The subtropical avocado tree, which comes in Guatemalan, West Indian and Mexican varieties, grows 15 to 40 feet high in only the warmest states. These summer and fall bloomers produce the popular avocado fruit.
All avocado trees require good drainage. They not do well in areas that are prone to flooding, and over watering can cause root rot. During rainy periods, no additional water is required.
Young avocado trees require extra water to become established. Generally two additional waterings a week during the first two to three months after planting meets the young tree's needs.
Established avocado trees need regular watering to support the canopy and roots. Watering mature trees is critical during bloom time through fruit set.
Except for the four coldest months, mature avocados with up to a 20-foot canopy need 600 to 1100 gallons of water per month. During extremely dry periods, they require up to 1200 gallons of water. Young trees with up to a 4-foot canopy need 20 to 40 gallons of water per month and can take up to 50 gallons of water during the hottest months.
Current practice calls for planting avocados on a heavily-mulched mound. Water is applied to the mound according to climate conditions, season and the avocado tree's general requirements.