Diagnosing the Deficiencies and Toxic Elements in your "Sick" Hydroponics Garden

 

Hydroponic gardeners may have a unique way to raise their crops but their plants are still susceptible to many plant diseases commonly found in plants that grow in soil.  Typical diseases that affect hydroponic gardens are fungal or humidity related.  While there are plenty of chemicals available on the market to treat these diseases you will still need to know how to diagnose your sick plants in your hydroponic garden.

 

The most common sicknesses in hydroponic plants are related to the leaf.  Recognizing these common problems when they occur will help you take the right action in treating your sick plants.  Rust is a problem that affects the leaves of a plant and there are over 5,000 varieties of this fungus.  It is identified initially as yellow spots on the leaves.  If not treated the spots will grow larger and turn into reddish brown elevated lesions that contain orange powdery spores.  The treatment is simple though.  Pick off the affected leaves and dispose of them outside of your grow room; do not compost these leaves or you risk infecting other plants.  Sulfur or copper sprays should be used on infected plants weekly and throughout the growing season; avoid spraying during hot weather. 

 

Powdery mildew is another common fungal disease that affects plants in hydroponic gardens.  This disease is identified as blister-like lesions that form on the leaves.  The leaves begin to curl and a white or gray powdery substance appears on the upper parts of the leaves on the infected plant.  This disease predominantly affects new growth on plants.  Watering the diseased plants in the morning so that their leaves have a chance to dry thoroughly can control this fungus.  All diseased plant debris that has fallen off must be removed; do not compost the diseased leaves.  Copper or sulfur sprays can help stop the spread of this fungus when used weekly.  Instead of removing the affected leaves, they can be washed in the morning, which will disrupt the spore producing cycle.

 

Blossom end rot is another common disease but it is not caused by fungus.  It commonly affects tomatoes, peppers and eggplants.  The cause of this disease is insufficient calcium when the plant is budding.  The rot can occur on both green and ripe fruits.  Dark brown spots on the end of the fruit identify this disease.  Keeping plants evenly moist and spraying foliage with kelp or calcium can treat the disease. 

 

The downy mildew fungus appears on the leaves of plants as yellow or white spots.  The spots are visible after heavy dew or rain but tend to disappear after prolonged sunny weather.  As the disease progresses the leaves will turn brown and fall off the plant.  Spore production is increased in temperatures cooler than 65 degrees Fahrenheit or humidity higher than 100 percent.  Insects and dirty garden tools can carry the disease so cleaning your tools frequently can help stop the spread of the disease.  Avoid overhead watering of plants infected with downy mildew.  Treat infected plants with a copper spray every week until harvest time.  

 

Mosaic disease is a viral disease that attacks tomatoes, roses, beans and peppers.  The disease is often misdiagnosed as a nutritional deficiency.  Green or yellow stripes or spots are symptoms of this disease.  Leaves can be wrinkled or curled, growth of the plant is stunted and fruit will have bumps or wart-like areas.  There is no cure for viral diseases so the best control is keeping the virus from entering your garden.  Do not clone these plants, as they will carry the disease.  Treat plants with insecticidal soaps because insects carry the disease.

 

More information on plant diseases and treating them can be found at your local library or on hydroponic gardening websites on the Internet.