Avocado trees (Persea Americana) are attractive, rapidly growing plants that are acceptable for growing outside in the mild areas of U.S. Department of Agriculture plant hardiness zones 9B through 11. In cooler climates, avocado trees are often grown inside where they create spectacular houseplants. However, because the trees eventually grow to heights of 30 to 40 feet, indoor avocados are often discarded after a couple of decades. Proper watering is vital for avocados grown both indoors and outside, as the dirt should not be either too wet or too dry.
Outdoors
Water an outdoor avocado tree providing enough moisture to completely saturate the root zone. Water with a sprinkler or permit a hose to trickle slowly at the base of the tree.
Examine the soil with your finger before watering again and water only if the cap of the soil feels dry. The frequency of irrigation is based on the temperature. In hot, dry weather, the avocado tree may require irrigation daily.
Spread 2 to 3 inches of mulch such as bark chips or pine needles around the tree in spring and fall. The mulch conserves water and prevents the soil from becoming bone dry. Keep the mulch at least 6 inches away from the trunk.
Water your avocado tree through the winter only if the weather is unusually dry. If the soil is moist, do not irrigate.
Indoors
Expand your avocado in a container with a drainage hole. Without adequate drainage, the plant is susceptible to rot and other ailments.
Water an indoor avocado as often as needed to keep the soil slightly moist, but do not over-water. Soggy soil may result in yellow or curly leaves in addition to moisture-related diseases.
Place the avocado tree in a bathtub or sink when the tips of the leaves appear brown or scorched, as this indicates a accumulation of salt from the potting mix. Water the plant generously, and permit water to run through the drainage hole. Then let the pot drain entirely.