Update: please see this comprehensive post about growing Albany Woolly Bush.
I’ve been asked for an update on the woolly bush hedge I planted behind my house. The back of my house faces west, very bad in terms of passive solar design, because when the back verandah was enclosed, some clever person put in a wall of windows. Every summer afternoon my back room bakes, lightly toasting the rest of the house. It’s a nice place to pass a sunny winter afternoon, but for half the year my house is unpleasantly hot. A hedge of locally endemic plants was my solution.
It hasn’t been five years, by which time my woolly bushes should be fully grown, but after almost four years, my hedge is well on its way. It’s not yet blocking the setting sun, but I love this green wall and it’s become a haven for wildlife. Red wattlebirds (Anthochaera carunculata) and singing honeyeaters (Lichenostomus virescens) love the nectar and it flowers for a large part of the year (July-January). Insects and spiders have taken up residence in abundant variety. My cat and dog think under (or on) the lowest branches is a great place to nap.
The Albany woolly bush (Adenanthos sericeus) is usually used in garden planting if you want a hedge. It’s more widely available in nurseries, easier to propagate and looks “prettier.” I used Adenanthos cygnorum, a species endemic to Perth which I bought from Lullfitz Nursery in Wanneroo. What I didn’t realise was this species can grow up to 4m, but may be low growing.* As my plants grew, two of them didn’t grow tall. I don’t mind because as I prune the tall woolly bushes they spread sideways and it’s above the fence that I want them blocking sunlight. My hedge is just a bit unusual.
If you’re growing a hedge for aesthetics as well as enclosure, I recommend the Albany woolly bush. It’s available from most nurseries so you won’t have to go to a specialist native plant nursery. If you want a lower growing hedge (waist height) use Westringia. There are a number of Westringia species but the Perth endemic Westringia dampieri grows well in our sandy soils. I have one in my garden and it looks very much like rosemary, but with pretty white flowers.
Native species should be planted at the start of winter, with some non-phosphorous fertilizer (eg. sheep manure). The rains of winter get them off to a good start, but in their first summer they will likely need some watering (once or twice a week). After their second winter, woolly bush and Westringia dampieri shouldn’t need further watering or fertilizer because they have evolved with our dry climate and nutrient poor soil. If the winter is dry or you’re planting at other times, the plants will need supplementary watering, every day during the hot summer. While many native plant species are drought tolerant, not all are. It’s best to choose locally endemic species if you don’t want to have to water or fertilize.
Woolly bushes look very like Christmas trees, so prune some branches before Christmas and put them in a bucket of water for a living Christmas tree. It doesn’t matter that it won’t be after the flowering period, woolly bushes are tough and you can prune them any time of year, whenever they’re growing out of the hedge shape you desire.
Someone asked if woolly bush roots grow into underground pipes. They have shallow root systems and I’ve never heard of this. I have an Albany woolly bush (not part of my hedge) growing next to the garden irrigation solenoids. The roots of palm trees cause problems with these pipes, rather than the woolly bush. My pond is also next to this woolly bush and the roots have never caused problems with the hard plastic lining.
If you want to ask a question about growing woolly bush please comment on this more recent post Albany Woolly Bush.