Big, bold perennials
There are times when gardeners are looking for a very large perennial for the back of a perennial bed or to provide screening of an object or an area in a yard. There are a number that are very interesting and attractive that will fit this criteria.
The following are all recommended for full sun locations. Size may vary according to soil type and available moisture. But all will be large plants.
The cup plant (Silphium perfoliatum) is a native plant of the aster family. It derives its name from the leaves which clasp the stem and will retain water in this “cup.” It can get up to 7 feet tall and blooms with yellow, daisy-like flowers. This is growing in the Master Gardener’s pollinator garden on East Burdick Expressway in Minot.
White or giant fleece flower (Persicaria polymorpha) grows 6 to 8 feet tall and almost as wide. The large, Astilble-like flower panicles last from 4 to 6 weeks and are very showy.
Joe-Pye weed (Eutrochium purpureum) is another native flower that will reach up to 6 feet in height. For those wanting a smaller version, the variety “Little Joe” grows to 3 to 4 feet in height. The flowers are highly fed upon by bees and butterflies.
Culver’s root (Veronicastrum virginicum) is a native species which grows to 5 feet with long spikes of light blue flowers.
Golden clematis (Clematis tangutica) is a vigorous growing, very large clematis with yellow, bell-like flowers. It can grow to 15 or more feet in height.
Big head knapweed (Centuria Macrocephalata) grows to 4 feet tall with a large (3-3.4 inch wide), bright yellow flower. It is very striking, but can be a invasive so be sure to dead head it after flowering.
False blue indigo (Baptisia australis) is a native legume growing 3 to 4 feet tall. It has tall flower spikes of pea-like flowers. The seed pods turn a striking black color, and if left on the plant over winter make a nice winter garden contrast.
There are a number of big, bold plants for shade gardeners. The following will make a bold statement in a shade garden.
Hosta come in a wide range of sizes. But the large ones will get up to 3 feet high and 4 feet wide. Varieties include Empress Wu, Victory, Dream Weaver, Big Daddy, and T Rex. Sum and Substance Hosta is an exception because it will grow in full sun if given sufficient water. If grown in full sun it will have an almost golden color.
Ligularia come in a variety of leave colors, many which are burgundy or bronze, and have varying leaf patterns and flowering patterns. But all are heavy shade and water lovers, but add very nice vertical contrast to a shade garden as well as color and texture contrast in the burgundy and bronze colored varieties.
Snakeroot or also called bugbane is a slower to establish, tall shade perennial. There are a number of varieties that produce tall flowering spikes. They can tolerate more dry soil than most shade plants. Some varieties have dark burgundy and almost black foliage which is a nice color contrast.
Goat’s beard – Aruncus (Aethusifolius Dioicus), is a tall perennial with tall white flower spikes. There are also some smaller varieties, but this is the largest and will get up to 5 feet tall and wide.