Burrendong's Hakeas
Marion Jarratt
Note: This article originally appeared in 'Brigge', the newsletter of the friends of Burrendong Arboretum. The Arboretum is located in the central west of New South Wales, near Wellington.
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The Hakea collection has always been a strength of Burrendong Arboretum and they are so typically Australian - of the 150 or so known species all are endemic to Australia - that it seemed a good idea to write about them. Evidently of these 150 species only 130 are named and botanical revision is providing names and descriptions for about 20 new species. Very important to keep the taxonomists busy!
Hakeas are wonderful garden plants. Their often stiff and often prickly leaves can be most off putting to unwelcome guests such as cats and dogs and [probably] people! But the same unyielding foliage provides a striking contrast to the softer, often pendulous foliage of wattle, bottle brushes, some grevilleas and many exotics. It also provides a safe haven for small birds for nesting, or resting while the flowers provide copious nectar and are eagerly sought after by honeyeaters. And there are some very graceful hakeas with an open, pendulous habit.
In addition to all these welcome attributes, hakeas flower in winter when so many of our gardens are looking a bit ordinary and they flower extravagantly with great spikes or clusters of blossom in rich or delicate colours. They are also some of the easiest of our native plants to grow since they adapt to a wide range of climatic conditions and soil types.
Reference to a couple of local nurseries indicated that the number of different species they had for sale is very limited but possibly sales by ASGAP groups would yield a greater variety. Most of the Friends of various Botanic Gardens grow plants and these would probably include natives and there are a number of native plant nurseries around which would probably have some of the species I am going to write about.
We currently have about 80 species of Hakea in the Arboretum. They include the well known ones such as the Royal hakea (H.victoria), the grass-leaved hakea (H.francisiana), and also some rare and unusual ones. So if you visit the Arboretum in winter make sure you don't miss H.corymbosa (the cauliflower hakea), H.victoria, H.cristata (the snail hakea), H.hookeriana (Barren Range hakea), H.pandanocarpa (the pineapple hakea), H.platysperma (the cricket ball hakea with wonderful fruit honestly the size of a cricket ball!) and, most important of all, H.lorea (the bootlace oak) which you will find at the end of the Wattle Walk]. All of these are quite rare in the wild or are ones you don't often see in eastern Australia.
More specifically, together with other Friends of the Arboretum, I have picked out a number of hakeas which you might like to have in your garden and have divided them up into foliage and habit, flowers, fruit and ones you can grow on the coast.
Hakeas with beautiful foliage or unusual habit
H.victoria, the Royal hakea from Western Australia, has erect stiff branches of variegated foliage which range in colour from cream, green and yellow to orange gold and red as they age. Backlit by the sun they look like stained glass windows. The species is best suited to growing in warmer, drier regions (it does not tolerate humidity) and requires full sun and good drainage. At the Arboretum they are grown on east facing slopes out of reach of heavy frosts, on very shallow soils.
H.baxteri, the fan leaf hakea, has broadly fan shaped leaves climbing gracefully up the branches. The flowers are rusty brown to dull greenish cream and strongly scented - but the attraction of this plant is in the shape of the leaves and its narrow erect habitat. Like most hakeas it likes freely draining acidic soils and sun but will tolerate some shade and moderately heavy frosts.
H.corymbosa, the cauliflower hakea (although I think it looks more like broccoli). This is definitely a great plant to add structure to a garden and is characterised by these wonderful dense curved heads of foliage which carry, when flowering, a conspicuous covering of greenish yellow flowers which are strongly and sweetly scented. It is best suited to a warm climates and lots of sun when it grows very compact. In shaded areas or cool climates it tends to develop an elongated and open habit. Drainage must be good but it will tolerate slightly alkaline soils. Cauliflower hakea will make a good hedge but I think a small group or even just one makes a wonderful fashion statement for a garden. They certainly make a stunning sight at the Arboretum on the Hakea Walk.
H.lorea or bootlace oak is a 'wow' plant in anyone's garden. This is a tall shrub to small tree with an open habit and long pendulous cylindrical leaves which may be up to 70 cm long and which fall vertically from horizontal branches. At flowering time large clusters of creamy flowers sit atop the branches so the effect is that of a bridal veil. This species is rare in cultivation and is slow growing. It is best suited to inland regions with a dry sunny climate. At the Arboretum we have one mature and absolutely stunning bootlace oak high on an east facing slope, well drained and out of reach of all but the heaviest frosts.
A somewhat similar species is H.fraseri or corkwood oak with the same open habit, long cylindrical leaves and large clusters of creamy flowers. It grows on the heavy clay loams of south-west Queensland. There is a lovely group of corkwood oaks on a west facing slope just below the Information Centre. These would be affected by light frosts but are in a sunny well drained situation. (As an aside, I was fascinated a few months ago to see a Frill Necked Lizard happily arranged on the highest branches of one of these. Whether he was after heat or food, I am not sure!).
