Cactus Rot Causes

Overwatering Cacti

• Cactus plants grow in desert conditions where rains are infrequent. To cope with the harsh environment, cacti developed the ability to store water in their fleshy interiors. Cacti require very little water to survive. Too much water stresses the plants and invites fungal and bacterial infections to take over. Plant outdoor cacti away from irrigated lawns and garden beds where you can control the amount of water they receive. Select cacti that grow wild in your area or ask at a garden center for a good variety to suit your specific climate conditions and rainfall.

Soil and Drainage

• Bad soil drainage means a moist environment around cacti and too much moisture quickly leads to rot problems. Avoid planting cacti in heavy, wet clay soil or low-lying areas that collect moisture. Plant cacti in rocky, dry soil and high ground. Spread a 2-inch layer of gravel over the area around the cacti to keep bacteria from forming on the soil surface. Plant potted cacti in a well-draining cacti and succulent mix formulated for good drainage. A homemade mixture of equal parts sand and well-draining potting soil works well. Sterilize the soil by heating it in the oven at 180 F for 30 minutes. Adjust the oven temperature as needed to keep the internal soil temperature at 180 F and below 190 F.

Watering Practices

• Water cacti close to the roots. Many rot-causing fungal and bacterial infections can transfer between unhealthy plants and healthy plants in a drop of water. Splashing water over the cacti garden encourages disease to spread. Water early in the morning when the air is still cool. Discontinue watering in the the winter when cacti go into dormancy. Water indoor potted cacti when the soil at the bottom of the pot dries out. Test the soil moisture by sticking a pencil down to the bottom of the pot, if it is damp at the tip, hold off on watering.

Planting Depth and Feeding

• Keep the stem above the soil line. Cacti have fleshy stems prone to rot and disease. When planting a cacti, put it in the ground just deep enough so that the roots are secure but so that none of the stem is below the soil line. Plant cacti in dry soil and wait at least one to two weeks before watering. Avoid overfeeding cacti, it only stresses the plant and encourages rot-causing infestations. Feed cactus plants once a year, twice at most.