Vitis vinifera 'Thompson Seedless'
Light: Full sun for best fruiting; in Phoenix, protection from intense western afternoon sun can reduce fruit sunburn.
Water: Deep, regular irrigation during active growth and fruit development, especially in Phoenix summer heat. Allow the soil surface to dry between waterings without letting the root zone become severely dry. Reduce watering during winter dormancy.
Soil: Deep, well-drained loam preferred; tolerates sandy or clay soils with adequate drainage. Phoenix’s alkaline soils may cause iron deficiency. Mulch the root zone, keeping mulch away from the trunk.
Mature size: 15–30 feet long or more if unpruned; height and spread depend on support and annual pruning.
Bloom: Small flower clusters appear in spring, usually March–April in Phoenix; grapes typically ripen in early to midsummer, depending on weather and care.
Evergreen / deciduous: Deciduous.
Growth rate: Fast once established.