Spraying Hydrangeas
Spraying is important to the survival of your plants. To handle potential diseases and pests, reference the guidelines below to know what you should spray, and when you should use it.
NOTE: This is part 9 in a series of 10 articles. For a complete background on how to grow hydrangeas, we recommend starting from the beginning.
Before you begin, read and follow all instructions on labels.
General Guidelines
Natural Control
- Serenade® Garden Disease Control for powdery mildew and leaf spot.
At the First Sign of:
- GardenTech® Sevin® Concentrate Bug Killer for aphids, mealy bugs, white flies, thrips, Japanese beetles and more.
By Shrub
Flowering/Ornamental Shrubs
New spring growth:
- Monterey Liquid Copper Fungicide for leaf spot.
New spring growth:
- Monterey Liquid Copper Fungicide for black spot, downy mildew, gray mold, leaf spots, powdery mildew and rust.
Ornamental Shrubs
Green tip through delayed dormant stages:
- Monterey Horticultural Oil for scale insects, certain aphids, gall, whitefly larvae, mealy bugs and adelgids.
Growing season:
- Monterey Horticultural Oil for scale insects, red spider mites, mealy bugs and whitefly larvae.
At first sign of insects:
- Natural Guard® Caterpillar Killer Spray w/BT for bagworms, tent caterpillars and fall webworms.
Euonymus, Lilac
At first sign of insects:
- GardenTech® Sevin® Concentrate Bug Killer for aphids, bagworms, exposed thrips, fall cankerworms, inchworms, leaf miners, leaf rollers, locust, mealy bugs, spider mites, whiteflies, gypsy moth, tent caterpillar and Japanese beetles.
Spring bud break:
- Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for anthracnose.
Nannyberry, Lilac
At first sign of insects:
- GardenTech® Sevin® Concentrate Bug Killer for aphids, armyworms, bagworms, cutworms, exposed thrips, fall cankerworms, fall webworms, fungus gnats, inchworms, Japanese Rotenone beetles, leaf miners, leaf rollers, locusts, mealy bugs, scale crawlers, spring cankerworms, spider mites, whiteflies, psyllids and scale insects.
Privet
Prolonged wet conditions:
- Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for cercospora leaf spot.
Viburnum
Mid-summer:
- Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for powdery mildew.
Hydrangea (foliage only)
Early propagation:
- Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for cercospora, septoria leaf spot and rust.
Lily
Pre-bloom:
- Ferti-lome® Broad Spectrum Landscape & Garden Fungicide for botrytis gray mold (foliar phase) and phytophthora blight.
Hardy Shrub (Thrives with minimal care such as lilac, viburnum, privet, spirea, etc.)
Growing season:- Monterey Horticultural Oil for scale insects, European red spider mites, mealy bugs and whitefly larvae.
