 Delphinium exaltatum |
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English delphinium breeders produce hybrids of show-stopping exhibition quality named plants. There are the hybrids produced from the D. elatum growing to six feet or more in height. Semi and fully double blooms come in siren-song colors of 'mulberry pink with contrasting bees of brown', or dark royal blues with a contrasting bee of soft white. Delphinium flowers have five petal-like sepals joined at the base with the upper sepal spurred. The two to four petals in the calyx throat are furry-looking and referred to as a "bee". That fuzzy looking thing in the middle of a delphinium bloom.
Each spring American gardeners are a bit like deer staring into an on-coming car's headlights. The 'better' gardening magazines will have feature articles filled with color photos. Garden centers and local nurseries will carry seedling plants with full color pot labels. Catalogs and web sites fill in any local lack of plants. As with the deer, we simply can not seem to see any other delphinium.
Each year we bring home plants or seeds for our gardens only to be disappointed. These lines of hybrids are bred for weather far different than found here in the Midwest. The elatum hybrids simply can not stand up to our summer temperatures. Just as they come into bloom, here locally we go into hot and dry with high humidity, and night-time temperatures that remain at a level where these hybrids can not rest.
There are delphiniums native to the mid-west. To the best of my knowledge no one has put a selective breeding program in place for our local natives. Thus there are no fully double or semi-double blooms, no highly contrasting bees, and named color lines. We are long over due for someone to introduce named cultivars of our native Delphinium exaltatum, or tall larkspur. This species is a native ranging from Pennsylvania and Ohio into Alabama south. It can be found growing in open fields, woods and woodland margins. That is a species performing in sun or shade, differing soils and moisture needs, making for an easy to grow perennial in the native garden or more formal beds.
Mine are on the west and south of my woodland garden where they receive the setting sun. One site has heavy clay, the other classic humus-rich, well-drained, garden soil. Both sites produce plants three feet, or more, in height. The lavender-blue blooms are numerous at the top of stiffly upright, but slender and graceful, stems. In all the years I have grown this delphinium species, the thought of needing to stake has never presented itself. Even during full bloom and wet weather, the tall larkspur remains upright. When the summers turn hot and dry, the tall larkspur continues on unfazed in my garden. Foliage stays fresh and bloom period is not reduced. The foliage on elatum hybrids will often pick up mildew at this point, but not our native exaltatum. I have yet to see a case of mildew on my plants in either location. After each flush of blooms I cut back the bloom stems, deadheading the plant. Each time a bloom period has finished, if the plant is cut back, another period of bloom will occur. I have cut back my plants twice in a season having blooms in my garden into the middle of December during a mild fall and early winter. The blooms will take light frosts before shutting down for the season. I count on a reliable bloom period from July into winter of each year.
With such a long bloom period it is not hard to think of companions. Phlox is certainly one of the better companions. Tall garden phlox (P. maculata or P. paniculata) are favorites, as is Phlox glaberrima. Native Aster species and cultivars, Eupatorum or Mistflower and Lilium supurbum or Turk's cap lily are just a few others coming to mind.