Old Favorites, New Cultivars
The perennial world is plastered with marketing for new plants, many of which have not been sufficiently trialed under consumer-like conditions. I may be a certified landscape designer, a long-time horticulturist, and a gardener, but I like to think of myself as a typical consumer, in that I am so busy, that plants - once installed - have to fend for themselves, albeit having the benefits of an irrigation system. Unlike many gardeners, I do keep records, so I can tell you that the perennials discussed in this article were planted in my garden in 2014.
Astilbe Sugarberry' is a dwarf, growing only 12 inches high with soft, pink plumes that resemble a fluffy starburst. Part of the Short n Sweet" series, it blooms in mid-June for approximately three weeks. I still enjoy the deadheads as a structural element. The foliage is glossy green. Like most Astilbe, this one benefits from some shade. Mine are planted at the top of a south facing slope but are shielded by the taller foliage of other perennials and, in June, by the large heads of Allium christophii. The soft, pink plumes blend well with the soft lavender of the Allium and with the purple foliage of the neighboring Berberis Concorde', a sterile cultivar of Barberry.
Heuchera Glitter' has many incarnations, depending on its siting. Most catalogs show it as a silver-leafed cultivar with black veins. However, seen in full sun in April 2016 at the Cincinnati Zoo and Botanical Garden, it was a silver-burgundy. In my garden, facing east but also getting some afternoon sun, the leaves are purple with a silver glaze. This Heuchera blooms in mid-May with bright, pink clusters of tiny bells. The foliage is about 8 inches high and the flower stalks are 15 inches high. Although this bed is irrigated, Glitter' is at the edge, so the drip doesn't always extend that far; thus, I will say that this Heuchera is relatively drought-tolerant.
I love garden phlox but only the ones that are mildew resistant. Many cultivars are supposedly in this category but few are the ones that actually deliver. However, add Glamour Girl' to your list of performers. Starting in mid-July, the coral-pink flower clusters will knock your socks off and they will continue blooming well into September. The foliage is always a clean green. Phlox Glamour Girl' grows about thirty inches high, perfect in my back garden to hide the yellowing foliage of Dicentra spectabilis as it temporarily goes dormant in mid-June. Of course, full sun and average moisture is essential. This is the only perennial in this article that is not deer-resistant but, happily, the deer have ignored it.
When it gets really hot, it's time for the next act in the garden and that's when you want to feature Hibiscus Heartthrob'. Just give it lots of water and it will bloom its head off, from late July/early August well into September. The dark red flowers are huge and even the deadheads are large and beautiful. Catalog photos show the flowers as more burgundy than mine and perhaps they would be in full sun. Most of my hibiscus are sited in full sun but this one doesn't seem to mind being in partial shade. Only four feet tall, it easily fits into my landscape.
Moving now into mid-August, many gardeners forget to add perennials that are late bloomers in order to keep the garden fresh. For many years, heleniums were tall and straggly but more recently, that has changed. Now we have Helenium Short and Sassy' about which I have already written and the new Mariachi series. Last year, I planted Helenium Mariachi Salsa' and I love it. It supposedly only grows eighteen to twenty inches high but this year, as a result of all the early rain, it is thirty inches high. Most of the cultivars that are described as red are actually orange but this one is as close to red as I have seen, especially when viewed up close. This is basically a native tall prairie plant that has been refined. Full sun is the ticket.
These are some of the best of the new and I encourage you to use them.