Scarlet Flax Plant Care: How To Grow Linum Grandiflorum

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The bright crimson flowering Linum grandiflorum is part of the Linaceae family a flax species native to Algeria, Northern Africa, Southern Europe, and North America as an introduced species.

The stark contrast between the red blooms and green foliage is why the plant is favored by gardening enthusiasts. Linum grandiflorum [LIN-um, gran-dih-FLOR-um] creates a dramatic look accenting any other bright annuals planted around it.

Flowering red Scarlet FlaxPin

The plant gets its common names from the red flowers, edged in black. You may hear it called by its common name including:

  • Scarlet Flax
  • Flowering Flax
  • Red Flax
  • Crimson Flax

Some varieties are known by their botanical name L. grandiflorum rubrum (linum grandiflorum rubrum).

Scarlet Flax Care

Size & Growth

The Linum Flax species is one of the easiest to grow flowering plants in the genus. The plant itself is very hardy and can grow in a variety of growing conditions.

Whether you plant it in planters, pots or dot it around garden beds, flowering Flax thrives come spring.

The herbaceous perennial can grow between 12″ – 18″ inches in height and spread almost 6″ – 9″ inches wide.

The plant grows erect branches laden with ½” inch long waxy green leaves which form on large mounds of elegant branches.

The plant doesn’t take long to sprout and form roots.

Flowering and Fragrance

  • The green foliage sprouts an abundance of small flowers on dense branches.
  • Aptly named, Scarlet Flax produces red or crimson flowers which are on the smaller side.
  • Typically, these flowers range from ¼” of an inch to 1″ inch.
  • Each flower has 5 petals and is cup-shaped.
  • The red petals are edged in black.
  • At the center of the flower is a red-black eye containing light blue pollen.
  • The plant starts flowering early spring and stays in bloom for the entire season.
  • However, each solitary flower has a short 1-day life cycle but gets replaced by another soon after.
  • The plant also produces small pods containing the seed and breaks open to self-sow.

Light & Temperature

Crimson Flax is pretty hardy and can grow in United States hardiness zones 1 through 10 (USDA Zone).

Even though the plant does extremely well in and loves the full sun, it will grow in light or partial shade.

However, it doesn’t do well in frosty or very cold conditions.

If you live in an area where frost is a problem, don’t sow the Red Flax until the frost has passed.

If you do sow flower seeds in winter areas, make sure they are inside in frost-free conditions and move them out once spring comes.

Watering and Feeding

Like other flowering species, they have low to moderate water needs and are susceptible to damage and root rot from overwatering.

Similarly, the plant also doesn’t do well in rich soil.

It’s better to avoid using fertilizer or manure, it can reduce the plant’s blooming potential.

Soil & Transplanting

As mentioned previously, the Crimson Flax species is very hardy and often drought tolerant.

It grows in any soil type, provided it’s well-draining.

Plant the seeds in sandy soil, loamy or clay soil and it will thrive and flower.

As for transplanting, it’s best avoided as the plant dislikes root disturbance.

It’s better to plant the seeds directly in their permanent location.

If you do sow the seeds in pots, wait for the roots to develop and replant them with extreme caution.

Grooming and Maintenance

As Scarlet Flax is not invasive, drought-resistant, and hardy, it doesn’t require much grooming or maintenance to keep it healthy.

You have to keep the soil moist, watering the plant occasionally.

Prune and cut back the flowering stems in early summer to extend the plant’s bloom time.

Related Reading: Blue Flax (Linum Perenne)

How to Propagate Crimson Flax

Since the plant doesn’t like root disturbance, the best way to propagate Scarlet Flax is with seeds.

Follow these planting instructions:

  • Prepare the planting area by digging up previous growth and flattening out the surface.
  • Wait for the pods to dry on the plant and then break them open to collect seeds.
  • Choose a location getting at least 6 hours of sunlight in the day and after-frost season.
  • Scatter the seeds directly on top of the soil and lightly compress them in.
  • Walk on them or use a board, but avoid burying them deep.

The germination period depends on the weather, soil conditions, etc.

Typically, it would take around 20 to 25 days for the seeds to germinate.

Keep the soil moist, at least until the seedlings as re 4″ – 6″ inches tall.

Afterward, they can survive on natural rains.

However, if you’re expecting a particularly dry season, water them occasionally.

This plant also reseeds freely if you want to go an all-natural route.

NOTE: In the south sow Linum grandiflorum rubrum at any time it makes a good fall-winter bloomer. It is usually sown too thickly, losing the beauty of the individual plant.

Flowering Flax Pest or Disease Problems

Along with being low maintenance, the Scarlet Flax plants are typically disease-free.

As for pests, cutworms and grasshoppers are found occasionally.

We like neem oil or Diatomaceous earth for pest control. Consult a local gardening center for a solution.

The oil-rich seeds are attractive to birds and some insects, but they don’t usually create any problems.

Suggested Uses For Red Flax

The flowering flax species is most commonly used as an ornamental annual plant for its showy, velvety red blooms.

Most people add them as filler in garden beds and meadows. They look great as cut flowers.

The seeds of the red flax are often used for commercial purposes.

The wildflower seeds or red flax seeds are shiny because they have high oil content and are used as a source of linseed oil.

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