How to grow Phormiums from seed

Phormiums are a fantastic ornamental foliage plants and cope surprisingly well in almost all soil types and conditions so long as they get plenty of sun. They are also tolerant of maritime exposure and industrial areas. Despite the large number of differing cultivars around there only in fact two species within the genus Phormium - Phormium colensoi (formally cookianum) and Phormium tenax.

How to grow Phormiums from seed
Both species are native to the north and south islands of New Zealand' Phormium tenax is strictly a coastal cover plant while Phormium colensoi has separated into two distinct geological forms identifiable by the obvious location and flower colour. The first form is restricted to the lowland regions of the North Island and displays yellow blooms, The second inhabits the mountainous regions of both islands and displays red blooms. When growing in northern European gardens both are arguably as hardy as each other and will be fine kept outside in the south and southwest of England and Ireland. Winter protection will need to be considered further north as both species can be killed off during unseasonably cold british winters.

Both species will grow true from seed, but be aware that Phormium tenax flowers more freely than Phormium colensoi (meaing fewer if any seeds), and when cultivated forms are used the resulting seedlings are unlikely to grow true to the parent plants. After flowering, the seed pods will naturally dry dry and open to release the seed. The easiest way to collect the seeds is to place a bag over the seed pods just before they open (this is best indicated by the pods turning black) and come back a couple of weeks later to collect the seed. If your timing is out then just place a bag over opened seed pods and shake to dislodge the remaining seeds.

How to grow Phormiums from seed
You can sow Phormium seeds in Autumn (Sept to Oct) or if you miss this period you can have another shot during the Spring (Feb to April).

Using deep 9cm pots, fill with a good quality compost such as John Innes 'Seed and Cutting'. Consider adding horticultural sand to improve the drainage further.

At a rate of one seed per pot, press the seed into the surface (do not bury) and then cover with a thin layer of horticultural grit or vermiculite. Gently water in and then place the pots inside a heated propagator at a temperature of between 18-22 degrees Celsius. Keep the compost moist at all time but avoid waterlogging. Be aware that germination can be erratic, taking from between 30 to 180 days.

As each seedling emerges remove from the propagator and grow on in a bright, frost free position but one which is out of direct sunlight. Once the root systems have established in their pots they can be potted on and hardened off over 10-14 days to direct sunlight. Overwinter in a greenhouse or cold frame during their first winter.

Plant them out into their final positions in the following spring once all risk of late frosts have passed.

Click onto the above image for the 'Seeds of Eaden' seed shop
Main image credit - Pixabay under the Creative Commons CC0 1.0 Universal Public Domain Dedication
Phormium seeds - Roger Culos CC BY-SA 3.0

For related articles click onto the following links:

No comments: