pete_tree_smAt Suffolk Fruit and Trees, we receive many requests about tree size, and how it can be controlled. Tree size is also an important factor when choosing trees to plant in a mini-orchard, a garden, or in a pot on the patio. On this page we provide some general background information on tree size, and some guidance on choosing the right type of tree in your “orchard pack.”

Please note that the tree heights described below are given only as general guidelines. The final tree height depends greatly on depth of soil, site, and quality of soil.

If you have legal height restrictions (position alongside fence between neighbouring properties, allotment…), click here to read more.

It is mistaken to think that tree size can be controlled by pruning. The fundamental factors involved in determining tree size are the rootstock and the depth of the soil. Most fruit trees consist of two parts. The first is the “rootstock” or “stock,” which comprises the root system and the lower part of the stem, normally from soil level (the so-called “nursery mark”) to about 15 cm above the ground. The second is the “scion” which comprises the rest of the stem and the branches, and so it is this part that bears the fruit. Trees are created by grafting a tree variety – say Cox apple or Victoria plum – onto a rootstock, usually when scion and rootstock have a stem diameter of 8-10 mm.

This system is adopted to control the size of the tree and to improve cropping. So, for example, for apples, the rootstock named MM106 gives rise to a tree reaching a height of about 10 feet, while M26, M9 and M27 produce progressively smaller trees. M27 and M9 are therefore known as “dwarfing rootstocks,” and in a garden situation, they generally lead to disappointment. For most varieties, M26 is the most useful rootstock. The effect of rootstock is very marked on apples, less so on plums and pears. Another fact to remember is that the size of a tree at the time of planting does not affect the size eventually achieved. Likewise, the height of the tree at the time of planting has no effect on when the tree comes into production.

Other factors are involved in determining the height of a tree at maturity. These include type of soil, height of the location above sea level, exposure to cold winds or frost pockets, and the winter rest level of water in the soil. Equally important is tree spacing. The further trees are spaced apart, the greater their final height will be.
To help you planning your mini-orchard, here are some recommended planting distances, with a very approximate guide figure for final tree height (say 5 years after planting), for different fruit varieties:

Important: please note that we do not recommend the use of M27 and M9 for apples for the average garden situation. Scroll down for more information. In addition, the figures below are provided only as approximate guidelines. Final tree size will always be affected by depth of soil, site, and quality of soil.

Average tree heights obtained in garden/allotment situations

Apples
Rootstock Planting distance Final tree height Size description
MM106 10-12 feet 12-14 feet medium
M26 5-7 feet 8-10 feet
M9 4-6 feet 7-8 feet small – not recommended
M27 3-4 feet 5 feet small – not recommended
Pears
Rootstock Planting distance Final tree height Size description
Quince A 8-12 feet 12-14 feet medium
Plums, greengages
Rootstock Planting distance Final tree height Size description
St. Julien A 8-10 feet 12 feet medium
Pixie 7-9 feet 10 feet medium
Cherries
Rootstock Planting distance Final tree height Size description
Colt 8-10 feet 10-12 feet medium
Gisela 5 5-7 feet 6-8 feet medium-small
Peach, apricot, nectarine
Rootstock Planting distance Final tree height Size description
St.Julien A 10-12 feet 10 feet medium

 

You may ask, why can’t we be specific about planting distance? Why 8-12 feet and not, say, 10 feet? This is due to the many factors involved. Apart from the rootstock used, the variety of fruit, the depth of the soil, the available light and moisture throughout the growing season, all will influence the crop load and therefore the size of the tree. A heavy cropping tree will put on less new growth (extension growth) compared with a light-cropping tree. As an example of variety difference, Bramley’s Seedling makes a larger tree than, say, James Grieve. Trees grown on deep, water-retentive soil become larger than trees on drier or shallow soils. Trees grown in the shade crop less, and so tend to get larger than trees growing in sunshine. Fruit trees which go short of moisture during the summer months stop growing earlier each year, and will make shorter shoot extension growth. Fruit trees which are poorly pollinated will produce less fruit and therefore the annual extension growth will be much greater.

Finally there is the influence of the tree’s overall health, the site, microclimate, grass, weeds around the tree, depth of planting, nutrition, type of pruning, and the season in which pruning is performed. In fact, late summer pruning (in late July and August) tends to reduce the rate at which a tree will grow, whereas traditional winter pruning (November-March) produces strong regrowth of long new shoots.

So it’s a complicated equation, but it is one for which we are always available to give guidance and advice when you are ordering your orchard pack. Whether you’re looking for small fruit trees for sale or you would like to buy larger trees – just contact us.

One rule of thumb that always applies is: if you have room, give the trees as much space as possible, so at the top end of the space range as detailed above. This gives them the chance to develop a fine tree canopy.

Rootstocks for apples in a garden orchard

Let’s return to apples for a moment, because this is the fruit for which there are most rootstocks. While M26 is ideally suited for the garden, we can safely say that MM106 is by far the best and most robust stock for a mini-orchard. In addition, MM106 is suitable for all soils.

We don’t recommend the use of rootstocks M27 and M9 for several reasons. Firstly, for the average garden, M27 and M9 create a root system that is too weak to keep the tree upright in later years, when it is in full production. Secondly, the correct type of stakes necessary to stop the trees from blowing over are often unobtainable in garden centres. Third, M27 and M9 trees tend to over-produce fruit in one year, with no, or very little, fruit the following year. Lastly, the bark of M27 and M9 apple trees are the most appetizing to mice, rabbits, hare and deer, which nibble the bark in winter, leaving sick trees with too small fruit.

Based on many years of experience we strongly recommend using MM106 rootstock if space is not a limiting factor. If the available room is restricted, then for dwarf sized trees we recommend planting fruit trees on rootstock M26

For successful apple tree growing, MM106 is the best choice. It has proved itself over many years; it forms a healthy tree which fruits at a young age. MM106 is suitable for all soils, including heavy clay soils, provided the soil is not waterlogged.

rootstocks

Contact us: enquiries@realenglishfruit.co.uk

Phone 01379 870759