Plant Doctor Archive

Rust in Roses

I am a very new gardener and last year launched into roses in a big way. I was rewarded with gorgeous big flowers. I sprayed every two weeks and thought it was easy. This year, however, disaster! One whole section of roses is covered in unsightly rust - it's very bad - the flowers are stunted and malformed and the leaves orange. I had been spraying fortnightly since the first leaves appeared, alternating between Super Shield, Gild or Saprol.

RUST can definitely make roses unsightly and set them back, but don't give up. Saprol and Gild are similar in fungicide chemicals, with Gild having the advantage of killing insect pests as well. Keep spraying, alternating between Super Shield with Saprol, Greenguard or Bravo. Add a wetting agent with Super Shield and Saprol. Water either early morning or late afternoon - in my experience this reduces the risk of fungal problems. Come winter, prune your roses and discard prunings and leaves that have fallen around the plants.

Plan a winter spray programme using Copper Oxychloride and Conqueror Oil to protect the plants and kill off any fungal spores that are present. Keep this up through next spring when new growth starts to develop, then swap to your usual spring/summer spray programme. Watch that the new growth doesn't get spray burn and everything should come up roses!

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