H.cuculata or cup hakea, so called because its round to kidney-shaped leaves are distinctly cup shaped. The flowers are also attractive - profuse and pink - and the new growth can be very decorative. It is popular in cultivation and can tolerate extended dry conditions and most frosts but it must have good drainage. At the Arboretum it grows by the bird bath on the Hakea Walk.
Hakeas with particularly beautiful flowers
This is a hard one because so many of this genus have such spectacular flowers. Gay and Hazel suggested the following species.
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| Two forms of Hakea francisiana |
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H.francisiana is probably the most eye-catching of the hakeas when in full bloom. Against the silver-green fine leaves of this small tree the long plumes of flowers glow deep pink, orange or red. Lots of sun and good drainage are required for this species but it is tolerant of frosts. Grafting can enable H.francisiana to be grown in cooler climates and heavier soils. At the Arboretum you will find a wonderful grove of these at the start of the Hakea Walk.
H.grammatophylla is less well known but is a highly ornamental species from Central Australia. It is a dwarf to small shrub so is quite suitable for a small garden and, while best suited to inland with a semi arid climate, it is worth trying in other areas. The flowers are bright pink, showy and strongly scented. You can see this at the end of the Hakea Walk.
H.myrtoides is a dwarf, sprawling shrub which can tolerate some alkalinity. It is one of the most floriferous members of the genus and is an outstanding ornamental in temperate and semi-arid regions. The flowers are initially deep reddish to purplish pink but fade to a lovely pale pink. We grow it in the raised beds around the nursery at the Arboretum. As long as it has good drainage it does not mind moisture.
Hakea species with interesting fruits
I love these because you can enjoy the shapes of the fruit all the year round, and they are something the kids can really enjoy, too.
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Most hakeas have interesting and unusual fruits
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H.cristata, the snail hakea, has an attractive low bushy habit with colourful young growth, attractive leaf shape (although pretty prickly) and these marvellous woody fruits which look exactly like snails with their heads up and waving around. This lignotuberous species is quick growing and relatively unfussy in its requirements as regards soils and climate provided drainage is adequate and there is little humidity. In the Aboretum it grows freely along the Hakea Walk.
H.orthorrhyncha or bird's beak hakea, is another species with several attractive facets. The brilliant red flowers which cluster thickly along the stems and trunk make you think the plant is on fire while the distinctive fruit which look exactly like a birds head with a long curved beak will delight the kids. This plant does well in semi-arid and temperate regions and like most of the hakeas needs well drained soils and a sunny position but can tolerate some degree of frost. It grows most happily at the Arboretum in a number of areas. One drawback - it may not flower for the first 5-7 years of its life (but you can always hope!).
H.pandanocarpa. The pineapple hakea is a somewhat ordinary looking medium sized shrub with creamy-white, sweetly scented flowers but its pièce de résistance is its cork covered fruit which look exactly like pineapples. These may take some years to develop but are such fun it's worth the wait. It is actually a fairly adaptable species provided it is not subject to damp conditions.
Hakeas to grow in coastal climates
Not many of these, I am afraid, but there are a few.
H.clavata, the coastal hakea. The leaves are interesting in that they are the thickest of any hakea and succulent-like. The flowers, at the Arboretum anyway, open a delicate pale pink and white and are quite profuse as well as being sweetly scented. This species is confined to the coastal areas from Esperance to the Eyre Peninusula and is often exposed to salt laden winds. An ideal plant for an exposed, sunny coastal garden, it also grows well at the Arboretum in a sunny position in a raised bed near the Nursery.
H.dactyloides. The finger hakea grows in coastal districts and also in mountainous regions from south-eastern Queensland to eastern Victoria. The flowers are white and can be profuse but are not conspicuous. The plant itself can be used for hedging or screening purposes and responds well to pruning.
H.salicifolia, the willow-leaved hakea, is widely planted as an ornamental as it is tolerant of a wide range of conditions and can manage shallow to deep soils, dry to wet conditions and full shade to full sun (sounds too good to be true!). Cultivars can be bought from nurseries - 'Gold Medal' is a popular one. Here we have a wonderful grove of them on the Hakea Walk. Interestingly because of its tolerance to a wide range of conditions and its resistance to root-rotting fungi this species is an excellent rootstock for grafting.
And just to finish - a few cultivation tips......
- Don't overwater. When you plant out, restrict watering to a bucket to a bucket and a half every fortnight - in the hot weather - less if its cool or cloudy and after the first year very little water at all.
- Remember that many hakeas are prone to wind damage so unless you know for sure otherwise do not plant them in exposed, windy situations.
- Good drainage is very, very important. Raised beds or slopes are fine but not depressions or permanently damp spots (save those positions for callistemons or melaleucas).
From 'Brigge', the newsletter of the Friends of Burrendong Arboretum Inc., April 2004.
Australian Plants online - 2008
Association of Societies for Growing Australian Plants
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