Importance of choosing your rootstock
Here’s some helpful advice from Grow at Brogdale about rootstocks and how to select the best rootstock for your fruit tree. Choosing the correct rootstock is as important as choosing the right variety. Trees are very much like people, with varieties having differing amounts of natural vigour. Your soil will also be a deciding factor, with clay soils having a dwarfing effect on trees. Bramley for example is very vigorous whilst Decio, one of the oldest varieties in the collections is very dwarfing and will need all the encouragement we can give it to grow!
The history of rootstocks
Until the twentieth century here was very little choice when it came to rootstocks. If you wanted to plant an apple tree, most likely it was on a traditional orchard rootstock and it was going to be big! The first half of the twentieth century saw much investment and research into apple rootstocks at government research stations, East Malling and Merton.
These new rootstocks were recognised by their prefix M for Malling and MM for Malling- Merton. They remain the most popular rootstocks used today.
Choosing your rootstock
The temptation if you are wishing to grow fruit trees that are to be kept relatively small, is to simply plant dwarfing rootstocks. But if your soil is heavy, particularly clay based, this will further stunt the growth resulting in an unhappy tree, struggling to get through the heavy layers of clay. Our head nurseryman has a favourite saying “it will just stand there and look at you!” meaning it is unlikely to produce much fruit at all and will struggle to get all of the nutrients it needs from the earth by itself.
For smaller trees to be planted in pots etc, we would recommend you choose M27, M7 and M9 for apples, Gisela 5 or Gisela 6 (G5 & G6) for cherries, Quince C (QC) for pears and Pixy for stone fruits. Step-overs, cordons and patio trees will all be on dwarfing rootstocks.
To plant directly in the soil where a smaller tree is required, consider bushes or restricted forms such as espaliers and FANS.
Grafting larger trees
On the other hand, if you wish to plant larger trees, half-standards will probably be the most suitable for you. These tend to be grafted onto semi-vigorous rootstocks; MM106, MM111 and MM116 for apples, Quince A (QA) for Pears, SJA for stone fruits and Colt for Cherries.
Espaliers are also largely propagated onto MM106 as some vigour is required in order, for the tree to have enough oomph to continue to be able to put on the growth required to form the tiers.
If space is not an issue and you wish to replant old orchard style trees, look at full standards or trees grafted onto vigorous rootstocks. M25 for apples, Pyrus Communis and Seedling for Pears, Brompton and Myrobalan for stone fruits (seedling rootstock), Avium F12/1 for Cherries but a very tall ladder will be essential!