Tag Archives: shooting root stock

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.

 

Tikorangi notes: Iceland poppies are not from Iceland, naturalising trilliums, bluebells and escaping root stock

I have never been a fan of Iceland poppies. They were the one flower I remember my mother buying  when I was a child – a bunch of stems still in bud. She would burn the stems and then put them in a vase where they would open to what seemed garish and unappealing flowers to me. Tastes change and in recent years, I have found my eyes drawn to mass displays of these simple blooms. This patch is on a traffic island which holds the very modest clock tower in my modest local town of Waitara and it makes me smile when I pass.

The Waitara clock tower in a traffic island 

Ironically, on the opposite corner was this stand of fake flowers outside a Gold Coin shop.

Iceland poppies do not come from Iceland. I finally checked and in fact they come from the chilly areas of Europe, Asia and North America – sub polar territory, so presumably alpine meadows.  In the wild, Papaver nudicaule  (nude because of its bare stem which makes it a good cut flower) are pretty much all white or pale yellow. The other colours are recessive genes which have been brought out by plant breeding – presumably line breeding which is selecting down the generations of individual plants to pick out the stronger colours until those coloured genes have come to the fore.

Puketarata Garden near Hawera

This is not a plant I have ever felt the need to grow myself but there is a simple appeal to a mass display. I remember being quite charmed by their use in the clipped buxus formation at Jen Horner’s garden, Puketarata, one spring. It is hard to beat the simplicity of a single poppy, or indeed a daisy flower.

This poor little white one survived being taken off at the base with the strimmer last spring

These trilliums represent a minor triumph in Mark’s experiments with plants he can establish in meadow situations. We have plenty of trilliums in our woodland gardens but establishing them in a cultivated garden is different to getting them to naturalise on his bulb hillside. When I say “naturalise”, I mean that they are now sufficiently well established to return each year, able to compete with the grass and uncultivated soil. They are not actually increasing yet but they are at least established.

Mark has raised more seed and has about 70 pots of them in flower in the old nursery area. He is disappointed that most of them have come up white and said that he wants the red ones for planting in the meadow and he asked that the pale yellow ones be kept together as a group in one area. For him, this is all part of blurring boundaries in gardening again. He really likes the idea of trilliums thriving in managed garden conditions and then, as the garden becomes looser and more informal further out, the same plants popping up as wild flowers. Especially when it is something as choice as trilliums. Maybe I could surprise him with the surplus Paris polyphylla making an appearance on the bulb hillside, too.

I photographed this small flowering growth on Prunus Pearly Shadows as an example of unwanted root stock shooting away, even on a very well-established tree. Many plants are budded or grafted onto other rootstock so that the desired cultivar can utilise the strength of strong growing root stock. Which is well and good when the rootstock is compatible and doesn’t escape. If you don’t cut off the root stock, it can overwhelm the grafted selection so it is best to see to it as soon as you spot it. How do I know it is rootstock? It is a single white; Pearly Shadow is a fluffy pink double and is not yet in flower.

Prunus Pearly Shadows

This particular tree is a splendid example of what is described as a ‘vase-shaped form’. It has not been shaped. It grows naturally in that upward Y shape. It is in our car park area and has so far attracted three reversing cars. I am not quite sure how people fail to see it in their rear vision mirrors.

It is peak bluebell time in the park and even if these can be weedy, the drifts of colour are very pretty. Bluebells should, in our opinion, be predominantly blue. But the addition of a few white or pink ones amongst the blue gives a contrasting accent of colour that can lift the blue. The pink is also a strong grower, the white less so. We don’t want bluebells everywhere so I am removing them from some areas of the garden they are attempting to infiltrate but we are happy to let them spread in our meadows.