How to Get Rid of Root Rot in an Avocado Tree

Root rot is a common problem in avocado trees. To keep your avocado healthy, you must follow proper watering techniques, plant your avocado correctly, and give it healthy soil conditions. Attack root rot to increase avocado tree health and the production of fruit on your avocado.

You can tell avocado root rot by looking at the roots of the plant. If there are only large plant root shoots and no smaller ones, your plant likely has root rot. Above-ground symptoms of root rot in avocados include pale leaves with brown tips and rotten spots on the stem of the avocado plant. It may also exhibit symptoms like small fruit, leaf loss or total avocado plant death.

To properly plant avocado trees to avoid root rot, space them at least three feet apart to keep infected plants from spreading. Plant them in well-drained soil with lots of rocks, gravel, or other material to help water move through the soil. Water them frequently in the hot summer, every one to three days, and sparsely in the winter, about every week. Check soil to a depth of 8 inches; if it is wet, then the avocado does not need to be watered. If the soil is dry and will not clump, watering is needed.

Use root-rot resistant varieties of avocado plant, and use only sterile soil and planting containers. To sterilize soil, you can bake it until the soil has been at 180 degrees for 20-30 minutes. Do not bake it hotter than 180 degrees. Wear protective gloves. Be sure to take care with the hot sand, since it will not look hot and it will not cool quickly. Allow time for the sand to cool before handling it, and allow the sand to cool completely before using it or you will burn and kill your avocado plant.

According to the University of California Integrated Pest Management guide to avocados, an application of gypsum on the soil surface near the avocado can help dampen root rot diseases. To avoid root rot, start with a disease-free plant that is cultivated to avoid root rot. Common varieties of avocado plant which are resistant but not immune to root rot include Duke and Martin varieties of plant.

If your avocado plant is losing leaves, you may not have root rot. Wait a bit and see if it starts growing again; a few varieties of avocado, though evergreen, lose their leaves before undergoing a growth spurt.

References:

University of California Integrated Pest Management
Rodale's Guide to Organic Gardening by Fern Marshall Bradley, Barbara W. Ellis and Ellen Phillips; 2009
AgFacts: Avocado Diseases