Why choose Citrumelo 4475?
Technical analysis
Citrumelo 4475 is an extremely vigorous rootstock that acts as a true engine for the scion, promoting early bearing and substantial canopy development. While it is exceptionally resistant to root diseases such as Phytophthora and tolerates temporary wetness well, it thrives primarily in deep, free-draining soils (sands, silts). Unlike Poncirus trifoliata, its roots have a vital need for oxygen and can suffocate in clay that is too compact and sticky in winter. Climatically, it induces enough dormancy to withstand freezes down to 5°F (−15°C), but it remains a strictly calcifuge plant: the presence of active limestone triggers a sudden iron chlorosis that stops its growth dead.
Point of caution
In calcareous soil (pH > 7), it triggers a sudden chlorosis that stops the tree’s growth dead.
Quick comparison
Our conclusion
The Citrumelo is the "free-draining soil specialist." It is the number one choice for acidic, sandy soils where its vigor will work wonders, but it should be avoided if your soil is a sticky, calcareous clay.