Seed storage and pretreatment for Sequoia sempervirens

Common name	Redwood (Coastal) or Coast redwood
Scientific name	Sequoia sempervirens
Storage characteristics	Intermediate (?)^a
Storage moisture content and temperature	9-12% @ < -5°C^a
Dormancy characteristics	Shallow
Pretreatment method	6 (3-9) weeks cold (c. 4°C) See pretreatment of shallowly dormant species
Efficacy of pretreatment / remarks	Generally effective, a significant proportion of live seeds should germinate
Approximate date to initiate artificial pre-treatment (for 1 March sowing)	18 January

Footnotes

Storage characteristics

Intermediate - seeds that can only be partially dried or need very slow, careful drying. They deteriorate more quickly than 'orthodox' seeds but more slowly then 'recalcitrant' seeds.

Orthodox - seeds that can be dried without harm, and once dried can be frozen, stored for years with little deterioration and relatively easily revived.

Recalcitrant - seeds that cannot be dried or frozen and are therefore short-lived.

(?) - indicates storage characteristics are not yet fully understood.

^a Maximum advisable storage c. 3years @ c. 10% moisture content & -10°C

Pre-treatment method

Figures in brackets indicate that different seedlots often require different pretreatment durations. There are three potential courses of action:

Adhere to the pretreatment duration in bold, with the knowledge that the maximum potential germination of the seedlot may be sacrificed for the sake of simplicity.
Inspect the pretreating seed regularly. Sow when c. 10% of seed is chitted, with the hope that this is indicative that the remaining seeds are now close to germination.
Inspect the pretreating seed regularly. At suitable intervals, remove chitted seeds (by hand, flotation, and/or sieving). Sow chitted seeds and return balance to pretreatment until no more seeds germinate.

Practice Guide

Cover Raising Trees and Shrubs from Seed ^(PDF-648K)

Forestry Commission Practice Guide 18.

| | | |