Plant Collector: Vireya Rhododendron Rio Rita

Large, luscious and fragrant - vireya Rio Rita

Large, luscious and fragrant - vireya Rio Rita

Rio Rita was bred by the late Os Blumhardt, one of this country’s foremost plantsmen and plant breeders in his time. It was named for the irrepressible Rita Watson and it always makes us smile because the flower is so well suited to the bold personality and immaculate grooming of the namesake. Rita was very keen on vireya rhododendrons and her North Shore garden boasted some of the best grown plants we have ever seen in a garden situation though we were told she subsequently gave up growing vireyas and took up line dancing instead. Rio Rita is a leucogigas hybrid (crossed with Dr Sleumer) and the flowers are voluptuous and fragrant. There are five flowers to a truss and this photograph is of two trusses side by side, which is why it looks quite so full. Each flower is about 10 cm across, which is large.

Most vireyas don’t have a set flowering season because they come from the equatorial areas where day and night length is pretty much the same all year. This means you can have some in flower all the time if you have sufficient plants and different varieties. However, they won’t tolerate more than a degree or two of frost and wet feet will kill them very quickly. As a guide, the bigger and more lusciously fragrant the flowers are and the larger the leaves, the more susceptible they will be to cold temperatures and less than ideal conditions. This means that Rio Rita is by no means the easiest vireya to grow well, let alone keep alive at all, but if you have the right conditions, it certainly puts on a show.

In the garden this week: Friday April 29, 2011

Prunus serrula would have been better kept to a single leader when it was a young plant

Prunus serrula would have been better kept to a single leader when it was a young plant

• Get any spring bulbs planted without delay. They need to be growing now to give you the anticipated display later.

• Rhubarb is a clumping perennial and benefits from being lifted and divided. It is a gross feeder and likes really well cultivated soil. So double dig the area (dig, then dig again) and add plenty of compost before replanting big divisions.

• Broad beans can be planted now for harvest in spring. Picked when young and tender, they are truly tasty. If they get away on you and go old and tough, dry them. They are also known as fava beans and are delicious when soaked, skinned and used in bean dishes or added to falafel.

• A reminder to get your strawberry runners planted without delay so they can get established and build enough strength to start cropping on cue in spring.

• It is only tradition that says garlic should be planted on the shortest day of the year. We have had good success planting considerably earlier, in May. The plants are stronger and better able to withstand the very wet early spring weather we can get here when temperatures are still cold. If you are going to plant your garlic early (and long keeping brown onions can be done at the same time), prepare the ground now. Dig it over well, adding plenty of compost and maybe some animal manure. Then leave it to sit for a few weeks before planting. These crops need excellent drainage, but they do better when the soil has settled a little rather than being freshly fluffed up.

• It is good pruning and shaping time on woody trees and shrubs (though best done when the overhead branches are not showering you in water). A good pruning job is when it is not clear by looking at the plant where you have been, despite the mountain of branches on the path beside you. Rather than hacking the entire bush, being selective about which branches you remove or shorten and cutting flush to the main stems makes a big difference. However, there are times when drastic action is required – such as the shabby camellia in Outdoor Classroom this week.

• Most trees are best kept to a single leader – one trunk. Where a trunk is forked near the base, it is a structural weakness in the tree which can lead to it eventually splitting apart. The earlier this is done to a tree, the easier it is to train what remains to a good shape.

Renovating old camellia plants: step-by-step

1) Camellia sasanqua “Sparkling Burgundy” has had quite a bit of work done on it over the years to thin the branch structure and to lift the lower levels to allow light below. This has made a feature of the size and age of the plant which is now more of a small tree than a shrub.

2) However, this camellia has little in its favour. The top layers of foliage are not in good health and look scruffy and full of dead wood. We will rejuvenate it by cutting it back very hard to bare wood. This is best done any time from through winter until early spring.

3) The plant is virused which affects its vigour. Virus in camellias is not always bad. It is what gives variegated leaves and two tone flowers. However, if you then use the cutting tools on a healthy camellia, you will transfer the virus. It pays to disinfect saws and secateurs immediately after finishing the affected plant. You can do this by simply dipping in a bucket containing diluted bleach.

4) Cut back to whatever level you wish. Most camellias will resprout and come again even when cut off at ground level, but we want a bushy shrub about 1.5 metres high by summer so we are leaving bare woody stems around that height, cut a little lower at the sides than the centre. If you leave some of the old trunks, you keep a strong structure and shape for the bush. If you cut off at the ground, you will be starting over with a carpet of fresh shoots which may not give a good long term shape.

5) This Camellia yuhsienensis was cut back early last spring to completely bare stems with not a single leaf remaining. Such ruthless cutting forced dormant leaf buds into life and it is now a bushy little shrub although we won’t get as many flowers as usual for another year.

Tikorangi Notes: Monday April 25, 2011

Tree hydrangea of uncertain classification

Tree hydrangea of uncertain classification


This wonderful tree hydrangea is a sight to behold down our avenue gardens this week. I say tree because the plant is now about five metres high. The flowers are enormous – fully 45cm across each individual head but most things about this plant lean to the large. It is an unknown species (though currently classified in the aspera group, despite bearing little resemblance to most asperas) and fully evergreen. In NZ, it is commonly referred to as the Monkey Bridge hydrangea, collected in China. It is brittle, tender and very large – not suited to all gardens – but what an unusual delight in flower.

Tikorangi Notes: Saturday 23 April, 2011

Our identified woodland mushroom in a fairy path

Our identified woodland mushroom in a fairy path

Latest posts:

1) Paradise Found in New South Wales– or our attempts to find gardens to visit around Sydney from bats at the Bot Gardens to Bob Cherry’s dreams in Kulnura.

2) Plant Collector this week looks at two tidy, compact evergreen shrubs with berries: Ilex cornuta “Burfoodii” and Raphiolepsis indica “Enchantress”.

3) Garden tasks for the week as autumn marches on inexorably. Still, we have only had one really cold day so far.

Tikorangi Notes: Saturday 23 April, 2011 When it comes to wild fungi in New Zealand, we are terribly conservative. Generally it is only the field mushroom that is harvested for eating, although the magic mushroom used to attract experimental youth in search of a free hallucinogenic experience. Possibly it still does, but there are a host of other wild mushrooms that go untouched. I have bought the up to date publications on fungi found here, but it appears that nobody has done the work on which forms are edible. I am not so keen on doing the experimental taste test. Apparently the basket fungi, puffballs and elephant ear fungi are all perfectly safe to eat, but I want a definitive tome to tell me which are safe and delicious before I get adventurous. With death caps also common, the gap between fatal and edible seems a little too small to me. And we can’t even get an identification on this woodland fungi from our books. Cascading down through our tawa bush, these mushrooms are currently abundant and growing, not so much in a fairy ring, but more akin to a fairy path.