Pruning
Pruning is an important management practice used for cultural improvement and productivity in horticulture and has a number of benefits in:
- improving in yields
- producing of high quality blooms
- extending the commercial life of each bush
- improving plant structure
- disease control
- improving manageability and harvesting.
It is important to observe the growth habit of each species, the flowering period and initiation, and stem length required. All pruning equipment should be disinfected during pruning and prunings disposed of afterwards.
The time of pruning depends on floral season of a species in the region where it is grown. For many banksias flowers for the next year are formed within the stem well before they appear as buds and flowers. For some banksias such as B. coccinea it takes 12 months for flowers to develop while in B. baxteri it takes four months. For most banksias this means pruning as soon as practical after harvest, while flowers are fresh (Table 3).
For B. coccinea the following year’s flowers are initiated towards the end of current year’s flowering in November and should be pruned soon after harvest.
B. menziesii should be pruned after August. However, this may vary and careful observation and research by the grower is required to ascertain performance in any given location.
Table 3 Development stages and pruning time of Banksia species
| Species | Floral inititation | Flowering appearance | Development time (months) | Recommended pruning time |
|---|---|---|---|---|
| B. ashbyi | Nov | Apr-Aug | 8 | Two forms of this selection. Northern form has lignotuber and can be pruned harder than the more southern non-lignotuber form. PRUNE AFTER HARVEST |
| B. baxteri | Sept-Nov | Dec-Mar | 4 | No lignotuber. There is a significant amount of time between completion of one year’s flowering and initiation of next season’s flowers All pruning must be completed BY MID APRIL |
| B. burdettii | Oct-Dec | Jan-Mar | 8 | No lignotuber All pruning must be completed
PRUNE AFTER HARVEST |
| B. coccinea | Nov | Jul-Nov | 12 | No lignotuber The following year’s flowers are initiated towards the end of current year’s flowering. PRUNE AT HARVEST/POST FLOWERING |
| B. hookeriana | Dec-Mar | Apr-Oct | 9 | No lignotuber Floral initiation occurs in early summer. Flowers on two year old shoots
PRUNE AFTER HARVEST |
| B. menziesii | Sep-Nov | Mar-Aug | 8 | Has lignotuber. Can be pruned harder. Floral initiation from September to November.
PRUNE AFTER HARVEST |
| B. prionotes | Oct | Mar-May | 6 | No lignotuber All pruning must be completed
PRUNE AFTER HARVEST |
| B. speciosa | Sep-Oct | Oct-Feb | 12 | No lignotuber Flowering occurs all year round. Peak occurs Oct – Feb PRUNE AT HARVEST/POST FLOWERING |