Japanese Lilac
Syringa reticulata
Japanese Lilac (Syringa reticulata) is a tree suited to the Colorado Front Range, rated "Recommended" on the 2024 Front Range Tree Recommendation List. It matures to about 15–25 ft tall and 15–20 ft wide, needs low to medium water, and prefers full sun.
low to medium water15–25 ft tall and 15–20 ft wideXeric / water-wiseDeer-resistant
Photos
- Photo 1: "Syringa reticulata at Winterthur Estate" by TheKohser - Gregory Kohs is licensed under CC BY-SA 3.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/3.0/.
- Photo 2: (c) Jeff D Hansen, some rights reserved (CC BY)
- Photo 3: (c) Loïc Mathieu, some rights reserved (CC BY)
- Photo 4: (c) Loïc Mathieu, some rights reserved (CC BY)
- Photo 5: "暴馬丁香 Syringa reticulata v amurensis [維也納大學植物園 Vienna University Botanical Garden]" by 阿橋花譜 KHQ Flower Guide is licensed under CC BY-SA 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/2.0/.
- Photo 6: Herman, D. E., et al. (1996). North Dakota tree handbook.
At a glance
Will it survive here?
- Hardiness zones
- USDA 3–7
- Water needs
- low to medium water
- Sun
- Best in full sun.
- Soil
- clay, loam, sandy
- Soil pH
- 6.0–8.2
- Hail tolerance
- moderate
- Wind tolerance
- moderate
- Salt tolerance
- moderate
- Tolerates
- Hellstrips / parking strips
How big, what shape?
- Mature size
- 15–25 ft tall and 15–20 ft wide
- Mature form
- Oval / upright
- Spacing / clearance
- ~20 ft of clearance
- Growth rate
- Moderate
- Lifespan
- Medium
What it looks like, and when
- Bloom time
- late spring, early summer
- Bloom color
- cream, white
- Foliage
- Deciduous
Who else benefits
- Pollinator value
- moderate
- Deer
- Generally deer-resistant
- Colorado native
- No
Common problems on the Front Range
- Lilac/ash borer
- Powdery mildew (cosmetic, late season)
- Oystershell scale
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.
Planting & establishment
Water deeply every 7–10 days through the first 2 summers. Winter water 1–2×/month October–March when soil is dry and unfrozen, winter desiccation is a top killer of newly-planted trees. Year 3: taper to 2×/month in summer, then rely on natural precipitation.
Frequently asked questions
- Is Japanese Lilac good for the Colorado Front Range?
- Yes, Japanese Lilac is a well-suited tree for Colorado's Front Range, rated "Recommended" on the 2024 Front Range Tree Recommendation List.
- How big does Japanese Lilac get?
- It matures to about 15–25 ft tall and 15–20 ft wide.
- How much room does Japanese Lilac need?
- Give Japanese Lilac about 20 ft of clearance from buildings, fences, and other trees so the mature canopy isn't crowded.
- What shape does Japanese Lilac grow into?
- Japanese Lilac 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 Japanese Lilac hardy on the Front Range?
- Japanese Lilac is hardy in USDA 3–7. The Colorado Front Range spans roughly USDA 4b–6a, so it is well within range.
- How much water does Japanese Lilac need?
- It needs low to medium water once established.
- How fast does Japanese Lilac grow?
- Japanese Lilac is a moderate-growing tree. Growth rate depends on water and site conditions on the Front Range.
- How long does Japanese Lilac live?
- Japanese Lilac has a moderate lifespan for a Front Range tree. Actual lifespan varies with site, water, and care.
- Is Japanese Lilac native to Colorado?
- No. It is not a Colorado native, but it grows well on the Front Range.
- Is Japanese Lilac deer-resistant?
- Japanese Lilac is generally considered deer-resistant, though no plant is deer-proof when browse pressure is high.
- Is Japanese Lilac prone to pests or disease on the Front Range?
- Japanese Lilac can be affected by lilac/ash borer 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.
