Plant Doctor Archive

Rust on freesias

THIS year my freesias have succumbed to what looks like a rust disease, leading to leaves dying and poor flowering. Usually there are masses of flowers for weeks. It hasn't affected the sparaxis which grow alongside. Any help you can offer would be appreciated.

I HAD not heard of rust affecting freesias before so I checked with bulb expert Paul Hoek, of Aorangi Bulbs, who says it is relatively rare. He suggests it is probably a generic rust disease, possibly a secondary infection following on from damage by botrytis or thrips and encouraged by wet weather coupled with warmer spring temperatures. So there's a good chance, given more favourable weather, the problem may not occur again next year.

You could reduce the risk of overwintering disease spores by spraying the foliage before it dies down with a fungicide such as Fungus Fighter or Greenguard. Spray again next spring at the first sign of the disease, should it reappear.

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