The fact is, I am short. Not extremely short, but short enough so that I require the assistance of a step stool or an obliging tall person to reach high shelves. If I were a garden plant, I would be a good mid-border specimen—not tall enough to dominate the back and not short enough to use as an edger. I like to think that in the garden of life I am a peach-leaf bellflower or perhaps a Shasta daisy.
All of this came to mind the other day when I set out in search of some tall, back-of-the-border plants. I have been concentrating so much of late on intimate specimens such as hardy geranium and tiny leaf hostas, that I have neglected to cover my rear—so to speak. I don’t want this to be a chronic problem, so it is time to take action.
Ideally there should be something tall blooming or looming at the rear of your beds spring, summer and fall. One of the most obvious answers to this dilemna, and one of the most frequently overlooked is to install a very small tree. Some of the most attractive petite trees are members of the Salix or willow family. These grow between 4-6-feet high and 2-4 feet wide; tall enough to provide the requisite height, but not so tall or wide that they shade everything for miles around. Salix caprea ‘Weeping Sally’ is one of these willows, and in the spring it emulates its relative the pussy willow and covers its branches with silvery catkins. Thereafter it is bedecked in weeping green foliage. ‘Weeping Sally’ is a lovely little tree, and especially appropriate for Asian-themed gardens.
If one of the short members of the Salix family doesn’t fill the bill, then you might try a dwarf fruit tree or even a standard rose. Just make sure to check that the particular dwarf tree is cold hardy in your climate zone.
Unless you are talking about small trees, there is not much that reaches a reasonable height by early to mid spring. In May though, Allium ‘Globemaster’ attains a height of 3-4-feet, dominating the back of the garden like giant purple lollipops on sticks. The flowers are huge and have the added bonus of lasting at least a couple of weeks. Given congenial circumstances, German iris (Iris germanicus) can also soar to respectable heights.
By the time late spring and early summer rolls around things usually begin to take off, literally and figuratively. Hollyhocks and some other members of the mallow family are nothing if not tall. I especially love Malva sylvestris ‘Zebrina’, which was extremely fashionable a few years ago. This summer star has flowers that are cream to pale mauve with dark purple veins and stripes. In my experience they self-sow rather prolifically, thus insuring something delightful at the back of the border for years to come.
Another long tall purple drink of water is Liatris ligulistylis, a species of liatris or gayfeather. This rises above the garden floor to a height of 3-5-feet, with fuzzy flower spikes that attract all kinds of butterflies, not to mention goldfinches.
If your climate is not terribly torrid, delphinium is a winner for the back of the summer border. Some cultivars can grow as tall as 7-feet, but most restrain themselves to between 4-5-feet. The range of colors seems to be increasing all the time with breeders making delphiniums that are ever rosier or creamier or darker purple.
For something taller and more tropical, try raising canna in pots or installed directly in the ground. Just remember to dig up the tubers and store them inside come fall. Lilies can also be quite statuesque, especially the Asiatic varieties, and they come in colors to match just about any garden scheme.
Naturally, shade gardeners want tall specimens just like their neighbors on sunnier lots. For them there is Korean angelica (Angelica gigas). This plant has purple flowers and grows between 4-8-feet tall. If you are one of those people who make fruitcake, either for your own family or to inflict on others at holiday time, you can candy the angelica stems for inclusion in the batter. Angelica is a notorious self-seeder, so once you have it, you can plan to continue making fruitcakes until you are too old to do so.l
Late summer is the time to marvel at the Himalayan lily (Cardiocrinum gigateum). It is not a true lily (though it has trumpet-shaped blooms), but it is truly tall, topping out under the most ideal conditions at 12-feet. For better or worse, most of us will have to content ourselves with Cardiocriumun that reach 6-9-feet.
If you are lucky, the rear of at least one of your beds is home to a few Joe Pye-Weeds (Eupatorium purpureum), the roadside stalwarts that bloom in the fall in rosy purple splendor. They require almost no care, reach heights between 5-7-feet and adore damp soil, making them useful for those difficult boggy spots that some people seem to have. Flank Eupatorium with some Snakeroot (Cimicifuga simplex), which is just a tad shorter and has striking white flower spikes. Both species can even take a bit of shade if you have it.
Exotic Cardiocrinums are fine if you are in the mood to seek them out. If not, go right down to the garden center and buy a package of one of the tall sunflower varieties. Plant the seeds in a sunny spot, add water and wait. By the end of the summer you will have stalks as tall as anyone could want with minimal effort. The neighbors will be impressed, and even if you are not tall, you can have the satisfaction of watching the huge golden heads tower over much of the rest of the world.
by E. Ginsburg