There may be more individually named cultivars of the Hinoki Cypress (Chamaecyparis obtusa) than any other conifer. I have seen thousands of seedlings, and a multitude of mutations within this species over the years. Most of which were being evaluated for unique characteristics, resistance to pests, hardiness and overall aesthetics. Of course many other horticulturists have done the same over the years, and hundreds of cultivars have been named and distributed either through collectors or the commercial marketplace.
Back in the early 1980s, a group of very mature Chamaecyparis obtusa ‘Nana Gracilis’ at Iseli Nursery produced a proliferation of viable seed. Thousands and thousands of seeds were planted, many of which germinated and the evaluation process began. The gene pool was vast that contributed to the pollination of the tiny cones that produced all of those seeds. Iseli Nursery had an extensive collection of mature cultivars which contributed to that pollination process. As a result, a very wide assortment of characteristics became visible rather quickly in the evaluation process. Some seedlings grew very quickly and appeared very much like the species, Chamaecyparis obtusa. Some were more vigorous, some less. The slower growing seedlings were given great consideration – as were those with unusual coloration or different foliage types. Eventually those plants that were considered to have the least chance of commercial appeal were culled and the remaining plants were planted in the ground, sorted by growth rate, foliage type and foliage color.
Many years went by with regular evaluation. Some of these seedlings began to show great promise. Extremely slow growth rates, unusually dark green foliage, bright yellow foliage, fine textured foliage, sculptural growth forms – whatever made an individual plant stand out from the crowd and appear different than other known cultivars already named, either in collections or being marketed. Some of those seedlings were then selected and the propagation process began, spanning 15 to 20 years in the process. Some of those exciting new plants have started to become available to garden consumers through independent garden centers over the past few years.
Perhaps you have seen, ‘Just Dandy’ or ‘Jane’s Jewel’. One of my very favorite plants ever just happens to have originated in that very same batch of seedlings, all those years ago. Chamaecyparis obtusa ‘Gemstone’ is truly a treasure.
‘Gemstone’ is a very slow growing Hinoki Cypress with a narrow, upright form. When young, it reminds me of a small, pointed wizard’s hat. As it matures, occasional side branches will develop adding aesthetic interest to the already pleasing, casual movement to its upward growing form. The largest plant I have seen is in the Jean Iseli Memorial Garden and is pictured above. This specimen is one of the early propagations off of the original mother tree which is growing in an undisclosed, secret location.
I absolutely love this cute little dwarf conifer!