Apple Rootstock Selector by Soil Texture & Stature
Match apple rootstocks (M.9, M.26, MM.111, G.41, G.890) to native soil drainage, fire blight risk, and canopy height.
Enter botanical and planning parameters
Biological Mechanism & Horticultural Rules
Rootstock selection dictates tree size, precocity, anchorage, and disease resistance. Malling rootstocks (M.9, M.26) are highly susceptible to Fire Blight and Phytophthora. Geneva series rootstocks (G.41, G.890, G.935) bred by Cornell/USDA provide documented genetic resistance to fire blight and Phytophthora collar rot, but no rootstock can compensate for prolonged waterlogging or anaerobic standing water. On heavy, poorly drained clay soils, improve drainage or plant on raised mounds/berms (12–18 inches).
Final mature tree height is an approximate range that varies with scion cultivar vigor, soil fertility, and summer pruning.
Frequently Asked Questions
Why does M.9 rootstock require permanent staking?
M.9 produces brittle root tissue with a high bark-to-wood ratio and lacks deep taproots. Without a post or trellis wire, crop weight and wind will snap the tree at ground level.