Redwoods have grown successfully in the Otways and Strzeleckis in Victoria. There's one growing on the block next door that's so big in diameter I think it might be a giganteum. And it's on an exposed site next to a house although it may have been more sheltered when younger. A few weeks ago I was on a field visit to the Lardner Agroforestry demonstration site in West Gippsland not all that far from us. They have a small grove of redwoods planted at only a few metres separation 13 years ago in a damp spot. Some are already ~40cm DBHOB. A lot of this diameter would be bark but it's still an excellent growth rate. Our block has better rainfall and possibly better soil.
We have some sites on our block that I think might be well suited to growing redwoods but I'd be grateful for any pointers from people who have successfully grown them in former pasture. Some sites on our block are south facing (we're southern hemisphere so this is cooler) and the others are in creek flats on the south site of the creek so exposed to summer sun from the north.
There are drainways coming down the slope so while these aren't permanent watercourses they are wet during winter and stay damp during summer. Obviously we would weed/pasture control at planting. We could probably get away with planting them fairly close together with edge effect of the roots spreading out into the surrounding pasture. They would make a nice windbreak from the westerlies and if they can achieve similar growth rates would be harvestable in a lifetime. Or just thin a few and sit back to watch them grow on to serious height!
How will they go being planted into a site with plenty of water (generally well over 1000mm/annum with some summer rainfall) but with exposure to occasional 40C days in summer? And some wind in winter at least to start off with.
And are they OK with having their feet wet in water logged soil during winter? Or would they do better planted slightly out of the drainways?
We could also plant Western Red Cedar in these spots but again I wonder if they won't be happy with the direct exposure to summer sun that's hotter than their native range.
When's the best time to plant a tree? About 20 years ago. When's the next best time? Today!
I think you'll find that the fungi to bacteria ratio that redwoods prefer is in the 100:1 to 1000:1 range. You could check what you have in yourpasture and maybe do some fungal enhancing if it's not near that. They'll grow before it gets to that ratio, and the trees will move the ratio towards that, but you'll be off to a better start if you can get the fungi in the soil for the trees. This will also give you some ideas what will go well beneath them, maybe strawberries, raspberries, apples, and stone fruits.
About "western Red Cedar" I can be of no help as in the US there are several plants that go by this name. The one in my region is actually a juniper and is adapted to dry conditions. The one in the pacific northwest is botanically not a cedar, and there is incense cedar, one of my favorite trees. Here is a link for incense cedar, which might be fine for your north facing slopes http://www.nwplants.com/business/catalog/cal_dec.html
About the redwoods, I lived in the redwood forests of northern california for a few years when I was a teenager. They grow with their roots on or in the banks of small streams. When flooding changes the level of the soil, they grow new roots where gravel has buried several feet of their trunks. When I think of the flood cycles in the thousands of years they have lived there, I feel pretty certain that once established they can stand wet feet in the winter just fine. I also think they would survive the occasional very warm day in the summer.
One thing about redwoods, a single one left standing alone when all the others are harvest can get blown over. It is better to plant them in groves or groups where they provide some protection for one another. And when harvesting, to leave groups of them. I think they also will send up new trunks from established roots.
Best luck: satisfaction
Greatest curse, greed
Location: Grand Valley of Colorado's Western Slope
posted 3 years ago
And one more thing I forgot. They send up new trunks that can become ancient trees from stumps of cut or fallen trees.
I hope you will plant many and they grow and thrive there.