Plant Doctor Archive

Fungal fuchsias

ABOUT December, my fuchsias always get attacked by black spot. The leaves drop off and all that's left is a bare stem with a few leaves and the odd flower at the top. What should I do?

FUCHSIA rust is the problem - turn over the affected leaves and you'll see orange-brown, powdery spots on the lower surface. This disease is more prevalent in warm, humid weather, so is worse in summer. Some varieties are more susceptible than others - they don't all succumb - so you could dig out the stricken plants and replant with resistant varieties.

Check the labels at the garden centre and only buy fuchsias that claim to be rust-resistant. But remember resistance doesn't mean they are immune to the disease, only that they will be less rust-prone.

Here are some other tips to help reduce the problem:

• Grow your fuchsias where they get plenty of fresh air - prune other shrubs back if necessary to allow better air movement.
• If watering, avoid getting the leaves wet.
• When fertilising use a product with relatively high levels of potassium, such as rose or tomato fertiliser.
• Before the disease appears spray with a protective fungicide such as Super Sulphur or Bravo.
• If the disease is already present spray with a fungicide such as Fungus & Mildew Spray or Fungus Fighter.
• Use a combination insecticide/fungicide such as Gild or Super Shield (following label recommendations).

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.