At the Plant Sale and Flower Show today I took some photos of flower arrangements done in a form of Ikebana style. The very bold and brash Banksias and Waratahs featured in them all. The members of this particular flower arranging group have made floral arrangements for the last few Flower Shows. They certainly showcase these exciting flowers.
The photo above features Banksia spinulosa and Thryptomene. The Pavilion where this display was housed had all sorts of distracting features on the walls and around the cut flowers. It was quite tricky getting a photo which did not have too much in the background.
Banksia ericifolia is another of the Banksias flowering at Wittunga Botanic Gardens at the moment.
There are a number of quite old plants with thick trunks and leaning branches. Rather attractive. The flowers vary in size from 10-30cm long.
This plant can grow 2-7m high and 1-2.5m wide. It prefers good drainage. It would be a good plant for exposed coastal conditions and for windbreaks and screening. I have seen them in the Eastern states used as a large hedge where that screening effect is desired. It is affected by alkaline soil but could be helped by treating with iron chelates.
Banksia spinulosa (Hairpin Banksia) is a plant I have always admired. I have no hope of growing this one here successfully because it definitely does not like highly alkaline soils. This is another from the eastern states.
It is a medium to tall spreading shrub 1-4m high by 1-5m wide. The flowers have purplish black styles which can be seen in the photo, hence the name Hairpin Banksia. Again the honeyeaters love this one also as it is a prolific flowerer.
Today we had to be in Adelaide so came home via Blackwood and Wittunga Botanic Gardens. It is a few years since we had been there and a lot of new plantings have been done in the past 6 months.
Amongst the plants flowering were some Banksias. Surprisingly, from a rainfall point of view, Banksia integrifolia grows quite well here (13 inches). The rainfall at Wittunga would be nearer 24 inches I suppose.
Here it grows to about 5-6 metres. It can grow to as much as 20m. The leaves are attractive being dull dark green above and silvery below, with pale yellow flowers. In places it grows right up to the edge of sea water. Yet it is also frost hardy.
Here it grows on highly alkaline soils with good drainage. Limestone rubble in the soil at least ensures that! At Wittunga it would be nearer neutral to possibly slightly acidic.
I have come to the conclusion that once the temperature reaches 0C that it doesn’t matter how much lower it gets. Cold is cold! We should be thankful, I suppose, that at least the temperature increases during the day to being quite pleasant, and of course with the intense cold we get these beautiful blue sky days.
The information on Banksias is truly incomplete. Many books will state categorically that particular species will grow only in acid soils. Until they are grown in soils of different pH and tested, we do only have this information to rely on.
I have updated this post with a photo of a Banksia I would like to grow at home. This one is at the Arboretum where pH is closer to neutral.
One of my aims is to try a variety of Banksias, using additional sulphur if necessary. I originally wanted to grow only those plants which grew well in highly alkaline soils. The problem is that I want to see good growth on all the plants and want to intervene if necessary. I will still have the restriction of rainfall to contend with any way. Record keeping is the key to making this a useful exercise.
I certainly want to have Banksia coccinea and Banksia menziesii in the garden.