn Smut
This fungus disease occurs on corn over most of the United States. It can infect any aboveground part of the plant, causing galls that are white and spongy when young, which later become gray-brown and filled with powdery black spores. Spores are ... [... more]
National Gardening Association |
Early Blight
This fungus disease attacks tomatoes and potatoes over most of North America. Plants under stress or with a heavy load of fruit are most susceptible. Dark brown spots with concentric rings in them form on older leaves first. Infected leaves turn ... [... more]
National Gardening Association |
Downy Mildew
Various types of downy mildew fungi cause disease in a number of crops across North America. Irregular brown or yellow spots develop on the upper leaf surface; the lower leaf surface beneath these spots is covered with a hairy white or purple ... [... more]
National Gardening Association |
Snakes
Although popular lore suggests snakes should be feared or exterminated, relatively few are poisonous and they generally avoid humans. Besides, they can be the gardener's friend, as various snakes prey upon rodents and slugs. Seeing snakes in your ... [... more]
National Gardening Association |
White Mold
This fungal disease occurs all over North America and can attack a wide variety of plants such as beans, lettuce, and members of the cabbage family. Symptoms on beans begin as water-soaked spots on blossoms, stems, leaves, and pods that enlarge ... [... more]
National Gardening Association |
Blossom End Rot
Blossom End Rot (BER) is a physiological disorder of tomatoes, peppers, and cucurbits caused by a calcium imbalance within the plant. Fluctuations in soil moisture, excessively wet or dry soil, excessive nitrogen fertilizer, roots damaged by ... [... more]
National Gardening Association |
Septoria Leaf Spot
Tomato plants in many parts of the North America can suffer from this fungal disease, which can appear at any time. Symptoms first appear on oldest, lower leaves. Gray-brown areas have gray centers and a darker border. The dark border lacks the ... [... more]
National Gardening Association |
Viruses
There are many kinds of viruses that can infect a wide variety of plants all over North America, including beans, celery, corn, cucurbits, peas, peppers, spinach, and tomatoes. Symptoms vary with the specific virus, but include mottling, ... [... more]
National Gardening Association |
Potato Scab
This disease, caused by a bacterialike organism, affects potatoes all over North America. Brown, corky areas or pits cover the outside of the tubers. Neutral and alkaline soils encourage the development of scab. Other susceptible crops include ... [... more]
National Gardening Association |
