Diverse Results with Metasequoia glyptostroboides
About 12 years ago I purchased 25 individually potted dawn redwood seedlings from Musser Forests, a bulk provider, thinking to plant an allay of trees along my very long driveway in Pennsylvania. They had a caliper of approximately 1/8", perhaps 8" to 10 " tall, and I planted them 25' apart. I planted all but 4, which I brought back to my other home in Brooklyn to "heel-in" over the winter. My Brooklyn back yard measures about 20 feet wide and 36 feet deep, a postage stamp really!
I got very busy for the next four years working on a gut/ rehab of the Brooklyn property. I was the designer, general contractor, head carpenter, and electrican in the renovation of a house built in 1847. My gardens in both places suffered as a result of my exhaustion and inattention. I just did not have the time or energy to devote to gardening duties. In Pennsylvania, the result was an overgrown tangle of specimens that I had initially placed too close together. In Brooklyn, the redwoods burst their tiny pots and sent roots deep into the soil.
The Pennsylvania dawns were mostly healthy, but there were some losses due to deer and rodent predation, Allegheny mound ants, and the annual August/September dry spell that really qualifies each year as a mini-drought. They made very slow progress, and now stand about 3 1/2 feet tall with a 3/4" caliper.
The Brooklyn four shot up like rockets, in a rear yard area enclosed by buildings that provided a protected, continuously damp environment, with soil too rich by half in organic material, but with a healthy daily dose of sunshine. These trees, too, suffered from my overwhelming work load, and remained where I had "temporarily" heeled them in. Two were crowded out and died, The remaining two, trunks touching at the base, have grown to 40' tall, with a trunk diameter at ground level of 15" Much to my surprise, these trees coned for the first time in 2014! I had read that dawn redwoods did not mature until they were 35 years old. It seems to me that acquired growth and size, and not the actual age of the trees is what fosters sexual maturity. Assuming that the original saplings were perhaps two years old, these trees are 14 years of age.
The Brooklyn back yard is a jumble, containing, in addition to the two redwoods, a monkey puzzle tree, a blue atlas cedar, and an additional assortment of conifers and deciduous trees, some planted by the former owner, and some by me. This tiny space supports a number of specimens that are quite large, as well as dwarf plantings, flowering annuals, and usually a couple of tomato plants.