Q: A friend gave me some nuts from the endangered mossy cup oak. I would like to know how to start these trees and take care of them. I have access to more nuts from this tree and am interested in planted several trees.
A: The mossy cup oak, aka bur oak (Quercus macrocarpa) is a lovely tree and is finally beginning to attract the attention of landscapers. Thankfully, I have found no evidence that the tree is threatened or endangered.
Germinating and growing the bur oak in Georgia may prove to be a bit tricky. Here is germination information from the University of Connecticut:
Acorns of bur (Quercus macrocarpa) oaks can be planted in the fall or stratified seed can be sown in spring. Stratify the seed at a temperature of 32 to 41̊F. Acorns of the bur oak require 30 to 60 days.
To stratify the seeds, you will need to put them in moist sphagnum moss and place them in a plastic bag in the refrigerator for 30 to 60 days. Make sure that they stay barely moist, but not wet.
Take them out after this time and plant 1 inch deep in a sunny spot that stays slightly moist.
Once they have germinated and reached about 8-12 inches tall, they can be planted in the garden. They prefer an organic, well-drained soil in full sun. Here’s the tricky part: bur oaks do not like acidic soil, which of course is common in Georgia. You will need to provide an annual application of up to 10 pounds of lime near the tree’s drip line for healthy growth.