Petunia
Petunia x hybrida
Prolific bloomers ideal for containers and borders. Their sticky leaves trap some small insect pests, making them useful companions.
Overview
Companion Planting
Basil
TomatoToxicity
Petunias are listed as non-toxic to dogs, cats, and humans by the ASPCA and most poison-control references.
Planting Tips
1 cm of water per m² equals 10 liters. Use the Watering Calculator for exact amounts.
Care Tip: Deadhead spent blooms regularly and cut back leggy stems by half in midsummer to encourage bushier growth and continuous flowering.
Common Pests
Aphids
Symptoms: Curled, yellowing leaves and sticky honeydew residue on foliage; sooty mold may develop.
Treatment: Spray with insecticidal soap or neem oil; strong water jets can dislodge light infestations.
Prevention: Encourage natural predators like ladybugs and avoid excessive nitrogen fertilization.
Tobacco Budworm (Helicoverpa virescens)
Symptoms: Holes chewed in flower buds and petals; buds may fail to open or open with ragged edges.
Treatment: Hand-pick caterpillars at dusk; apply Bacillus thuringiensis (Bt) spray to young larvae.
Prevention: Inspect buds regularly in the evening and remove eggs; rotate planting locations annually.
Spider Mites
Symptoms: Fine stippling or bronzing on leaves, tiny webbing on undersides of foliage, leaf drop in severe cases.
Treatment: Spray undersides of leaves with a strong water stream or apply miticidal soap or neem oil.
Prevention: Maintain adequate humidity around plants and avoid drought stress; remove heavily infested leaves.
Common Diseases
Botrytis Blight (Gray Mold)
Symptoms: Gray, fuzzy mold on flowers and stems; water-soaked spots that turn brown and mushy.
Treatment: Remove and discard infected plant parts; apply a fungicide containing chlorothalonil or copper if severe.
Prevention: Space plants for good air circulation, water at the base rather than overhead, and promptly remove spent blooms.
Powdery Mildew
Symptoms: White, powdery coating on leaves and stems; affected leaves may yellow, curl, and drop.
Treatment: Apply neem oil or a sulfur-based fungicide; remove heavily infected foliage.
Prevention: Ensure full sun exposure, good air circulation, and avoid overhead watering in humid conditions.
Root Rot (Phytophthora / Pythium)
Symptoms: Wilting despite moist soil, yellowing lower leaves, dark mushy roots, and stunted growth.
Treatment: Remove affected plants; drench remaining plants with a phosphonate-based fungicide if caught early.
Prevention: Use well-drained soil or containers with drainage holes; avoid overwatering and waterlogged conditions.