Taxonomy, Plant Type for Autumn Joy Stonecrop Flowers
Here is how plant taxonomy breaks down Autumn Joy stonecrop. The genus is Sedum and the cultivar is 'Autumn Joy.' Technically, it is a cross between S. spectabile and S. telephium. Of the two parents, S. spectabile ("showy sedum") is the better-known. Sedums are referred to by the common name, "stonecrop," although "sedum," itself is so widely used as to be virtually a common name.
Do not, however, be shocked if you find this plant listed under different names. Some now use Hylotelephium as a genus name rather than Sedum. You will also occasionally see 'Herbstfreude' as a cultivar name rather than 'Autumn Joy,' due to the plant's beginnings in Germany. "Stonecrop" (or "Crassulaceae," in botanical lingo) is also the name of the overall plant family to which the Sedum genus belongs.
Features and Care
These sedums are upright and clump-forming. They measure roughly 2 feet by 2 feet at maturity. The plants are noted for their succulent foliage. Autumn Joy stonecrop bears an unusual flower well worth growing in its own right. Flowers are massed together in flat-topped heads that are 3 inches or more across. Autumn Joy's flowers, which start out greenish or whitish, can become orange, red, or pink. They appear in late summer or early fall.
At some point in fall, the blooms may take on coppery tones. Some gardeners prune the plant (reducing its size by half) in late spring or early summer to slow down blooming and keep the plant more compact.
The leaves, which grow in whorls, range in color from bluish-green or greenish-yellow to reddish-pink or almost off-white.
The 'Autumn Charm' cultivar sports variegated leaves. There are also newer versions that boast certain improvements over (or, at least, changes to) Autumn Joy, such as:
- ‘Autumn Fire,' which has pinker (lighter) flowers.
- 'Mr. Goodbud,' a good choice if you want, conversely, darker, more purplish flowers.
- 'Hot Stuff,' which is more compact.
- 'Iceberg,' which has mainly white flowers.
Some gardeners cut down the old stalks in fall, others wait until spring. It is really up to your individual tastes. The benefit in leaving them alone is that they give you a bit of winter interest, in two ways:
- Wild birds eat the seeds.
- The seed heads (which eventually become a brown color) look nice against a snowy backdrop.
Divide this perennial in spring if your desire is to acquire more of it for free.
Sun and Soil Needs, Planting Zones, Companion Plants
Grow these sedum plants in full sun to partial shade and in well-drained soil. Other than that need, they are not fussy about soil. They are drought-tolerant perennials once mature and can be grown in USDA planting zones 3 to 9.
Here are some ideas for companion plants:
- Plants with silvery leaves.
- Ornamental grasses.
- Nasturtiums (Tropaeolum).
- Flowering cabbage/kale (Brassica oleracea).
- Russian sage (Perovskia atriplicifolia).
- New England asters (Symphyotrichum novae-angliae).
Uses for Autumn Joy Stonecrop in Landscape Design
This perennial is used in border plantings, in cottage gardens, and in rock gardens. Its relatively late blooming period (the source of this cultivar's name) is useful for those trying to achieve four-season interest in their yards. Many other perennial flowers have ceased blooming by the time that this one comes into flower.
Being drought-tolerant, it is considered a good choice as a xeriscaping plant. While you will achieve peak display if you water during dry spells, mature plants will most often survive all but the worst droughts in the northeastern United States, for example, with minimal watering.
But flowering may be reduced as a result. There is actually a disadvantage to watering (and fertilizing) too faithfully: When growth is vigorous, plants can flop over, thereby requiring staking. So cutting back on water and fertilizer can save you some work in growing these plants. Another trick for avoiding having them flop over is to give them full sun.
On the good side, sedum plants will attract butterflies and bees. On the bad side, they also draw slugs, mealybugs, scale insects, and deer pests. You will have to inspect your plants carefully to detect signs of the mealybug and scale, since these are very small pests. Upon detection, immediately spray with Neem oil.
Other Types of Sedum
A few other kinds of stonecrop are widely available to gardeners at nurseries (generally suited to zones 4 to 8), including:
- S. rupestre 'Angelina' (creeping, with golden spring foliage and yellow flowers).
- S. spurium 'Dragon's Blood' (creeping, with red spring foliage and pink flowers).
- S. 'Acre' (creeping, with green leaves and yellow flowers).
- S. 'Frosty Morn' (bicolored foliage and pink flowers).
- S. 'Matrona' (bronzed foliage and pink flowers).
- S. 'Xenox' (bronzed foliage and pink flowers).
- S. spectabile 'Brilliant' (blue-green leaves and rosy-red flowers).
Especially popular are upright types that have dark foliage and pink flowers, including:
- S. 'Chocolate Drop'.
- S. 'Cherry Truffles'.
- S. telephium 'Marina'.
- S. 'Touchdown Teak'.
- S. 'Black Jack' (the cultivar with perhaps the darkest leaves).