Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN®
Acer x freemanii
Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® (Acer x freemanii) is a tree suited to the Colorado Front Range, rated "Not Recommended" on the 2024 Front Range Tree Recommendation List. It matures to about 40–60 ft tall and 30–50 ft wide, fast-growing, needs medium water, and prefers full sun to partial shade. Develops iron chlorosis in our alkaline soils, leaves yellow with green veins, then decline.
medium water40–60 ft tall and 30–50 ft wide
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At a glance
- Rating
- Not Recommended
- Botanical name
- Acer x freemanii
- Variety / cultivar
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN®
- Type
- Tree
- Mature size
- 40–60 ft tall and 30–50 ft wide
- Mature form
- Oval / upright
- Spacing / clearance
- ~50 ft of clearance
- Hardiness zones
- USDA 4–8
- Growth rate
- Fast
- Lifespan
- Medium
- Fall color
- Red, orange
- Water needs
- medium water
- Sun
- Best in full sun; tolerates partial shade.
- Colorado native
- No
- Foliage
- Deciduous
- Soil
- clay, loam, sandy
- Soil pH
- 6.0–8.2
- Hail tolerance
- moderate
- Wind tolerance
- moderate
- Salt tolerance
- moderate
- Pollinator value
- high
- Tolerates
- Rain gardens
Site factors to consider
- Critical: Soil ChemistryOur alkaline clay locks up iron for this one, so leaves often yellow between green veins and growth stalls unless you treat it.
- Watch: SuckersIt throws up shoots from the roots and base, so plan on cutting suckers to keep it from turning into a thicket.
- Watch: Re-seedsIt sets seed freely and plants itself around the yard, so pull the volunteer seedlings unless you want more of them.
Wildlife & ecology
- Pollinator value
- high
- Deer
- Not deer-resistant
Common problems on the Front Range
- Aphids and honeydew
- Verticillium wilt on some species
- Leaf scorch in hot, dry, windy sites
These are general tendencies for this group of plants on the Front Range, not a diagnosis. Many are stress-driven and preventable with good siting and watering. For a specific plant or an active problem, consult a certified arborist or your local CSU Extension office.
Frequently asked questions
- Is Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® good for the Colorado Front Range?
- Yes, Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® is a well-suited tree for Colorado's Front Range, rated "Not Recommended" on the 2024 Front Range Tree Recommendation List.
- Why is Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® not recommended on the Front Range?
- The main catches here: Our alkaline clay locks up iron for this one, so leaves often yellow between green veins and growth stalls unless you treat it.
- How big does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® get?
- It matures to about 40–60 ft tall and 30–50 ft wide.
- How much room does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® need?
- Give Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® about 50 ft of clearance from buildings, fences, and other trees so the mature canopy isn't crowded.
- What shape does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® grow into?
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® typically grows into an upright-oval crown, taller than it is wide. This is the species' usual mature form, named cultivars (columnar, weeping, or compact selections) can differ, so check the specific cultivar.
- Is Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® hardy on the Front Range?
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® is hardy in USDA 4–8. The Colorado Front Range spans roughly USDA 4b–6a, so it is well within range.
- How much water does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® need?
- It needs medium water once established.
- How fast does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® grow?
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® is a fast-growing tree. Growth rate depends on water and site conditions on the Front Range.
- How long does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® live?
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® has a moderate lifespan for a Front Range tree. Actual lifespan varies with site, water, and care.
- What color does Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® turn in fall?
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® turns red and orange in autumn. Fall color intensity varies with the season and site on the Front Range.
- Is Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® native to Colorado?
- No. It is not a Colorado native, but it grows well on the Front Range.
- Is Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® deer-resistant?
- No. Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® is not considered deer-resistant and may need protection where deer browse.
- Is Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® prone to pests or disease on the Front Range?
- Freeman - 'Armstrong', AUTUMN BLAZE®, AUTUMN FANTASY®, SIENNA GLENN® can be affected by aphids and honeydew and other issues common to this group on the Front Range. These are general tendencies, not a diagnosis, many are stress-driven and preventable with good siting and watering. For a specific plant or an active problem, consult a certified arborist or CSU Extension.
