Ilex opaca
American Holly

Mature Height: 40-100'     Longevity: 150 years

2-8 Water Range
Soil moisture tolerated by tree

6-9 Temperature Range
Hardiness Zones in which tree naturally occurs.

DEFENSE     Soil Moisture Key
2: Listed in several sources as present on sandy coastal plain soils. Harlow & Harrar indicates found in North on dry gravelly soil. Not a drought specialist as also found in wet areas.

8: Flood tolerance identified as mid to high. References indicate tree has ability to survive inundation for up to 17% of the growing season.

DEFENSE (from Distribution Maps)
National Audubon Society (NAS) Map: (NORTH) Solid Z6. (SOUTH) Firm Z8 w/ significant intrusion into Z9 in FL.

Peterson Field Guide (PFG) Map: (NORTH) Same as NAS. (SOUTH) Same as NAS, except also presence in Z9 in TX & LA.

3   Sun Strength

8   Shade Strength

DEFENSE
Growth Rate:
Succession:
Soil Range:
Salt Tol.:
Allelopath:
Avg Height:
Max Height:

Click here for Key
2.5 = Slow
0 = Climax Capable
-.1 = 2 Major
+.2 = Moderate
0 = No
-.1 = 50'
0 = 100'

DEFENSE
Shade Tol.:
Succession:
Soil Range:
Salt Tol.:
Allelopath:
Avg Height:
Longevity:

Click here for Key
8 = Very tolerant
+.3 = Climax Capable
-.1 = 2 Major
+.2 = Moderate
0 = No
-.1 = 50'
-.3 = 150 years

TOTAL SCORE (2.5): Slow growing tree that competes better in late seral communities.

TOTAL SCORE (8.0): Short lifespan, limited size and occurrence in limited soil types prevents assignment of top value.

2   Fire Strength

4   Wind Strength

DEFENSE
Base Score: none-low (Big Tree) = 2-3
Literature indicates tree is highly susceptible to fire. Tree will receive lowest big tree rating.
Final Value = 2

DEFENSE
Base Score: ???
Tree typically in understory of forest & does not grow to disproportional heights. Lack of more information prevents assignment of highest rating. Also tough & thick leaves may actually create a significant amount of drag that could lead to high wind load levels.
Final Value = 4