Thursday, 24 November 2011

Putting in the graft

Today was planting day for my Anniversary present. Although our date is in October, the tree was despatched to suit its best planting time so arrived this week, mid November. The variety is Concorde, an eating Pear and , as is the norm, is grafted on to a rootstock. In this instance, it's Quince. Grafting plants is a practice which it is thought goes back to the Chinese pre 2000BC. The main purposes for grafting are restricting top growth, rapid introduction of new varieties (by topworking) and to enable the cultivation of a variety that is susceptible to either disease or conditions such as temperature. The basic principle is forming a union at tissue level of two separate plants,usually those parts below ground (rootstock) and those above (scion). Find out more here. My major influence in horticulture, my maternal Grandfather, had a few grafted plants in his garden, including a three variety Pear tree. This sort of grating can enable a small garden to provide a larger range of varieties in smaller amounts than from three individual trees.

The scion is normally the same size or slightly thicker than the rootstock, particularly if the rootstock is used to inhibit the growth of the scion variety, as the picture shows. A quick pause here to elaborate on that last sentence. We have all either tried or been tempted to try growing a fruit tree from a seed we've found in fruit we've been eating. If you have ever been successful, one thing that would be immediately noticeable would be the size and vigour of the tree. In their natural state, most if not all our popular fruit crops can rapidly reach staggering sized plants. The problem with this is that you need a very large area to grow just one tree and you need a very long ladder to reach the fruit!Secondly, Apples for example do not come true from see. This means the pips produced from one fruit will not grow to produce the same fruit as the parent from which that original pip came. It is the same as human genetics. A child from any parents will never be an exact clone of either parent. As such, all Apple stock has to be increased by vegetative propagation. By taking cuttings, grafting or division.  Every specimen of Granny Smith or Bramley is in fact a slice from the original seedling. Only one of each variety has been grown from a seed. That is the plant that first produced the apple which some gardener thought was good enough to share and reproduce.
Some species are grafted to produce taller trees for ease of cultivation as the species in nature may grow as a low spreading bush making harvest and disease control a problem.
Roses tend to be grown on rootstock because it allows a faster production of commercial varieties and also allows for less hardy varieties to flourish in colder areas. In many instances, climbing or rambling roses for example, the natural growth on their own roots is far too aggressive for garden use.
Anyway, back to the tree planting. A well fed and well turned over soil is always going to be beneficial so I chose a spot that has some history. I originally prepared a mound of well rotted manure and compost and covered it in a layer of down facing turves so I could try growing a Melon plant three years ago. Sadly slugs cut through the stem when the plant was quite young so the heap remained for the next two years, growing only grass and weeds. This autumn I removed the top grass and sieved the soil for weed roots. A month later it's rich and full of potential. A quick tickle with a fork to open up the soil and after picking out any remain weed evidence, a good sized hole was dug and in went the rootball.
I used a bamboo cane laid across the soil to make sure the depth was right. There should be some evidence of soil on the tree showing the depth the tree has been growing at the nursery an this is the depth at which you should continue to grow you tree. It is common advice that we must support all newly planted trees with stakes and ties but I am rebelling against that as the specimen is quite short and previous fruit trees on the same site have survived well despite the lack of staking. I am also of the camp that believes allowing a tree to bend with the wind creates a thicker and stronger trunk with more likelihood of survival.
Once planted and firmed with the heel, the new addition to the allotment was given a good drink of fresh water to wash soil deep into the gaps between the roots. I won't expect any fruit in the first year, in fact I will be removing any fruit that forms as soon as the flowers fall. Producing fruit takes a lot of energy and that isn't good for a plant that is still settling in and putting out roots. I'll allow the energy to go towards establishing the tree first then allow fruit to come in the following year. Luckily Pears are long lived fruit trees and produce much better and more prolifically as they age.
I just know I can look forward to many years of fresh juicy Pears in the future!

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