Myrtle rust can travel with nursery plants, and sneaky spores

A recent report of myrtle rust on Bartlett's rātā (Metrosideros bartlettii) plants shipped from a nursery reminds us that, sadly, the disease can travel and potentially be introduced to new places with nursery plants. It is possible that symptoms were not visible at the time the plants were packed. It's the time of year when myrtle rust is rife, especially with all the wet weather some of the country has been having keeping leaf surfaces moist while the temperature is warm, so do keep an eye on any new Myrtaceae foliage - whether the plant has recently arrived at your place, hangs out in a pot on the deck, or is established in the garden. Avoid encouraging new growth by keep the pruning shears in the shed for now.

I have heard from a gardener who was surprised that their pōhutukawa seedlings had myrtle rust, even though they were located in a greenhouse. Unfortunately the spores of the fungal pathogen are highly mobile and can easily sneak around. If you are raising Myrtaceae in a greenhouse, the key thing to remember is to keep the foliage dry - the fungal spores can not infect without water. Therefore, water very carefully and only at the base.

We now also have a record of pōhutukawa fruits being infected on a large mature tree at an Auckland park, adding to evidence that this species is being increasingly impacted by myrtle rust - also being shown by the records posted here. What's the number one thing you can do for our native taonga suffering from a rusty onslaught? Avoid planting exotic Myrtaceae, especially Syzygium species often sold as 'lilly pilly', and Lophomyrtus plants, in your garden. If they are already there - and especially if they are infected - plan to replace them with something not susceptible to myrtle rust.

Publicado el 23 de febrero de 2022 a las 04:03 AM por reneejohansen