Heard today from a gardener about daylily rust … and when I went into Palmer’s at Bethlehem to catch up with manager Laurie Jeyes and mentioned it, he said the problem in this area started last year and he had “queues” of people wanting to know what to do.
Choices for treatment are few as there is only one systemic spray for the prevention of rust on the market. According to Laurie, the key ingredient is Saprol, “a protective” spray against fungal diseases, ie, it needs to be used before a problem becomes apparent. “They’ve stopped bringing in the curatives,” Laurie says, “because they weren’t selling enough.”
People who prefer an organic solution could try a sulphur spray as a preventative, Laurie says, suggesting it will act like a disinfectant should the wind-borne spores land.
One gardener told me that it seemed only hybrid Hemerocallis were affected and Laurie said he particularly noticed the rust last year on public plantings of daylilies and wonders if the disease, which turns the leaves brown, will see these (up to now) easy-care plants go out of favour with councils, landscapers and home gardeners.
This Whangarei nursery specialises in daylilies and offers some thoughts on rust prevention and cure at the bottom of the page, including using seaweed or fish-based fertilisers to strengthen plants. Jack Hobbs, curator of Auckland Regional Botanic Gardens, meanwhile has been quoted as saying he is thinking about breeding rust-resistant plants.
Laurie also mentioned a couple of passionfruit diseases that are driving gardeners to distraction – grease spot (a bacteria) and septoria blotch (a fungus), the latter causing fruit to wither and fall, as well as the collapse of the plant as a whole.
“People should treat their passionfruit like tomatoes and potatoes,” he says, “and put a preventative copper spray on. Without control, the disease will kill the plant.”
Go to this website for further information, although note that it is aimed at commercial growers of passionfruit.