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How to Grow Japanese Anemones (Windflowers)

Caren White is a Master Gardener and instructor at Home Gardeners School. She has been associated with Rutgers Gardens for over a decade.

how-to-grow-japanese-anemones-windflowers

One of my favorite perennial flowers are Japanese anemones. They are hardy plants that bloom at the end of the summer when my summer perennials are finished, but my fall perennials haven’t started to bloom. They keep my garden from looking empty and tired.

What are Japanese Anemones?

Japanese anemones (Anemone hupehensis) are not actually Japanese. They are native to China. Like chrysanthemums, they were imported from China to Japan where they became very popular. Japanese plant breeders created many hybrids increasing both the number of flower colors (white and pink) and flower shapes (single and semi-double). The plants eventually escaped cultivation and became naturalized in the landscape. Because Europeans “discovered” these plants in Japan, they assumed that they were of Japanese origin when they named them.

Japanese anemones are perennials hardy in zones 4 – 8. They prefer light shade, but will tolerate direct sun in the morning if they are in the shade the rest of the day. They also need to be well-watered. When blooming, the plants are 3 to 4 feet tall. They spread readily, so give these beauties enough space in your garden that they don’t crowd out the other plants. They do not like to be disturbed so they should only be divided every ten years.

The flowers open on top of long stems that are quite sturdy. Instead of falling down during windy conditions, they merely sway, giving them their name “windflowers”.

What makes these plants so popular is that they bloom in the late summer when other flowers are winding down. They are a great transition flower from summer into fall when the fall blooming plants such as chrysanthemums and asters start to blossom. The flowers can be either white or pink, single or semi-double. There are many cultivars to choose from, with pinks outnumbering the white flowers.

My favorite cultivar is Honorine Jobert.

My favorite cultivar is Honorine Jobert.

I am partial to heirloom plants and Japanese anemones have many heirloom cultivars. My personal favorite is called Honorine Jobert. It was bred by a plant breeder by the name of Jobert in 1858 in Verdun, France. He named it after his daughter, Honorine. The flowers are white on stems that are about 3 feet tall. It was awarded the Award of Garden Merit by the Royal Horticultural Society in 1993. In my experience, this cultivar is not as invasive as other cultivars. It blooms reliably every year in September and October. Each plant is covered with masses of flowers and the white really pops in my semi-shady garden.

How to Grow Japanese Anemones

Choosing a spot in your yard is critical. These are plants that prefer semi-shade. They don’t do well in full sun, especially if you don’t water them frequently. They can tolerate a sunny location only if you keep them moist. Most gardeners use them in their partial shady gardens. They are large statement plants, 3 to 4 feet tall. They look best in the middle or back of your border where they don’t overpower your other plants. They readily spread, so plant them at least 2 feet apart. There is no need to deadhead the flowers unless you want to keep the plants looking neat. The plants will not bloom again until the following year.

The cultivar, Bressingham Glow, is a good example of the semi-double flower form.

The cultivar, Bressingham Glow, is a good example of the semi-double flower form.

How to Divide Japanese Anemones

In general, Japanese anemones don’t like to be disturbed. Most gardeners give them lots of room in their gardens so that they only have to divide their clumps every 10 years.

To divide your plants, use a garden fork to gently dig them up. They have large fibrous roots, so start digging about 6 inches outside of your clump. Once you have lifted the entire clump from the ground, carefully clean the soil off of the roots then gently pry the roots apart so that you have 2 or 3 smaller clumps. Make sure that each clump has its own roots and foliage. Plant these new clumps at least 24 inches apart in your garden.

How to Grow Japanese Anemones From Root Cuttings

Unlike most plants which are propagated by stem or leaf cuttings, Japanese anemones are propagated by root cuttings. Root cuttings are taken when the plants are dormant in the winter or early spring. Carefully dig up your plant using a garden fork. Choose a root that is thick and healthy. Cut it off close to the crown of the plant. Then replant your plant. Take the root and cut it into pieces that are 3 to 6 inches long.

Plant the cuttings horizontally in a flat of moist soil and cover them with ½ inch of soil. Place the flat in a plastic bag to help the soil stay moist. New shoots should appear in a few weeks. When they do, remove the flat from the plastic bag. Place the flat in a sunny window. After your last frost, you can transplant your new plants into your garden spacing them at least 24 inches apart.

The seeds develop on the outsides of the pods like strawberries.

The seeds develop on the outsides of the pods like strawberries.

How to Grow Japanese Anemones From Seed

Japanese anemones are propagated by division or root cuttings because they are all hybrids and will not grow true from seed. If you are curious and want to see what kind of flowers you get from seed, you can harvest seeds from the seed pods on your plants and direct sow them into your garden in the fall. Don’t plant your seeds too deep. Just barely cover them with soil. They will germinate in the spring. Be patient. Plants grown from seed will bloom in their second year.

You can also start your seeds indoors 12 weeks before your last frost. Barely cover them with soil. Moisten the soil and then place the entire container in a plastic bag. Put the plastic covered container in your refrigerator for 3 to 4 weeks, to mimic winter weather. The seeds need a period of cold to germinate. After a month, remove the container from your refrigerator and remove the plastic bag. Your seeds should germinate in about 3 to 4 weeks. You can transplant your seedlings into your garden after your last frost. Do not expect to see any flowers until the following year.

© 2019 Caren White

Comments

poetryman6969 on October 02, 2019:

Lovely flowers.