Scientific name and introduction
Asparagus spp. Asparagus fern (A. setaceus and other species in the genus Asparagus) are probably better known in the floral trade as A. plumosus or plumosus fern, and provide an interesting foliage and filler for arrangements. These species are not true ferns but are members of the lily family, in the same genus as edible asparagus. Asparagus densiflorus ‘Sprengeri’ group is another common filler foliage.
Quality characteristics and criteria
As with other foliage, asparagus fern should be harvested when the fronds are fully mature – immature tips are very likely to wilt after harvest. Make sure that the fronds are mature, uniform green, that there are no yellow leaves, and that leaves do not fall from the frond when they are shaken.
Grading and bunching
There are no formal grade standards for asparagus fern, but fronds should be intact, of uniform length, maturity and colour. Fronds are frequently bunched in groups of 20, and not normally placed in sleeves.
Exposure to ethylene will cause leaf fall in some species of asparagus fern, and therefore pre-treatment with 1-MCP or STS is beneficial.
Because ethylene exposure will cause accelerated leaf fall, treatment with 1-MCP or STS is recommended.
Store asparagus ferns at 0° to 1°C, wrapped in polyethylene to reduce drying out during storage. The ferns should be cooled before being wrapped in polythene.
Packing: Because of their relatively low value, asparagus and other ferns are packed densely in boxes – usually horizontal boxes that are filled as full as possible. This places an additional emphasis on the importance of pre-cooling, but no paper or plastic is used, which permits reasonably effective forced air cooling.
Asparagus fern suffers from premature leaf fall. Induced primarily by water stress, it can be a serious problem. To avoid yellowing and leaf fall, avoid prolonged storage. Certain preservative solutions aggravate premature leaf yellowing. However, preservative should be used in all arrangements containing this fern, as other items in the arrangement will benefit.