Tag Archives: Tikorangi winter

Escaped root stock

Many years ago, neighbours planted a row of flowering cherry trees on their roadside. Mark and I were discussing how long ago and he thought somewhere over 30 years, maybe even more. I recall when they first went in and they struggled for at least the first decade. There used to be quite a few more but these are the survivors.

We are not good territory for prunus and these were in a particularly exposed situation – windy, in other words. They may not have been planted very well but that is just a guess. To add insult to injury, I asked Mark if he could remember seeing them flower because it suddenly occurred to me that I had no memory of them in bloom yet we drive past them every time we leave our property. He couldn’t remember either so I guess we can conclude that the flowering is not anything remarkable at all, possibly occurring at the same time as the trees leaf up for spring. I shall try and take more notice this spring. They do at least colour up in autumn.

Two different growth forms on the same plant – one upright and one spreading

We can’t identify the variety but it is clearly not well suited to our climate and conditions. However, it is a named cultivar because these are grafted plants. How do we know? Take a look at this one in the row. It has the same spreading form as all the others but in the middle is this upright shape. That is escaped root stock.

There are many reasons for budding or grafting onto the roots of another plant. Some selected varieties don’t grow well on their own roots or can’t be struck easily from cuttings. Depending on the chosen root stock, it can either increase the vigour of the plant or it can dwarf it and slow it down. Fruit trees are often put onto dwarfing stock. If material of the chosen cultivar is in short supply, budding or grafting can make it go a lot further with a higher success rate in propagation. While it takes more technical skill to bud and graft than to take cuttings and the selection of appropriate root stock is very important, it is possible to get a higher percentage through the propagation process and to reach a saleable grade faster than from cuttings. Many plants are budded or grafted, Budding, by the way, is usually easier than grafting. Once the bud or graft has taken successfully, the original growth from the root stock is removed entirely.

When I looked at the base of the plant, it was clear that the upright section all came from one strong shoot close to the base – outlined here in red

Problems come when the root stock puts up a shoot that is allowed to grow and that is what has happened to this tree. Occasionally we get asked why somebody’s magnolia has two different types of blooms (one that flowered both yellow and pink comes to mind). It is always escaped root stock and while it may have a certain novelty value, it does not make for a good long-term plant. The root stock – which is commonly grown from seed and only chosen for its strong growth and good root system – on most plants is stronger growing and it will overpower the chosen plant variety in time.

I think this cherry tree may be well past the time when removal of the escaped root stock is an option but, to be honest, when the cultivar isn’t worth growing anyway, this may not matter much in the greater scheme of things. But I recommend that if you ever see strong growths rocketing away from the base of a tree or shrub, it may well indicate that the plant has been budded and it is best to remove escaping root stock when it is young.

Winter in Tikorangi

Finally, because it is indubitably winter here now, being June, I give you a Tikorangi winter. Vireya rhododendron ‘Jiminy Cricket’ in full bloom with a mandarin tree and Braeburn apple. It was this very mandarin tree that convinced me to live in Tikorangi. In my Dunedin childhood, the occasional bag of somewhat green, expensive mandarins was always seen as a treat. Tinned mandarin segments were reserved for decorating the Christmas pavlova. This tree showed riches the likes of which I had never seen before.