New Companion Plants: Classy Connecticut Conifers
L. Clarence Towe
Walhalla, South Carolina
Several individuals currently involved in developing and introducing new plants are doing so at a time when tissue culture can make their selections available relatively quickly. A few examples are Dr. David Leach (elepidote rhododendrons), Mr. Wayne Mezitt (lepidote rhododendrons), and Dr. Richard Jaynes (mountain laurels).
Though many conifers have to be grafted and are slow to get into the trade, several introductions developed from witches'-brooms by Dr. Sidney Waxman, a retired University of Connecticut professor of horticulture, are now available. Beginning over 30 years ago at the University of Connecticut (Storrs, Conn.), Dr. Waxman found that brooms in conifers were a source of compact seedlings. Some brooms produce fertile cones and a percentage of seedlings from these cones will be variably compact. Dr. Waxman began his research by collecting broom cones from several conifer species throughout New England. Many of the brooms he located himself, while word of others came to him as his interest in them became widely known.
Dr. Waxman's nursery.
Photo by L. Clarence Towe
After germinating the seeds in a greenhouse, they were then transplanted to the university nursery. In some cases as many as 700 seedlings were grown on from the cones of one broom. As the seedlings matured, the better ones were kept for evaluation while the remainder were sold to support his research.
According to Dr. Waxman, broom cones of most species of pines will yield a 1:1 ratio of normal to compact seedlings. In most instances, the compact seedlings can be spotted by the end of the second or third growing season, thus allowing the normal seedlings to be discarded or to be used as understocks for grafting. He also found that compact seedlings fall into six basic categories with regard to shape: mounded, conical, flat-topped, prostrate, weeping, and grotesque.
Typical pine witches'-broom.
Photo by L. Clarence Towe
As his compact selections matured, he noticed that some would occasionally produce cones with viable seeds themselves, thus allowing him to progress to the second generation. One of his most unusual selections to date is 'Low Grow', an F2 Japanese red pine, a well-behaved mound that every conifer lover should have. This is a unique plant that draws close attention to its form and texture, resembling a cross between a pine and a cactus - or perhaps a prickly toad waiting to be turned into Prince Charming.
A walk through Dr. Waxman's trial nursery is an almost surreal experience. Being surrounded by tall trees on all sides, a passerby would be unaware of the secrets that grow inside. Near the entrance is an "inverted" broom, guarding the grounds like a crouched gargoyle. Unlike most brooms which are located higher in the tree, this unusual one was given to him by a friend years ago and gives an eye-level view of the source of his work.
Compact seedlings of various species and seed lots are arranged in neat rows with labels to identify the seed source. Many holes are in evidence, the result of the removal of large specimens determined to be worthy of sale but not of introduction. As the evening shadows lengthen, the holes and rows of seedlings of various heights and shapes give the area a mystical look, perhaps of ancient Druids having arisen from shallow graves for worship around a coniferous Stonehenge.
Near Dr. Waxman's office at the university is a dramatic European larch with strong, primary limbs pointing upward in many directions from the trunk, hence his appropriate name of 'Varied Directions'. With the secondary limbs weeping to the ground, the tree bears a striking resemblance to the Phantom of the Opera or Dracula robed in a flowing green cloak.
Off Dr. Waxman's rear deck at his home in Storrs, a long limb from a nearby white pine droops within arm's reach. At the end of the limb is a small broom. Dr. Waxman denies having grafted it there, but the twinkle in his eye (or is it a glint?) suggests otherwise. His wife, Florence, wisely avoids the issue. If a leading authority on brooms coincidentally has a broom in his back yard, he surely has access to powers not available to us!
As with most things, his selections must be seen to be appreciated. In addition to compact conifers, he has also worked extensively with Sciadopitys erticillata , Japanese umbrella pine, and has made two selections in this species. Now retired and busy with his nursery, Dr. Waxman continues his work and more releases are on the way. He has not yet named a selection after himself, though to those who know him, Pinus strobus 'Soft Touch' is synonymous with Sidney Waxman.
Waxman Nursery Releases
The following is a partial list of Dr. Waxman's releases. Unless otherwise noted, dimensions are for plants approximately 10 years of age. Many of the plants are available from nurseries advertising in the ARS Journal.
1. Larix laricina (eastern larch) 'Newport Beauty' is an extremely compact selection, 15" high x 30" wide with branches reaching to the ground.
2. L. laricina 'Deborah Waxman' is a dense, upright selection, 5' high x 3' wide with vertically oriented branches.
3. L. decidua (European larch) 'Varied Directions' is a relatively fast growing selection with branches that reach out in various directions. Its lateral branches are pendulous while its primary branches tend to curve upward. Lateral growth is approximately 20" per year.
4. Pinus strobus (white pine) 'Sea Urchin' is a miniature shrub with blue-green needles and is only 15" high x 22" wide.
5. P. strobus 'U Conn' is relatively fast-growing with bright green needles. It is 10' high x 8.5' wide and is his largest selection.
6. P. strobus 'Blue Shag' is moderately fast-growing with blue-green needles and remains very dense with mainly lateral growth. Size is 3' high x 5' wide.
7. P. strobus 'Green Shadow' is a 6' multi-trunked shrub with a rounded top and dark green foliage. It was found as a chance seedling and roots easily from cuttings.
8. P. strobus 'Blue Jay' is a dense, low mound 20" high x 50" wide. The foliage has a distinct bluish cast.
9. P. strobus 'Soft Touch' is a dense, flattened mound 2' high x 4' wide, with thin needles with a slight twist.
10. P strobus 'Old Softie' resembles a miniature weeping hemlock with soft green foliage and a cloud-like, billowy habit. After 27 years it is 4' high x 7.5' wide.
11. P. strobus 'Golden Candles' is an upright shrub 7' high x 5' wide with moderately dense branching. Both the candles and the current year's foliage are a bright golden color.
12. P. strobus 'Paul Waxman' is unusual in that it is more than twice as wide as tall. After 22 years, it is 2' high x 5'wide. The needles are green and blue-green, with the green ones being caused by the failure of the needles to separate in the fascicles as they should, thus giving the appearance of a single, thick needle.
13. P. strobus 'Coney Island' originated as a graft taken directly from a witches'-broom. Its form is cloud-like and is 30" high x 40" wide. The name is appropriate because of the presence of the large number of miniature cones that develop near the periphery of the shrub.
14. P. strobus 'David' is a tall growing selection with clusters of cloud-like branches at its outer fringes. The dimensions after 25 years are 15' high x 12' wide.
15. P. strobus 'Witches'-brew' is a 5' high asymmetrical shrub with dark green foliage that can be pruned to reveal its unique limb pattern.
16. P. densiflora (Japanese red pine) 'Low Glow' is a low mound with limbs ending in whorls of short, yellow-green needles and conspicuous buds. After 5 years it is 19" high x 45" wide.
17. P. densiflora 'Sunburst'
18. Tsuga canadensis 'Wind's Way'
19. T. canadensis 'Cotton Candy'
20. T. canadensis 'Howard Waxman'
21. T. canadensis 'Julianne'
22. T. canadensis 'Florence'
23. Sciadopitys verticillata 'Joe Kozey'
24. S. verticillata 'Wintergreen'
Dr. Towe is a member of the Azalea Chapter. He also authored the article "Shortcuts to Short Azaleas" which appeared in the spring 1994 issue of the Journal.