Problems affecting the whole rose plant

Stunted growth, wilting or mass leaf drop usually point to roots, soil, nutrition or a disease that has spread widely.

Where is the problem?

Aphids (family Aphididae — the common pest species on roses is Aphis gossypii) are soft-bodied insects, approximately…

Crown gall is a bacterial disease caused by Agrobacterium tumefaciens, which forms hard, swollen tumour-like galls at…

Drought stress develops when the plant does not receive enough water — through insufficient irrigation, a substrate…

Fertiliser burn (salt injury) occurs when chemical fertiliser is applied at too high a rate or too high a…

Light deficiency occurs when the rose does not receive enough light to photosynthesise efficiently. Roses need at least…

Nitrogen (N) deficiency occurs when the rose is not supplied with enough nitrogen — typically because the soil is poor,…

Root-knot nematodes (Meloidogyne spp.) are microscopic obligate root parasites (0.2–2 mm) of roses. They pierce fine…

Phosphorus (P) deficiency occurs when the rose is not supplied with enough phosphorus — one of the three macronutrients…

Root rot is caused by soilborne pathogens such as Phytophthora, Pythium, or Rhizoctonia. The fungi blacken and decay…

Rose Rosette Disease (RRD) is one of the most destructive diseases of roses (Rosa spp.), especially across North…

Soil pH imbalance — either too acidic (pH < 5.5) or too alkaline (pH > 7.5) — locks up many nutrients into forms the…

Sulfur (S) is often called the fourth major nutrient for roses, after nitrogen, phosphorus and potassium. It is a…

Waterlogging occurs when the substrate stays saturated for an extended period, depriving the root zone of oxygen. The…

Whiteflies (family Aleyrodidae) are not true flies but close relatives of aphids and mealybugs. They are tiny insects,…