Pistachio trees (Pistacia vera l.) grow best in climates with hot, dry summers followed by cool, but not cold, winters. Extremely drought-resistant, they will not tolerate high humidity, making them ideal for drier regions of California and the Southwest. Grow pistachio seedlings in containers, but be prepared to transplant them into the landscape by the time they are three to five years old, or their roots will coil and become pot-bound. The California Rare Fruit Growers Association recommends Peters and Kerman pistachio cultivars for planting in the U.S.
Wash out a large container with hot, soapy water, rinse and allow it to air-dry. Check the drainage holes in the bottom to be sure they are open and functioning. Put a 2-inch layer of river rock or gravel in the bottom.
Mix equal parts peat, sand and organic garden soil and fill the container two-thirds full with the mixture. Moisten with enough water so that it drains from the bottom of the container.
Place the bare-root pistachio seedling in the centre of the container and fill in with soil mix. Take care that the centre root hangs straight down. Press the soil around the roots with your fingers to close air spaces that can dry them out. Make sure the graft union on the trunk (a small scar where pistachio is grafted to rootstock) is 2 inches above the soil line.
Water the seedling until water drains freely from the bottom of the container. Set the potted pistachio in full sun, outdoors on a patio or lanai. Continue watering once a week during the growing season, backing off to once every two or three weeks in winter. Bring the pistachio indoors if frost is forecast.
Fertilise after the first year, in spring, with a 10-10-10 fertiliser. Follow instructions on the package for the size and age of the tree to get the right proportions. Do not fertilise after June or the burst of new foliage will delay the normal dormant stage of the tree.
Re-pot pistachios in a larger container each year, to give roots sufficient room. Container soil loses its nutrients more quickly because of its small area.
Be prepared to transplant into the landscape after three to five years. Pistachios develop a long tap root and they need deep, well-drained soil to survive.