Hardiness zones:
Sunset 9, 12-24
USDA 9 (needs cold protection when young) - 11
Landscape Use: Large to massive evergreen to semi-evergreen shade tree, parks, commercial, large areas and mesic design themes. Not for small residential sites.
Form & Character: Briefly deciduous to evergreen tree (depending on winter cold in Phoenix), upright and rounded, potentially massive and stout
Growth Habit: Vigorous to 80' in height with a 60' spread.
Foliage/texture: Larger, pinnately compound green leaves, mostly 7, sometimes 9, leaflets per leaf. Leaflets are ovate to lanceolate with serrate, sometimes revolute margins, trunk and branches smooth when young becoming slightly rough with age, medium to medium coarse texture
Flowers & fruits: Dioecious, flowers inconspicuous born on separate trees in mid winter just before or at leaf emergence, fruit a winged achene, inconspicuous
Seasonal color: Marginal and inconsistent (from year to year depending on the weather) golden yellow early winter color.
Temperature: Freezing temperatures will defoliate most trees and can kill young twigs, injured trees recover quickly
Light: Full sun
Soil: Tolerant
Watering: Apply regular water throughout the year
Pruning: Elevate canopy base, not as susceptible to trunk scald like other Phoenix ash trees mainly due to greater heat tolerance and a wider canopy spread
Propagation: Cutting or grafting
Disease and pests: None, appears resistant to ash decline
Additional comments: Lateral buttress roots of mature specimens of Shamel ash can heave concrete. Large canopies can shade out Bermuda turf grass, Ergo, use as a lawn tree and/or around concrete walks and drives with discretion because of heavy surface roots and dense canopy shade. Note that the cultivar 'Majestic' is popular.