Malus domestica
 
The fruit has a mild, sweet, and sometimes slightly tart flavor.  It is a popular apple for fresh eating, salads, and cooking.
At maturity, the tree will reach heights of 12-15 feet. 
Soil type needed: Average to loamy soils that are moist with good drainage.  Apple trees do best with a slightly acidic soil pH in the range of 5.0 to 6.8.
Sun Preference: Galas prefer full sun and ample air movement around the tree and through its branches. It is not recommended to place the tree near taller trees or structures that would shade it for a few hours each day.
Pollination: Most any variety will work if the bloom periods overlap adequately.  The crabapple is often suggested due to its long bloom time. The Gala blooms in early-mid spring with a mid-season harvest in October.  For the Gala specifically, Fuji or the Red/Yellow Delicious apple trees are good bloom matches.