Want to add some height and drama to your plantings? Select some plants that hold their flowers on tall stems, or spikes. These generally include many flowers arranged either individually or in clusters around the stem. I like them in drifts when possible, but depending on your choice, one plant may put up a multiple of spikes. Above is yellow Jerusalem Sage (Phlomis), an elegant relative of bee balm. I am hopeful mine will finally bloom this year.
I love the elegant stems of Monkshood in my garden, which also are much more reliably perennial for me than their relatives the delphinium. They also bloom at different times; this white one comes in mid summer, but I have two fall-blooming varieties as well, in deep blue and bicolour blue and white. They offer a nice, cooling counterpoint to the normal autumn palette of golds, reds, oranges and bronzes.
I've mentioned this plant before but it bears repeating. New in my garden last year was Digiplexis, a cross between Digitalis (foxglove) and a non-hardy tropical relative. This won't be hardy here, but it bloomed like crazy and in different hues than the traditional foxglove, so I hope to find it again next year. Maybe it will self-seed but if it does it will likely revert to Digitalis form. We'll see!
I like to tell people not to be too hasty to deadhead their perennials, because some have very nice seedheads. Dictamnus, the dittany or gas plant, is a good example of this with its star-shaped seedheads.
Here's the Dictamnus (the white form) in flower. Not only are the blooms lovely, they are extremely fragrant with a lemony scent. Slow to establish but worth waiting for.
Here's a striking perennial that ought to be grown more often: Kniphofia, also known as red-hot poker, foxtail or torch lily. Most varieties come in shades of yellow or orange, with some colour changing as the flowers age. It is drought tolerant once established which also means you need to plant it where it will have great drainage.
I used to be rather neutral about penstemons, because 'Husker Red' did not thrive for me in my former garden. Then I tried a couple of annual varieties that flowered like crazy, which prompted me to try a perennial form or two again. This was fed by friends who are very fond of penstemons and grow numerous species. Now I have...a bunch of penstemons. This one is called 'Dark Tower.'
And this is one of the species, Penstemon strictus, Rocky Mountain penstemon. With those colours in the flowers, it's no wonder I'm fond of it!
Lambs ears (Stachys byzantina) may be an 'old fashioned' perennial, but it's one everyone should include in their gardens. For starters, it's deer-resistant, for those plagued by bambi-itis. For seconds, its foliage is grey-green and fuzzy, adding a distinct colour and texture to your garden as well as the vertical effect. And if you do plant it, don't cut the flowers off--maybe they aren't the most showy, but pollinators LOVE them.
There are many different types of lupin and their relatives out there. Here in Atlantic Canada, we have lupins growing wild in many places, along roadsides, in meadows, and of course we grow them in our gardens, too. They are imprinted as one of the first flowers I learned the name of, in part because my maternal grandmother grew them in her garden. There are numerous hybrids and colours now available, but I find the unusual colours like red and yellow don't tend to last.
To get around that problem with yellow lupins that don't act perennially, I grow two different types of Thermopsis, or yellow false-lupins. They are related, obviously, and as an added bonus, the species I grow produce rather handsome black seedheads which look quite striking in flower arrangements or just standing in the garden.
This has highlighted just a few perennials with spiky stems--there are many, many more, and of course there are annuals too, and I didn't even touch the grasses! What's your favourite for adding vertical accents to your garden?