This cloud forest Mexico oak is rarely encountered in the USA. It is native to East and N.E. Mexico, usually found at 800-1800 m. (2625-5905 ft.). The species reaches 25 m. (82 ft.) tall, but should be smaller in cultivation. We have two Royal oaks over ten years old and have been distributing acorns to interested nurserymen.
Leaves are lustrous, green, and glabrous, 9-13 cm. (3.5-5.1 in.) long and 3-5 cm. (1.2-2.0 in.) wide. Leaves are persistent or semi-evergreen, oblong to oboval or oblanceolate. Acorns are large and can be up to 4-5 cm. (1.6-2.0 in.) long and 2-3 cm. (.8-1.2 in.) wide, and single on a short peduncle. Prior to maturing, almost the entire nut is enclosed by a warty, pubescent cup. Two trees in the SFA Gardens have experienced winter freeze events less than -12oC (10oF) with only minor foliage damage. While wet mountainous forests describe the native habitat, the species appears quite heat and drought tolerant once well established.
Acorns germinate readily for us, quickly forming a vigorous tap root, before sending up a shoot. We have learned over the years that the young plants are very susceptible to overwatering. We suspect the tree will be hardy in Zones 8 and 9, and deserve testing in colder zones as well.
It is best to harvest acorns while they are still attached to the trees as weevils infest acorns on the ground quickly. The acorn above not ready. We have also observed vivipary (germination while still attached to the tree). Acorns should be harvested from tree, not from ground. Weevils are quick in Texas. We recommend that they be sown in the fall and the emerging seedling should be protected from freezing temperatures that first winter. The young seedlings must be grown on the dry side and are prone to damping off if overwatered.
In a well drained mix, a 5 gallon flushing some new Fall growth, 2016
Acorns are perfect chunking size.