Growing Champaka in Virginia

Q: I purchased a Magnolia champaca 1 gallon a few years ago. It is still growing as I bring it into my greenhouse in the winter. I live in VA. This spring I planted it in the ground hoping it might bloom which it did not. Will it survive our fairly mild winters with several freezing days with some special attention? What would you do?

A: Magnolia champaca is a tropical tree and won't survive winter in VA. It can not take hard freeze. Your only option is, to keep it in a pot and bring inside. If the temperature inside your greenhouse is too low, this may affect the plant's ability to flower. For example, if it stays 35-40F for a whole month - although it is not a hard freeze and the plant may survive, but the duration of the cold period is more critical than the low temperature itself. Champaka can survive a few hours even at upper 20's, but not many days with cool temperatures. The temperature in winter should be maintained at least above 55F during day time (the higher the better) and at least above 45F at night.
If the tree has grown too big, you may trim it. If the root ball is too large, roots can be trimmed too (similar way like they do with bonsai) before repotting. However, trimming must be done either during warm season and active growth, or in Spring, when the tree starts waking up and promotes new growth.
To encourage flowering, start fertilizing your Champaka with a liquid bloom booster - SUNSHINE Pikake - Fragrant Flower Booster. It can be used year round including winter months, and it is safe to apply with every watering. This way you will provide to the tree enough energy for the next flowering season, so flowers can be expected in late Spring - Summer.

Read more about greenhouse growing: Greenhouse in Virginia.