I have a Coastal Redwood that I have been working on reducing the roots on for about two years now. That is one of the reasons for my post concerning advanced root pruning. This tree is 40 inches tall and was sold at Wal Mart as a 'living Christmas tree'. I cut about 1/2 the bottom of the root ball off because it was severely root bound in the pot it was in, then I put it into a large pot with very coarse soil and let it grow for a year. Then I did the same thing the next year and have the roots down to a shallower pad but they are all fine fibrous roots with hardly any visible root flare. I haven't even begun to start styling the tree yet but I have a couple possible ideas once I get the roots down to where I can plant it into a shallow growing box. I keep mine outside year round on the southeast side of my house where it gets morning sun and is protected from the scorching afternoon sun of summers. It is healthy and thriving but I wouldn't recommend it being moved indoors.

Most trees and shrubs important in nurseries will grow in bark and sand. The common method is a coarse and clean mix like this regularly and liberally watered, and kept well fertilized. A friend produces redwoods for commercial sales using this method. Two different commercial grower-oriented slow release fertilizers are incorporated at the time the mix is prepared (he makes his own potting medium). When I worked on a small rhododendron and azalea farm many years ago the evergreen azaleas were being potted in pure bark mulch. The old man would come out of the house each afternoon and hand water these with a wand connected to a fertilizer injector, so the bark was being fertilized every time it was watered.

" I wonder how one would do in pure muck soil where taxodium grow, if inland enough where saltwater flooding isn't a problem." Not well! It would last about a week in summer before the root rots would take it out! In the rest of the southeast where they do grow, they definitely only grow on well drained soils. I have had one die from root rot. In spite of being hexaploid, they are not invincible. FWIW, there's a 'trick' about the PNW - coastal CA climate. I saw rhododendrons almost in the bottom of swales at the old Greer Gardens in Eugene, OR.* You would NEVER see them growing somewhere like that in PA, NJ, or MD. But...the time plants like rhodies and redwood are most susceptible to root rot organisms is in the summer. That's when most of those disease organisms grow best...at temps >= 15C. I see redwoods in the native environs growing in soil that appears year round damp, but guess what? It's only going to be inundated with water, during California's wet winters! Likewise with the rhodies that would experience wet (but not underwater, mind you) soil conditions at Greer...only in winter! There's just NO WAY for Eugene to have 3" of hot wet rain in late July, on a single day, as we can have! (or, now that I think about it, at Sonoma Horticultural Nursery, which is called something else these days, the same is true. Although Polo did put some rhodies on the lowest plains of his property in impromptu little raised beds. That might be necessary because he was so mild in winter, root rot organisms could still grow well during the wet season.) Now that a nursery has supposedly grafted Sequoia onto Metasequoia, maybe people in the southeast can plant them in poorly drained soils with abandon. We'll see. * - although, TBH, it wasn't much to see and not even as nice as the peak of NJ Rarefind around the time Hank died in 2009, I'm glad I got to see it in 2011 and meet the famous Mr. Greer. Greer might have had rarer, more tender cultivars in zone 8a, but Rarefind had just more plants, and better displayed, period, in their 6b garden.

Yep, low in initial fertility is the key. Obviously you don't want to burn or inhibit growth, but a light charge of nutrients should be available once the plant/cutting can effectively make use of the nutrients. I almost always include some Osmocote in my mix for that very reason: the nutrients won't be heavy up front, but they'll be there when the plant needs it. I wait approximately two weeks to begin fertigation after re-potting a rooted plant, as well. This phase of low initial fertility apparently helps with the re-establishment of roots in a new volume of soil/mix. Josh