Watering
Banksias: During the big drought (2002/early 2003) the plants in our
garden survived remarkably well. Banksias were the exception. We lost a number
of specimens in the extremely dry conditions. Banksias have an adventitious
root system (similar to grasses except on a larger scale). Most native plants
have a long taproot that is able to access water at sub-soil level. Banksia
roots may not penetrate to these depths particularly with young plants. Also
Banksias have leathery leaves that maintain their shape and do not wilt when
the plant is under water stress. By the time we notice their discomfort the
plants are usually dead.
We decided to try to deliver water directly to the plant’s roots. Each time
we plant a Banksia a length of plastic polypipe is planted beside each Banksia.
We are using 37mm (1.5in.) polypipe and each piece is 30 cm (12in.) long. The
pipe is placed beside the plant with about 15 cm., sticking out of the ground
(see image). In this case the pipe is accompanied by a Banksia serrata.
We also build up the soil and mulch around each plant to form a
saucer-shaped depression. The idea is to fill the pipe with water each time
the new plants are watered and also mature plants will be watered, using this
method, during dry periods. Hopefully this watering system will allow our
Banksias to survive and thrive. It
is more horticulturally pleasing to see green-foliaged Banksias than specimens
with brown leaves.