Gardeners of all levels love finding beautiful and easy-to-grow species for their gardens. If you’re on the lookout for this type of plant, Linum grandiflorum, or Red Flax, is the perfect contender. This annual herb grows hardily in fields and gardens, producing beautiful, bright red blooms. Here we’ll take you through everything you need to know about growing and caring for Linum Grandiflorum (Red Flax) at home including planting, soil considerations, light preferences, feeding, pruning, and over-winter care.

How to Grow and Care for Linum Grandiflorum (Red Flax)

How to Linum Grandiflorum (Red Flax) – The Essentials: 

Botanical Name:Linum grandiflorum
Also Known As:Red Flax, Scarlet Flax, Crimson Flax
Hardiness Zones:USDA growing zones 1 to 10
Flowering Months: From spring to autumn, depending on location.
Growing Difficulty:Easy. Suitable for beginners.
Type of Plant: Annual herb
Light Requirements:Bright, direct sunlight. Will tolerate partial shade.
Temperature and Humidity:Thrives in temperatures anywhere from 30 to 90 degrees Fahrenheit and most humidity levels. 
Watering Needs:If planted in your garden, Red Flax will likely receive the water it needs from precipitation. Water enough to moisten soil if rainfall is less than one inch per week in your area.
Soil Preferences:Well-draining, slightly moist soil. Can be slightly acidic, neutral, or slightly alkaline.
Feeding:This plant doesn’t enjoy nutrient-rich soil, so there’s no need to fertilize. 
Growth Expectations:Will reach one to two feet tall and six inches to one foot wide.
Toxicity:Non-toxic to humans and pets.

About Linum Grandiflorum (Red Flax)

About Linum Grandiflorum (Red Flax)

Scientific Facts:

Linum Grandiflorum is the species name for Red Flax. This species belongs to the Linaceae family and the Linum genus, also known as the Flax genus. Interestingly, this genus contains around 200 species of plants. 

Origins and History:

Red Flax is native to Algeria. However, it also grows as an introduced species in other areas. Some of these include Northern Africa, parts of North America, and Southern Europe.

Over the years, the world of horticulture has taken note of this plant’s beauty and effortless blooms. In fact, Scarlet Flax has earned the Royal Horticultural Society’s Award of Garden Merit. 

Botanical Characteristics:

Botanical Characteristics

While there are hundreds of Flax species, you can tell Scarlet Flax by its bright red color. The plant’s flowers have five petals that grow in delicate, circular blooms.

This species has a clustered growth habit and branches that develop long, green foliage. Its flowers each have a dark center, dark edges, and upright stamens that produce blue pollen.

Uses and Benefits

Linum grandiflorum will invite pollinators like bees and butterflies to your garden. It is most often grown to fill gardens as an ornamental species. These plants are also beneficial to gardeners who use Flax plants to make products like linseed oil and linen material for clothing. 

In the language of flowers, flax traditionally symbolizes wisdom, creativity, and righteousness. 

Bloom Time and Flowering Season

Bloom Time and Flowering Season

Red Flax blooms starting around late spring. The plant will continue producing new blooms until autumn. This plant’s flowers only last for a few hours, but new blooms open quickly as others fall away.

Growth Expectations

Red Flax plant will typically reach one to two feet in height and six inches to one foot in width. It will take one to two years for this species to reach its mature size. 

Best Companion Plants in the Garden 

Red Flax looks beautiful when paired with plants that highlight its bright blooms. Here are a few companion plants to consider for Linum grandiflorum.

How to Grow Linum Grandiflorum (Red Flax)

How to Grow Linum Grandiflorum (Red Flax)

Best Locations to Plant Red Flax

The best locations to grow Red Flax is in garden beds or open fields and meadows. Make sure to plant it in a spot that gets plenty of full sun throughout the day.

What Are the Best Times of Year to Plant Linum Grandiflorum? 

The best time of year to plant Crimson Flax will depend on when you want its flowers to bloom. For earlier blooms, you can sow seeds during the fall. Plant seeds in early spring for blooms in the summer months. 

Growing from Seed vs. Planting Young Nursery Plants

Growing from Seed vs. Planting Young Nursery Plants

It’s best to grow Linum grandiflorum from seed, as they can be tricky to transplant. This is because the plant has delicate roots that are easily damaged during the transplanting process. 

