The Salt River Valley in Maricopa County, Arizona is suitable for orange cultivation. Dwarf oranges can grow well either outdoors or in containers. When planting your oranges outdoors, dig a hole three to five times the width of the pot and allow the top of the root ball to extend about an inch above the surrounding soil. Don't add fertilizers when planting oranges in the Salt River Valley.
Marrs oranges are a semi-dwarf tree that can be kept small by pot growing or by pruning to limit size. Marrs oranges grow well in Maricopa County, but will also grow in surrounding counties and areas of similar climate. Marrs oranges have a moderate number of seeds, with each fruit averaging between 7 and 10 seeds. Marrs is a variety of sweet orange. Although Marrs oranges reach maturity early in the season, they generally don't ripen until November. Other sweet oranges that do well in the Salt River Valley include Diller, Hamlin, Trovita and Pineapple.
Valencias grafted to dwarf root stock are dwarf trees. Valencias grown as dwarfs yield between 50 to 60 percent less than full sized trees.Valencias are deep orange and very popular for making orange juice because of their high sugar content. Valencia reaches maturity around March. Aside from their sweetness, Valencia oranges are also popular because they have relatively few seeds. Valencias average between 0 and 6 seeds per fruit. Two varieties that do well in the Salt River Valley of Arizona are Campbell and Oneida. If you want seedless Valencias, you might consider Delta and Midknight.
Blood oranges can grow as dwarfs if grafted to a dwarf root stock. The segments of blood oranges grown in cooler climates develop a deep red color. However, they may not develop deep red internal colors when grown in Arizona because of the Arizona heat. The Salustiana variety of blood orange produces the most consistent blood red color when grown in the Salt River Valley. The Ruby, Moro, Tarroco and Sanguinelli also sometimes develop good red color, depending on the temperatures that year. Grown in cooler parts of Arizona, these can develop good color during cooler years.