Cynoglossum

( sigh - noh - GLOSS - um )

At-A-Glance Information

These flowering perennials and biennials are commonly grown as annuals and are great for filling in beds and borders. They produce flowers in blue, white or pink and resemble Forget-Me-Nots (Myosotis). These flowers are native to Eurasia, Asia, New Guinea and Australia, and typically reach a few feet tall with green foliage and stems. Use these flowers as members of mixed beds or borders, in cottage, informal, or pollinator gardens, or in containers. Take care when planting these flowers in the landscape, as they are toxic to livestock, pets and humans.

Cynoglossum Species and Varietals

The genus Cynoglossum includes 75 species and is a member of the plant family Boraginaceae. The genus name Cynoglossum is derived from the Greek 'kunoglossen' (dog's tongue), referring to the shape and roughness of the leaves. The best growing zones for Cynoglossum vary depending on the species; for more information, see the descriptions below. To find your zone, click here: Zone Map.

Cynoglossum amabile (Chinese Forget-Me-Not, Chinese Hound's Tongue, Blue Showers)
This is a biennial plant generally grown as an annual, native to East Asia. It will grow best in USDA hardiness zones 5-9 or Sunset growing zones A2, A3, 1-24, H1 and H2. These plants reach 2 feet tall and 1 foot wide. Leaves are soft, hairy and grey-green and springtime flowers form in loose sprays of blue, pink, or white. Sow seeds in place in fall or early spring.

Cynoglossum australe (Australian Hound's Tongue, Australian Forget-Me-Not, Native Forget-Me-Not)
Native to Australia, these plants are commonly found growing in a wide range of habitats, from woodlands to grasslands to sandy dunes. These upright herbaceous perennials reach between 12 and 30 inches tall on average at maturity, and produce blue, pink, or whitish flowers in spring and summertime. This species grows well in USDA hardiness zones 8a-10b. Considered somewhat weedy but not invasive.

Cynoglossum creticum (Blue Hound's Tongue, Cretan Hound's Tongue)
These plants are native to the Mediterranean Basin, including the island of Crete, and is considered invasive in some areas of the United States (especially in Texas and Missouri). Flowers are blue, and bloom in spring and summertime. Check with your local authority before planting to see if this species is considered an invasive in your area. Cretan Hound's Tongue grows well in USDA hardiness zones 6-9 and is considered an invasive weed in Texas and Missouri in the United States, as well as South America (Chile), and Australia.

Cynoglossum germanicum (Green Hounds-Tongue)
These plants are native to Europe (first discovered in Germany, hence germanicum) and reach just under 30 inches tall when in bloom. They are biennials or short-lived perennials that produce shiny light green leaves and small pink flowers with large burgundy bracts. These plants grow well in USDA hardiness zones 6-12.

Cynoglossum grande (Adelinia grandis) (Western Hound's Tongue, Pacific Hound's Tongue, Grand Hound's Tongue)
This perennial grows best in USDA hardiness zones 5-10 or Sunset growing zones 4-9 and 14-24 and is native to Oregon and California coastal ranges and the slopes of the Sierra Nevadas. Leaves are hairy and plants generally reach 2.5 feet tall and 1 foot wide. They will die back in summertime to a heavy, underground root. Flowers appear in spring and are blue with white centers. Loves cool, woodsy soil and little summer water.

Cynoglossum lanceolatum (Lance-Leaf Forget-Me-Not, Small Hound's Tongue)
These many-branching perennials produce small blue flowers and are native to Ethiopia, South Africa, Madagascar, the Arabian Peninsula, and the Middle East through to China. These plants are cultivated and harvested in their native range by local populations as food and medicine. This species grows well in USDA hardiness zones 11 and 12 and is considered an invasive weed in India.

Cynoglossum officinale (Houndstongue, Hound's Tooth, Dog's Tongue, Gypsy Flower, Rats and Mice)
This species can either be an annual or a biennial, and produces greyish-green hairy leaves and reddish-purple flowers between the months of May and September. These plants are native to Europe and are an introduced species in North America. The common name Rats and Mice refers to the smell the plant exudes. This species does well in USDA hardiness zones 5-9, and is considered highly invasive in most of North America, namely in the Western United States, Canada, and the Midwestern United States.

Cynoglossum zeylanicum (Ceylon Hound's Tongue, Ceylon Forget-Me-Not, Indian Hound's Tongue)
These plants, native to Asia, can be found growing wild in many areas of North America. Flowers are sky blue, and foliage is green. This species is considered invasive in Florida, Louisiana, Mississippi, and Texas, as well as Puerto Rico, Chile, and the Caucasus region.

Caring for Cynoglossum

Plant Cynoglossum in full sun to partial shade. These flowers will perform best when they receive between 6 and 8 hours of direct sun each day. Seeds can be sown directly into the garden, or starts can be purchased at a reputable nursery. They prefer to be grown in well-draining soil that is rich in nutrients with a neutral to acidic pH. If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Mulch around the base of the plant with organic mulching material to help retain soil moisture and suppress weed growth. Keep mulch away from the plant stems, as this can encourage an environment for root rot issues to take hold. New plantings should be watered regularly as they establish a strong root system. Mature plants enjoy an evenly moist (but not soggy) substrate.

Each year in springtime, apply a 2-inch layer of organic compost around the planting area to improve soil structure, drainage, and nutrient load. This one feeding will be sufficient to carry the plants through their active growing and blooming seasons. Pruning is not necessary for these plants, though any damaged, diseased, or otherwise unsightly foliage can be trimmed off at any time during the growing season in order to clean up the look of the plant. Spent blooms can also be trimmed off, which will neaten the appearance as well as discourage plants from re-seeding and taking over garden beds.

Harvesting Cynoglossum
Flowers produced by species in this genus are commonly used in fresh flower arrangements, adding colorful filler. Flower stems are ready to be harvested when 1/4 to 1/2 of florets on a spray are open, which occurs in late spring through early summertime (typically May through July). The best time to harvest is in the early morning after dew has dried but before the heat of the day sets in. Using sharp, clean shears, cut the stem towards the base and immediately place it in a bucket of cool water. These flowers can be prone to wilting, especially in warm weather. Condition them for a few hours in a cool, dark space for a few hours before arranging them to ensure a 5 to 7 day vase life.

Propagation

Cynoglossum plants, because they are annuals or biennials that bloom in their first year, are best propagated from seed. They will re-seed freely in the garden, so if spent flower heads are left on plants, gardeners really do not need to do much to propagate them; volunteer seedlings can be dug up and moved wherever desired. To intentionally propagate Cynoglossum, or Chinese Forget-Me-Not, plants, follow the instructions below:

Propagating Cynoglossum by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. The seed heads on plants are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will continue to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
In either late winter or early springtime, get your container prepared. Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 5-10 from sowing.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 65 and 72 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Cynoglossum immature seeds on a flower stalk.

Cynoglossum seeds are somewhat spikey.

Problems and Pests

Certain species of Cynoglossum are considered invasive in some areas. See the species descriptions above for more information. Check with local authorities before planting. Although Cynoglossum (Chinese Forget-Me-Not) plants are considered pest and disease resistant for the most part, they can suffer from time to time from issues with the following: