Tag Archives: Outdoor classroom

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.

A step-by-step guide to staking and tying plants

1) If you can avoid staking a plant, do so. A plant can rely on the stake and not build the strength to hold itself up. If your plant has a small root system and too large a top (referred to as the sail area because it catches the wind) reduce the volume of foliage and branches to cut back the sail area.

2) This is heavy duty staking carried out on landscape grade plants put in to a windy situation on a road verge. Two, sometimes three or even four tanalised batons are used with wide ties. This allows some flexing of the tree without it blowing over and the stakes will last for several years. The flexing of the tree in the wind encourages it to develop a natural taper to its shape which gives it strength. To allow this flexing, the ties should never be more than a third of the way up the tree. All this staking will be removed when the tree has developed the root system and strength to hold itself up.

3) Avoid tying with string, rope or wire which will cut in to the bark and cause damage, potentially ring barking the trunk. For the home gardener, old pantyhose or strips of stretch fabric are commonly used or you can buy balls of interlock fabric tie at garden centres which are cheap and easy to use. Black, grey or muted green are less obvious in the garden. Strips cut from old inner tubes are another traditional tie.

4) Commercial growers use tying machines called tapeners which staple a flexible plastic tie in two movements so they are quick to use. However the tape does not break down in the garden situation so we avoid using a tapener except in the nursery because we don’t want little bits of black plastic through the garden.

5) Never force a stake hard in by the trunk of the plant, large or small. If you do this, you are damaging all the roots on that area of the plant, usually severing them entirely. If you think of the roots like a piece of pie or an umbrella, you are potentially damaging an entire segment of the root system. How far out you place the stake depends on the root system but even a couple of centimetres can make a big difference on small plants. You can see in the photo how much more damage the stake near to the stem will do compared to the one a little further out.

6) Bamboo stakes will usually last about a year before rotting off at ground level and this is often long enough for a plant to get established. Tanalised batons are a better option for longer term staking such as the trees in step 2 which will need stakes in place for up to 3 years. Where semi permanent staking is required for plants such as standard roses, metal stakes gently rust and become less obvious over time than other options.

Tikorangi Notes: Friday July 9, 2010

1) July 7, 2010: Vireya rhododendron saxafragoides is flowering this week – a distinctly obscure and different vireya species.
2) July 7, 2010: In the garden this week (and why citrus and avocado are essential home orchard trees here)
3) July 7, 2010: Bravely attempting to demystify rose pruning in our latest Outdoor Classroom.
4) July 7, 2010: Counting down to our annual Taranaki Garden Festival.
5) July 3, 2010: Camellia Diary number three where we celebrate Camellia Waterlily, a cultivar which I think could be described in the vernacular as an oldie but a goodie.

Rhododendron augustinii - a bit of a triumph in our climate

Probably the most exciting aspect of our gardening environment is the huge range of plants we can grow here. We have never been able to understand the mindset of those who favour mass plantings and the so-called restrained plant palette. Mark has been known to ask why on earth anybody would want to mass plant when there are so many interesting plants in the world to grow. So our mid-winter garden pictures this week are of Rhododendron augustinii and zygocactus.

The winter flowering chain cactus - more fun than polyanthus

I am not sure which form of augustinii this is (possibly the Medlicott form) and frankly we are just delighted that it is still alive with us because it much prefers a colder climate than we can give it here. On their day, you can not beat the species and augustinii is one of the loveliest species of all. The bronze beetle attacks the foliage (pretty well every leaf outside the photograph is notched all round), thrips can turn the leaves silver and there are smarter, neater garden plants but we rejoice when those lovely blue flowers appear each winter.

By way of contrast, the exotica of the chain cactus or zygocactus (schlumberga?) lightens up the dark woodland areas and is maintenance free and undemanding. We grow them as epiphytes, nestled into forks of trees or positioned on top of tree fern stumps. They have to be frost free and are generally grown in house plants throughout the world and they add a splash of cheering winter colour which I prefer to polyanthus.