M27 is not readily available around Australia and is really only for very small trees, this is far to small to multi graft, it may prove useful for stepovers . (We don’t sell or use this rootstock) be careful of anyone putting multi vars on this tree as it will struggle live let alone set fruit, I would use it for the fancy Stepovers, but they are lots of work
M9 is a very useful one for backyards and is used extensively for close orchard plantings (fitting 6000 trees per acre) wires are used to support the tree in windy conditions as it has a weaker, brittle root system , this is not a problem in back yards and it is the best one for growing an apple in a pot. It also tricks trees into fruiting very quickly (even in just 2years) it be prone to wooly aphid. We have 2 rows of trees on this rootstock that have good size fruit and have not needed any pruning in 15 years, one has produced ave 55kgs of apples each year with no additional watering, just a good straw mulching
USE– Pots, small backyard tree, Height 1.8m plant spacing 0.6-2m
M26 a very versatile tree size for back yards it can be a nice size single tree shape or can be a smaller espalier (2m wide) if space is limited or you want to squeeze more vars into the back fence.
We find this one of the most useful sizes, easy to net and produces fruit 2-3yrs with good anchorage and enough vigor to produce very pretty tree shapes, we will use this one with our next 400 vars being planted in the collection
USE– small tree, small espalier, can multi graft, Height 2m, spacing 1-2m
( NB: we have been told M26 does not seem to like grafting Triploid vars, but this has proven wrong here with us, we have found one supplier of rootstocks was the issue, 91% of their rootocks died in pots waiting to be grafted due to poor root developement )
MM102 this one is a Northern Spy clone but only half the size, it makes and ideal orchard tree for a larger backyard and is very good for espaliers, suitable for multi grafting you could have all your apple needs on this one tree in the backyard. Not shown in table, between P1 & M7
Uses: semi dwarf tree, espaliers. Height 2.7-3.0m Space 1.8-2.4m
MM106 is a good size small orchard tree or for a bigger espalier and large backyards, it gives good vigor and heavy crops. Also ideal if you want to prune to standard trees out of reach of small farm animals.
USE– large backyard, orchards, Height 3.0-3.6m plant spacing 1.8-3.0m
MM111 a larger tree size that is very suitable to harsh soil types such as around the goldfields area, it also has some resistant to Fireblight and may need to be used in commercial orchards in future.
USE– small to large orchard on poor & dry soils, can multi graft, Height 3.6-4.2m, spacing 2.4-4.5 m
Northern Spy is a traditional old orchard tree rootstock with good production in Victorias apple growing regions it’s planted at 5 mtr x 7 mtrs spacings and grows to 5mtrs, we only use it for cider trees now.
M793 is a vigorous rootstocks suitable for orchard situations,
Uses: Orchards Height 4.0-4.5m Space 3.6- 4m