Postharvest treatments
To maintain the best quality, banksias should be harvested in the cool of the morning and moved into the packing shed as soon as possible to avoid blooms heating up and dehydrating.
Banksias are preferably picked when no more than 20% of florets open along a bloom. Picking later results in some of older florets drying on the flower, reducing the fresh look. Banksia leaves dry quickly and can’t be readily re-hydrated. Florets are quickly dried if left in the heat for short periods.
This greatly reduces the freshness of flowers and their saleability. To avoid this, banksia stems should be stood in water at the earliest possible stage. Harvesting should be managed to avoid gluts that lead to stems being left in a heap on the packing shed floor.
Galls on leaves are unsightly and these stems should be culled from harvest. Once in the packing shed the lower 15 to 20cm of leaves should be stripped from stems. This can be done using a machine designed for the purpose. Stems are then graded and re-cut to length and stood with stem ends in 10 cm of clean cool water (20ºC). About 50-100 ppm of chlorine in water can be used if necessary.
Banksias do not respond to the floral preservatives of biocides or sugar or require anti-ethylene treatment.
They are generally not bunched but packed and sold as individual stems.
Buckets containing banksias should be moved into a coolroom at 1-4ºC as soon as possible after processing. Stems should be moved to markets rapidly although banksias can be cold-stored.
Banksia prionotes stores well over four weeks provided the blooms were dipped in fungicide and a high humidity storage atmosphere was maintained during storage, such as use of plastic bags. Alternatively, wet newspaper has been used.
The storage life of banksias depends on the quality of flowers, age and species. Before attempting to store large quantities of flowers, test batches commercially. Ideally the cool chain should be maintained to markets.
If banksias are to be sold dry, they should be tied in bunches and hung upside down in the roof of a dry shed to allow quick drying.
Acknowledgement
This article was developed from original work by Kevin Seaton, Bill Woods and Aileen Reid (DAFWA), Gerry Parlevliet and Max Crowhurst, Digby Growns (all previously DAFWA) and the Banksia industry.