The various species vary considerably in size, but all have basal leaf clumps from which long flower stems rise to support delicate flowers two to five inches in diameter. Flower colors also vary depending on species and variety. The flowers are usually simple single blossoms though some varieties do feature double flowers similar to a frilly, oversized mum. Anemones are usually planted from bulb-like corms or bare roots in the fall or in the late winter or early spring. They are fast-growing plants that will flower in their first season. Life expectancy depends on species; some are relatively short-lived while others can live for decades. The plants contain a substance called protoanemonin, which makes all parts of anemone plants moderately toxic to humans if large quantities are ingested and mildly toxic to pets. Some species, such as A. coronaria (often known as poppy anemone) have roots that resemble bulb-like corms. The small corms are planted in groups, like tulips or daffodils. Place them in clusters spaced about one inch apart and two inches deep. Let nature dictate the spreading of the cluster. With corm-types, leave the foliage in place until its foliage dies back naturally before removing it. Other species, including A. hupehensis (sometimes known as Japanese anemone), have tuberous or rhizomatous roots that are planted in small groups about three to six inches deep. Be generous when you plant the petite spring anemones; these low-growing plants that range from 3 to 15 inches in height look best when planted in groups of 50 or more. Whatever the species of Anemone, these plants generally like at least four hours of sun each day and well-drained soil that is relatively moist. Once planted, they are relatively carefree plants. The types with rhizomatous roots will need to be lifted and divided every three years or so.
Light
Most species of anemones should be planted where they receive at least half a day of direct sunlight. Some varieties thrive more in partial shade, but they should still receive at least four hours of sun daily.
Soil
Plant anemones in moist, well-drained soil. Before planting, you can improve the soil by adding compost, leaf mold, or other organic matter. Anemones aren’t fussy about soil pH, but will thrive best in slightly acidic soil.
Water
Water the plants regularly when rainfall is less than one inch per week. Keep the soil lightly moist by watering slowly to allow the soil to absorb as much water as possible. Some varieties have special water needs; for example, wood anemone (A. nemorosa) dies to the ground in midsummer and does not need water until it regrows in fall.
Temperature and Humidity
Anemones like relatively cool temperatures. Most species do best with daytime temperatures are 58 to 65 degrees Fahrenheit and nighttime temperatures are 42 to 50 degrees. Gardeners in USDA hardiness zones 3 to 10 will be able to find at least one Anemone species that will thrive, but no single species can adapt to all zones. A. blanda and its cultivars are appropriate for zones 4 to 8, for example, while A. coronaria and its cultivars are able to grow in zones 7 to 10. Gardeners in cold-winter zones might choose to grow tender anemones as annuals, planting new corms each spring. Anemones have no special humidity requirements provided they are receiving proper soil moisture.
Fertilizer
If desired, you can add bone meal to the soil in the fall for spring bloomers or in the spring for fall bloomers to give the plants a nutrient boost. No additional feeding is needed or recommended.
Types of Anemones
Several species of Anemone are available, each with several named cultivars to choose from:
Anemone blanda adapts well outdoors and is hardy in zones 4 through 8. This plant is sometimes known as Grecian windflower. Some notable cultivars include ‘Blue Star’, ‘Pink Charmer,’ and ‘White Splendour’.Anemone coronaria, has poppy-like blooms with black centers and are popular in floral arrangements. This species, sometimes known as poppy anemone, is reliably hardy only in zones 7 through 10. Some recommended cultivars include ‘Lord Lieutenant’, ‘Mount Everest’, and ‘Sylphide’,Anemone hupehensis var. japonica, the Japanese anemone blooms abundantly from mid-summer to late fall, giving gardeners a shade-loving alternative to the sun-drenched mums and asters of autumn. It is grown in zones 4 to 8. Some recommended cultivars: ‘Bressingham Glow’, ‘Pocahontas’, ‘Praecox’, and ‘Pamina’.Anemone sylvestris (sometimes known as snowdrop windflower) is an early spring bloomer that does not have time to attain great heights; it belongs at the front of the border. You can grow it in zones 4 to 8.Anemone canadensis is a North American native wildflower that is hardy to zone 3. It blooms from April to June.Anemone nemerosa (wood anemone) is hardy in zones 5 to 8 and is a short give- to eight-inch plant with white flowers. Several cultivars are available, including the pink-flowering ‘Robinsoniana’.
