Linum

( LYE - num )

At-A-Glance Information

Linum, or Flax, is a genus of perennial and annual flowering herbaceous plants that need full sun and moderate water to perform well in the garden. Flowers have a delicate fragrance and are held on upright stems, blooming over a long period (typically between 8 and 12 weeks), though each individual blossom lasts just a day. Grow Linum massed together, in mixed beds and borders, and as members of cottage, informal, pollinator, prairie, meadow, Mediterranean or native gardens. Take care when planting these flowers in the landscape, as ingestion of plant parts is toxic to livestock.

Linum Species and Varietals

The genus Linum is a member of the plant species Linaceae and includes 200 species. Flax growing zones vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Linum alpinum (Alpine Flax, Mountain Flax)
These plants form either decumbent or erect stems reaching between 4 and 20 inches long. Flowers are relatively large, and form in loose clusters of between one and eight blooms. Blossoms are light blue to light lavender in color, and are present on plants from May through August. This species is native to western Asia and southern Europe. Best in USDA hardiness zones 4-8.

Linum arboreum (Tree Flax, Evergreen Flax, Shrubby Flax)
These plants are native to Greece, Crete, the Aegean Islands, and Turkey. These plants form subshrubs that reach between 9 inches and 2 feet tall when mature. Flowers are light yellow to medium yellow in color, and bloom in spring and summertime. Foliage is fleshy and green. These plants are occasionally grown as garden ornamentals. This species is suited for USDA hardiness zones 8-10.

Linum bienne (Pale Flax, Narrowleaf Flax, Narrow-Leaved Flax)
These plants are native to the Mediterranean and Europe and prefer to grow in low grasslands. They are suited for USDA hardiness zones 5-9. Flowers are produced in late springtime, and remain on the plants through summertime, especially in mild weather regions of the world. Blooms are pale blue, streaked with a darker color. This species is considered potentially invasive in New Zealand, South America (Chile and Argentina), and Hawaii, California, Pennsylvania, and Oregon in the United States.

Linum flavum (Golden Flax, Yellow Flax)
This species of Flax grows in USDA hardiness zones 4-9 or Sunset growing zones 2-24 and is a perennial plant native to southern and central Europe. Grows 12-15 inches tall and a foot wide. The base is a bit woody, and grooved branches sprout green leaves. Flowers bloom in spring and summertime and are yellow, blooming in clusters.

Linum grandiflorum (Flowering Flax, Scarlet Flax, Red Flax)
This is an annual species that is native to North Africa and grows well in USDA hardiness zones 3-10 or Sunset growing zones 1-24. It reaches 2.5 feet tall and 12 inches wide, and is often included in wildflower mixes. Variety 'Rubrum' (pictured), also known as Scarlet Flax, has blooms in bright red.

Linum lewisii (Blue Flax, Prairie Flax, Lewis Flax, Western Blue Flax)
This species of Flax is a perennial which grows in USDA hardiness zones 3-9 or Sunset growing zones A1-A3, 2-12 and 14-18 and is native to the western areas of North America. It reaches up to 3 feet tall and produces sky-blue flowers in spring and summer. This species does well in high elevations.

Linum narbonense (Perennial Flax, Blue Flax, Narbonne Flax, Spanish Blue Flax, Mediterranean Blue Flax)
This perennial flower is best in USDA hardiness zones 5-9 or Sunset growing zones 3-24 and is characterized by its wiry stems. It is native to the Mediterranean and reaches 2 feet tall and 1.5 feet wide. Flowers are blue with a white eye and bloom in late spring and early summertime.

Linum perenne (Perennial Blue Flax, Lint Bells, Prairie Flax, Blue Flax)
This species is perennial and grows well in USDA hardiness zones 5-9 or Sunset growing zones 2-24; native to Europe and central Asia. It is a vigorous plant and reaches 2 feet tall and 1.5 feet wide, and has blue flowers that bloom in spring and summertime.

Linum strictum (Rigid Flax, Upright Flax, Upright Yellow Flax, Lino Amarillo, Ilinet Estricte)
This species of flax produces rigid stems and is endemic to the Mediterranean region. Flowers are light golden-yellow and small, blooming between February and May in their native range. These plants are grown principally for their use in making linen cloth. This species is suited for USDA hardiness zones 5-9.

Linum suffruticosum (White Flax, Pyrenean Flax, Woodsy Flax, Sessile Flax, Wild Flax)
This species is native to Spain, and produces a small shrubby plant with green foliage and white flowers, though plants are variable in habit and flower color. White Flax is suited for USDA hardiness zones 5-9.

Linum usitatissimum (Flax, Common Flax, Linseed)
This species produces the material used to make traditional linen fabrics for use in bed sheets, underclothes, and table linens. The oil produced by these plants is called Linseed oil, an edible oil used in cooking as well as in many other manufactured goods and materials. These flowers grow well in USDA hardiness zones 3-9.

Caring for Linum

Take care when planting these flowers in the landscape, as ingestion of plant parts is toxic to livestock. Linum, or Flax, plants perform best when situated in a warm spot that receives full sun to light shade. The more sun these plants get, the better they will flower, but they do appreciate some late afternoon shade, especially in warmer climates. Ensure that soil is well-draining, fertile, and has a pH of between 5.0 and 7.0 (slightly acidic to neutral). 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. Water newly planted Linum regularly to help it develop a strong root system. At maturity, these plants are drought-tolerant, able to get by on rainwater alone with some supplemental waterings in the warmest months of the year.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Flax plants are sensitive to fertilizers. Halfway through the blooming season, plants can be deadheaded to extend the flowering period. In summertime after plants finish flowering, cut the plants back by half to encourage a more bushy form. There are both annual and perennial species of Linum. Annuals are typically dug up and composted at the end of the growing season, or can be left in place to enrich the soil. Perennial species can survive for between 3 and 5 years in most cases, and are then replaced. Both annual and perennial species will freely re-seed in the garden, providing new flowers for the landscape indefinitely.

Propagation

The simplest and most straightforward way to propagate Linum plants is by harvesting and sowing seed.

Propagating Linum 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.
Linum seeds may benefit from a period of cold stratification before they are sown. Place harvested seeds in a damp mixture of sand or peat moss in a sealable container or plastic bag, and place the container in the refrigerator for between 4 and 8 weeks. Remove the seeds from their bed after the cold stratification period, and soak them in lukewarm water for between 12 and 24 hours. Viable seeds will sink, and any that float can be discarded, as they will not germinate.
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 between 20 and 30 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
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.

Problems and Pests

Certain Linum species are considered invasive in some regions; see the species descriptions above for more information. Check with local authorities before planting. Linum, or Flax, can be susceptible to developing issues with the following pests and diseases in the home garden: