One of the wonderful aspects of growing fruit trees is the huge variety of each fruit type available. This is especially true of apples. But, even more variety is possible through the selection of different rootstocks on which varieties are grafted.
We have selected three rootstocks to provide a good range of options for home gardeners and orchardists alike.
M.9 : Height* to around 2 metres, trees produce fruit within 2 years. Trees need staking or trellis support.
M.26 : Height* to around 2.5 metres, early producer. Ideal for espalier or trellis.
MM.102 : Height* to around to 3+ metres, early producer, staking not required.
Big is not necessarily Best!
Beginning in 1912 The East Malling Research Institute in England selected and began trials of a range of rootstock material. Clones included ranged from those with a very dwarfing influence through to those with an invigorating influence on the cultivar. One of the interesting features of dwarfing rootstocks is that the dwarfing influence does not extend to the fruit. In fact fruit on younger trees is often larger.
The resulting Malling series, identified by the letter M followed by a number have gone on to play a major role in commercial apple growing throughout the world.
In 1928 work began on another equally important series of rootstocks when the East Malling Research Institute together with the John Innes Horticultural Institute began a program to produce woolly aphid resistant material, an attribute not found in the Malling selections. The resulting trees were named the Malling Merton series (denoted by MM and a number).
Some practical 'modern' benefits of clonal dwarfing rootstocks
Dwarf trees need less water in a dry climate, less fertiliser in a world of scarcity, take up less space in a smaller yard, have a lighter impact on surrounding plants, are easier to protect with netting, are safer to maintain and pick, produce more fruit per square metre (trials show nearly 50 tonne per ha is achievable, ie 5kg per square metre!), produce fruit much quicker than seedling rootstocks and allow more varieties to be planted in a given space.
Malling 9 (M.9, 'Jaune de Metz')
A chance seedling found in France in 1879, this is one of the most widely used dwarfing rootstocks in use today with many commercial orchards changing their entire plantings to it. It is used to produce small, compact trees for the home garden and for high-density commercial plantings (which can reach 4000 trees per ha).
Adaptable to a wide range of soil types, but is reported to be unsuitable for dry, sandy soils. It can tolerate a heavier soil type and wetter soil conditions. It is susceptible to Woolly Aphid.
Malling 26 (M.26)
Introduced in 1959 it is a cross between 'Malling 9' and 'Malling 16'. Produces trees a little large than M.9 and a little sturdier, although, except in the most sheltered situations, some staking or support is recommended.
A semi-dwarfing or intermediate vigor rootstock, M.26 produces a tree that is larger than M.9, but smaller than MM.102. Somwhat susceptible to Woolly Aphid.
Malling Merton 102 (MM.102)
MM.102 is a cross between Northern Spy and M.1 produced by the East Malling Research Station. It produces a tree a little larger than M.26, but still compact. Fruit production is good and trees do not require staking. MM102 has resistance to woolly aphid.
*Plant growth is always influenced by climate, nutrition, water availability, etc,
so height figures are only a guide.
