Handbook of Plant and Crop Physiology

98 CHONG ET AL.

TABLE 3

Continued

Pretreatment

Stratification (months)

Plant

Collection

Warm

Cold

Species

type

date

Storage

Scarification

(20–30

C)

(1–5

C)

Remarks

Ginkgo biloba

Maidenhair treeGinkgoaceae

Gleditsia triacanthos

HoneylocustFabaceae

Gymnocladus dioicus

Kentucky coffeetreeFabaceae

Halesia carolina

Carolina silverbellStyracaceae

Hamamelis virginiana

Witch-hazelHamamelidaceae

DT DT DT DS DS

Late fall Sept.–winterWinter Oct.–Nov. Aug.–Oct.

1 year if stored

moist

2 

years at0–5

C

5 

years dry

1–2 years dry at

0–5

C

1 

years at0–5

C

H

SO 2

4

1–2 hr or

hot water soak,leave overnight

H

SO 2

4

2–4 hr or

nick seed coatwith a file

1–2 (2) 6

following

first

prechilling

3

1–2 None None (1) 3

initially(3) 4–5

after warm

3

Collect fruits when dropped.

Remove seeds bymaceration in water beforestoring or sowing. Freshseeds will germinate but atlower percentage.

See note 5.Seeds are large.Very complex dormancy;

require (1) cold–(2)warm–(3) cold in thissequence, but outcome notdependable. Most reliablegermination is obtained byfall sowing outdoors.Germination will occurthe second spring.

See note 5.Collect capsules while still

yellowish and before opento avoid natural seeddispersal. Also, if fallsown early, germinatonmay occur the first spring.If seed is ripe and dry, asecond season will beneeded.

See note 5.