Lewis's mock orange
Philadelphus lewisii
Lewis's mock orange (Philadelphus lewisii) is a Colorado-native shrub suited to the Colorado Front Range. It matures to about 6 to 10 ft tall and 6 to 8 ft wide, needs medium water, and prefers full sun to partial shade. Intensely fragrant white blooms, citrus-orange-blossom scent. 'Cheyenne' is the cold-hardy USDA selection.
Colorado nativeOn the CSU listmedium water6 to 10 ft tall and 6 to 8 ft wideLow ignitability: OK 0-30 ft from the house, CSU score 8/10
Photos
- Photo 1: (c) Charles Swift, some rights reserved (CC BY)
- Photo 2: (c) John A Haskins, some rights reserved (CC BY)
- Photo 3: (c) Diane Leeper, some rights reserved (CC BY-SA), uploaded by Diane Leeper
At a glance
Will it survive here?
- Hardiness zones
- USDA 4 to 8
- Water needs
- medium water
- Sun
- Best in full sun; tolerates partial shade.
- Soil
- clay, loam
- Soil pH
- 6.0 to 8.0
- Hail tolerance
- moderate
- Wind tolerance
- moderate
- Salt tolerance
- moderate
How big, what shape?
- Mature size
- 6 to 10 ft tall and 6 to 8 ft wide
- Planting spacing
- ~8 ft apart (6 ft for a hedge/screen)
- Growth rate
- Moderate
What it looks like, and when
- Bloom time
- late spring, early summer
- Bloom color
- white
- Bloom length
- 2 to 3 weeks
- Foliage
- Deciduous
Who else benefits
- Pollinator value
- moderate
- Deer
- Not rated
- Colorado native
- Yes
- Native ecoregion
- foothills
Also worth knowing
- Fire rating
- Low ignitability: OK 0-30 ft from the house, CSU score 8/10
Frequently asked questions
- Is Lewis's mock orange good for the Colorado Front Range?
- Yes, Lewis's mock orange is a well-suited shrub for Colorado's Front Range.
- How big does Lewis's mock orange get?
- It matures to about 6 to 10 ft tall and 6 to 8 ft wide.
- How far apart do I plant Lewis's mock orange?
- Space Lewis's mock orange about 8 ft apart for a full, natural form, or about 6 ft apart for a faster hedge or screen.
- Is Lewis's mock orange hardy on the Front Range?
- Lewis's mock orange is hardy in USDA 4 to 8. The Colorado Front Range spans roughly USDA 4b to 6a, so it is well within range.
- How much water does Lewis's mock orange need?
- It needs medium water once established.
- How fast does Lewis's mock orange grow?
- Lewis's mock orange is a moderate-growing shrub. Growth rate depends on water and site conditions on the Front Range.
- Is Lewis's mock orange native to Colorado?
- Yes. It is a Colorado native.
- Is Lewis's mock orange a good firewise plant near the house?
- Lewis's mock orange is rated 8 of 10 in CSU Extension Fact Sheet 6.305 (2025), where higher means less ignitable, so it can go within 0 to 5 feet of the house as well as out to 30 feet when kept watered and tidy. This is general guidance based on CSU Extension Fact Sheet 6.305 (2025), not a guarantee that any plant won't burn, a well-irrigated, well-maintained plant is the goal. Follow CSU Extension defensible-space guidance and check with your local fire district before planting in the wildland-urban interface.
- How long does Lewis's mock orange bloom?
- Lewis's mock orange blooms for about two to three weeks on the Front Range. Bloom timing shifts a week or two with elevation and spring weather.
