Why choose Bitter Orange (Sour Orange)?
Technical analysis
Used for centuries, the bitter orange is perfectly suited to the difficult soils of southern regions: poor, stony, very calcareous and dry soils. It is extremely robust and gives the fruit exceptional flavor quality. It is moderately cold-hardy, down to 14°F (−10°C).
Point of caution
Its Achilles’ heel is the Tristeza virus. If this virus is present in your region, the tree can die suddenly. This is why it is used less and less in commercial production.
Quick comparison
The most tolerant of calcareous soils on this list (unbeatable on this point).
More cold-sensitive than the Poncirus hybrids: 14°F (−10°C) vs. 5°F (−15°C).
Riskier (health-wise) because of its sensitivity to viruses.
Our conclusion
The bitter orange is the "high-risk Great Classic." It remains irreplaceable for certain very calcareous soils where nothing else grows, but it calls for health vigilance.