Dormancy in Seeds

 Listed below are the dormancy requirements for some common Virginia trees. This information is essential to nurserymen who grow seedlings for replanting and reforestation. Most trees require prechilling or over-wintering before germinating. This is to simulate natural conditions. The process is known as stratification.

Tree	Seed collection dates	Special instructions	Dormancy
Sweet gum	Collect seed heads while they are still closed and on the tree.	Spread seed heads on a dry surface for 5-10 days or until they open. Shake to remove seeds.	Short- requires only 15-30 days of prechilling (5° C).
Loblolly pine	Collect ripe (green) cones before they open. (Sept.-Oct.)	Spread cones on a dry surface for 2-6 days or until they open. Shake to remove seeds.	Medium- must overwinter before germinating.
Red oaks (southern red, pin, willow and black oaks)	Collect acorns as soon as they drop from the tree. (Sept.-Oct.)	Discard all acorns with small holes (weevil damage).	Medium- must overwinter before germinating.
White oaks (white, basket, chestnut and post oaks)	Collect acorns as soon as they drop from the tree. (Sept.-Oct.)	Discard all acorns with small holes (weevil damage).	No dormancy- will germinate immediately.
Red and silver maple	Collect winged “helicopters” when they fall from the tree (April-June)	Seeds ripen August-October	Short- no prechilling required.
Sycamore	Collect anytime after seed heads turn brown. (Nov.-April)	Dry seed heads on trays until they break apart easily.	Medium- must overwinter before germinating.
Beech	Sweep burs from the ground after frost. (Oct.)	None.	Poorly understood.
Black cherry	Pick when fruits are ripe (black). (Aug.-Sept.)	Air dry seeds and store in plastic bags.	Long- one to three winters before germinating.
Black locust	Pick pods from tree from late August throughout winter.	Remove seeds from pods.	Seed coats are hard and must be scarified before germinating.
American elm	Sweep seeds from the ground. (March-June)	Air dry for a few days.	Medium- seeds must overwinter before germinating.
American holly	Pick when fruits are ripe (red). (March)	Remove seeds from the fruit by squeezing between your fingers.	Long- two to three years before germinating.
Hickory, pecan	Collect nuts as soon as they fall from the tree (Sept.-Dec.)	None.	Medium- nuts must overwinter before germinating.
Tulip tree (Yellow-poplar)	Seeds can be collected from the ground almost anytime.	Low germination (10%) because of poor flower pollination.	Medium- seeds must overwinter before germinating.
Dogwood	Pick ripe fruit (red) from the tree. (Oct.)	Spread on a dry surface	Long- one to two winters before germinating.