Plant Health Profile
Privet
Ligustrum spp.
Privet is a dense, fast-growing shrub commonly used for hedges, screens, and foundation plantings. In Colorado it is generally tough, but drought stress, dense growth, and poor airflow can allow sap-feeding insects, mites, and foliar diseases to develop—especially on tightly clipped hedges. Shrub / hedge habit Flowers (late spring–summer)
Seasonal Pest & Disease Calendar
- Curled or distorted new growth
- Sticky honeydew; ants often present
- Strong water spray removes aphids effectively
- Usually cosmetic unless distortion becomes severe
- Small bumps on stems/branches
- Yellowing foliage, reduced vigor, possible dieback in heavy cases
- Prune out heavily infested branches
- Best treatment timing is crawler stage (often late May–early June)
- Dormant horticultural oil can help where scale is a known issue
- Fine yellow stippling on leaves
- Dull or bronzed appearance
- Light webbing in hot weather
- Hose undersides of leaves during heat
- Reduce drought stress
- Miticides only if damage is spreading
- White or gray powdery coating
- Most noticeable mid–late summer
- Improve airflow and sun exposure
- Avoid excess nitrogen
- Fungicides optional and usually cosmetic
- Brown or black leaf spots
- Premature leaf drop late season
- Rake and remove fallen leaves
- Avoid overhead watering
- Fungicides rarely needed for homeowners
- Dead branch tips in spring; delayed or uneven leaf-out
- Worse on exposed windy sites and dry winters
- Winter watering during warm, dry spells
- Mulch 2–3 inches deep (keep off stems)
- Spring prune back to healthy wood
- Prune out winter dieback and thin for airflow
- Inspect stems for scale bumps
- Monitor new growth for aphids
- Treat aphids only if distortion increases
- Scale crawlers (best time to treat scale)
- Begin spider mite scouting as heat ramps up
- Watch for mites, powdery mildew, and leaf spot
- Treat mites early if stippling spreads
- Fungicides only if appearance matters
- Remove fallen leaves
- Deep watering before soil freeze
- Winter watering during warm, dry stretches
- No pesticide treatments needed
- Heavy scale causing decline/dieback
- Repeated severe mite bronzing/leaf drop
- Major thinning/loss of vigor year over year
- Light aphids
- Mild powdery mildew late summer
- Minor late-season leaf spotting
| Problem | Type | Active Season |
|---|---|---|
| Aphids Scale insects | Insect Insect | Spring–Early Summer Spring–Summer |
| Spider mites Powdery mildew Leaf spot / blight Winter dieback / winter burn | Mite Fungus Fungus Environmental | (crawlers late spring) Summer (hot/dry) Summer–Fall Summer–Fall Winter–Early Spring |
| Pest & Disease Guide | (Homeowner-Friendly) | |
| 1. Aphids | ||
| Symptoms: | ||
| Treatment: | ||
| 2. Scale Insects | ||
| Symptoms: | ||
| Treatment: | ||
| 3. Spider Mites | ||
| Symptoms: | ||
| Treatment: | ||
| 4. Powdery Mildew | ||
| Symptoms: | ||
| Treatment: | ||
| 5. Leaf Spot / Foliar Blight | ||
| Symptoms: | ||
| Treatment: | ||
| 6. Winter Dieback / Winter | Burn | |
| Symptoms: | ||
| Treatment: | ||
| Treatment Timing Calendar | – Privet (Colorado | Front Range) |
| Icons: Scout | Prune | | Water | Treat | | Sanitation |
| March–Early April ( ) | ||
| Late April–May ( ) | ||
| Late May–June ( ) | ||
| July–August ( ) | ||
| September–October ( | ) | |
| Winter ( ) | ||
| When to Worry vs. | When It’s Cosmetic | |
| When to Worry (Action | Needed) | |
| Mostly Cosmetic (Monitor | Only) |
Diagnostic Imagery
Scale Insects
Spider Mites
Powdery Mildew
Leaf Spot / Foliar Blight
Other plant health profiles
Related services
Great Western Tree Care
Shrub decline is usually a site problem
A Great Western technician can confirm the diagnosis on site before anything is treated — timing matters more than product choice.