Pruning
The fading foliage of spring bloomers is usually insignificant enough to wither away unnoticed, so you will not need to prune it for a tidy-looking garden. Taller fall-blooming varieties might look shabby after the first frost, so shear off dead growth as part of your early winter clean-up tasks.
Propagating Anemones
Though the different species of anemones have different root structures, all can be propagated by digging up the corms/tubers, dividing them, then replanting. Lifting the roots in fall for winter storage is a good idea if your garden experiences wet soil over the winter. Here’s how:
How to Grow Anemones From Seed
Seed propagation of anemones is a slow, unpredictable method that is generally practiced only by serious amateurs or by professionals developing new cultivars by disciplined cross-pollination. But if you want to try seed propagation, collect the seeds from dried seed heads left after the flowers fade, and sow them in an outdoor cold frame filled with loose, well-draining soil mix. Just barely cover the seeds. After they sprout, allow the seedlings to remain outside over winter under a thick layer of mulch, then transplant them individually the following spring. If you wish to start the seeds indoors in pots or trays, the seeds will need a cold stratification period of three to four weeks before you sow them in a bright location to sprout.
Potting and Repotting Anemones
Not all Anemone species adapt well to growing in containers, but one that does is Anemone coronaria, of which there are many cultivars. Use a large pot filled with ordinary commercial potting soil blended with well-decayed compost. It’s generally best to use a large 12- to 14-inch container. Corm-types should be spaced at least four inches apart; rhizomatous types should be planted one per pot. Potted anemones do not adapt well to growing indoors, though they can be overwintered in an unheated greenhouse or another sheltered area where they can receive the necessary winter chill period. When the plant becomes root-bound (an issue only with the rhizomatous types), divide the root clump and replant.
Overwintering
Provided the species being grown is appropriate to your hardiness zone, no special winter protection is needed for anemones. Most gardeners simply trim off the flower stalks and foliage near ground level as part of the general winter cleanup work in the garden. If you are growing a species that is borderline hardy for your region, a layer of mulch over the root crowns can protect the roots from winter kill.
Common Pests & Plant Diseases
Although there are no truly serious pest or disease problems with Anemone, they can be stricken with foliar nematodes that feed inside the leaves. These microscopic soil worms can cause distorted leaves and flowers through damage to the plant cells. Treatment is difficult, but removing plants and heating the soil through solarization sometimes gets rid of nematodes. All plant material in the afflicted area will need to be removed and disposed of. Periodically tilling up the soil and allowing it to bake in the sun might rid the area of nematodes. A variety of fungal leaf spots, downy mildew, and powdery mildew can affect Anemones though the diseases are rarely serious.
How to Get Anemone to Bloom
Most Anemone species bloom readily provided they are growing in moderately rich, moist soil. When plants stop blooming, it is usually because the roots have become over-crowded. Lifting and dividing the root clump or corms, then replanting, will usually return the plant to robust flowering. A yearly application of bone meal blended into the soil can also provide the mild boost needed to support good flowering.
Common Problems With Anemone
Anemones are relatively care-free flowers that are only subject to a few issues:
Flopping Flowers
It’s generally desirable for anemones to sway in the wind, but some species can lose the ability to stand upright. Taller anemones might need to be staked to prevent them from flopping especially when they are not receiving enough sunlight.
Holes in Leaves
This can happen if snails or slugs come to visit. If these pests becomes a problem, small saucers of beer or snail/slug bait will do the trick.
Plants Die Out Over Winter
An unusually cold winter—or one that saw unexpected thaws followed by a hard refreeze—can cause some Anemone species to perish. There’s no solution other than to re-purchase and replant. If this is an ongoing problem, you might consider digging up the corms or roots to store for the winter for yearly replanting in the spring. As winter approaches and the foliage dies back, dig up the corms or rhizomatous roots and place them in a bag filled with dry peat moss. Store them in a cool, dry location for the winter. Before replanting in the spring, give the bulbs or roots an overnight soaking in water to rehydrate them. Discard any corms or roots that are noticeably rotted or shriveled.
