I grew 15 giant red woods from 20 or so seeds after collecting a red wood cone at Warwick castle in 1995.
To germinate them I stratified them in the fride for three months and then raised them in a simple box up with a thermostatically controlled home made plant raiser with a 50 watt light bulb as the heat source & a Perspex sheet for the lid .
Each seed was in it's own 3 inch plant pot sown at about 1/2 deep and set on its edge like you do with marrow seeds etc. Don't ask me why ..it seemd reasonable to say .." Flat seed so sow it on its edge " .
This box used to sit in the potting shed near the window but out of direct sunlight , can't remember how long it took to germinate
Perhaps look it up on the " RHS " website they will ( used to ) give FOC a lot of info on growing almost any kind of seed or propagation method etc .
I was using a trigger spray pack every morning with a baby bio solution to keep them ever so slightly damp , Any condensation was wiped off the Perspex each morning and on really warm days I lifted the Perspex up on clothes pegs to give some much need ventilation .
to the contents .
Potted them up at about three inches tall and then re-potted ghem several times till they were over wintered in 4 gallon plastic buckets with several crocked up drain holes in each bucket . Using John Innes potting mix and left on the north side of a wall for over wintering but slightly protected for the icy North winds by hedges .
They were set in place the following March in a 2 foot x 2 foot hole, half filled with quality well composted manures and mixed in with JI's potting mix till the hole was able to take the bucket ( pack soil around the bucket to give you the correct size hole you will be transferring into them , knock the bucket sides and careful slip the contents out on to a pair of hands , then invert it and gently put it in the hole .. gently water in with a couple of buckets of rainwater & some basic tom fed .
I grew them to about 800 mm tall at 50 mtrs apart and set them up as boundary markers . Enclosing them in pig wire so it stood out above any weeds or grasses that might grow and an inner wall of 1/2 chicken wire to keep the rabbits & hares off them & whacking in a treated 7 foot x 4 inch post as the boundary marker .
It was easy to take a trip on the big ride on mower c/w sweeper /collector to keep the area weed free and then fairly easy to de weed the pens. ..in the end I kept putting cut shapes of thick walled brown cardboard around the bases of the redwoods to suppress the weeds & gave a sprinkle of slug pellets around the wire edges to stop the slugs having breeding holidays under the cardboard .
Each sapling had to be given a bucket of water at least once a week from March till the end of September or the middle of October as that is the driest time of the year there .
I added some first stage liquid tomato feed to the water on all occasions as the " soil " there was imported inert construction stuff that had been put through a 10 mm grading screen system to remove all steel re bar & larger rubble /concrete lumps
The biggest problem was keeping the enclosures weed free so as not to choke the saplings . After three years they were about 1000 mm tall and starting to complete well with the taller weeds like sow thistles , burdocks & the tall Scottish thistles
I sold the property at that point , the new owner was quite different to me . Apparently he kept spraying everything in agricultural grade Round Up & killed the lot. Then he put up a sheep fence and sprayed 2 mtrs either side of it three times a year so he could let his St Bernard's run loose on his " new fully enclosed puppy farm " .