Starting Red Flax in your garden is easy, but it’s possible to relocate seedlings if needed. Some gardeners start this species in peat pots indoors. This can facilitate an easy transfer and secure earlier blooms. 

What to Do Before Planting 

Before you plant Scarlet Flax, find a spot in your garden that receives plenty of direct sunlight. Make sure you have enough space to plant the seeds around six inches apart. 

Now, grab the tools you will need to plant this species, like a garden spade or hoe, scissors, or insecticide. Check the Essential Tools section below for a list of everything you need to plant Linum grandiflorum seeds. 

What’s the Best Soil for Red Flax

What's the Best Soil for Red Flax

Your Crimson Flax plant will love a well-draining, slightly moist soil. The plant doesn’t require a specific pH level. It can handle environments that range from slightly alkaline to slightly acidic. 

However, one thing Flax plants are particular about is soil fertility. Interestingly, Red Flax will bloom best in soil with a low fertility level.

How to Plant Red Flax

Now, it’s finally time to plant your Crimson Flax. Here are a few steps to take when sowing Linum grandiflorum seeds in your garden. 

  • Get soil ready by removing any weeds and raking the top layer of soil. You can use a gardening hoe or spade to loosen up the top six inches. 
  • Scatter seeds on the soil’s surface around six inches from one another. Press them gently into the soil without covering completely.
  • Water the area, and be sure to keep it moist for a few weeks until seeds begin to germinate. 
  • If transplanting, do so before these new plants have fully developed root systems. 

Light Preferences

Light Preferences

Red Flax thrives in bright, direct sunlight. However, the species will also tolerate partial shade if necessary. 

Temperature and Humidity Preferences 

Fortunately, Red Flax’s hardy nature means it can endure temperatures from 30 to 90 degrees Fahrenheit. It is not particular about humidity levels and is tolerant of drought conditions. 

How to Care for Linum Grandiflorum (Red Flax)

How to Care for Linum Grandiflorum (Red Flax)

Watering Red Flax

Red Flax is an easy plant to care for in every sense, and its watering schedule is no exception. Typically, the species receives all of the hydration it needs from precipitation. 

The only time you’ll want to consider occasional watering is if rainfall is below an average of one inch per week in this plant’s environment. 

How, When, and Why to Fertilize 

Remember, Flax plants grow best in low-fertility soil. This means fertilization is usually unnecessary for this plant. If you think your Red Flax is suffering from poor soil quality, you can apply a low dose of diluted fertilizer.

Pruning and Cutting Back

Pruning and Cutting Back

You may prune withered foliage and flowers on Linum grandiflorum any time throughout the year. Use clippers to cut back these areas and create a tidier appearance. Just be sure not to cut areas where any new growth is forming. 


The best way to propagate Red Flax is by seed. Simply wait for seeds to dry on the plant and collect them to create new Linum grandiflorum plants.

Another great thing about this plant is that it will self-sow its seeds. This means that if you’re looking to produce more Red Flax, the plant will naturally reproduce itself without any work on your part. 



Like other Linum varieties, Crimson Flax is tolerant of cold conditions. So, this plant won’t typically need special care for overwintering.

When and How to Transplant Red Flax

It is usually easier to plant Red Flax seeds directly in the ground. Still, many gardeners choose to start them in containers and transplant them later. Be mindful of the plant’s root system if you take this approach, as it won’t handle damage well. 

You can also start this plant in small peat pots to make the transplanting process easier. Follow the steps in the How to Plant section when transplanting your Red Flax seedlings.

Deadheading Red Flax

It is not necessary to deadhead your Crimson Flax plant. However, if you prefer a tidier look, you can trim away any old and withered foliage after the plant’s growing season has ended. 

Common Problems and How to Treat Them

Common Problems and How to Treat Them

Signs of Watering Issues

Drought-hardy Red Flax likely receives plenty of hydration from precipitation. However, sitting in a soggy environment may cause this plant to develop fungal root rot. 

If you notice signs of root rot, remove the affected area with care. Replace any infected areas with a fresh, clean soil mix. 

Signs Red Flax is Getting Too Little Light

If your Red Flax receives too little light, it may not produce its best blooms. The best way to prevent this is by making sure you plant seeds in a location that receives plenty of bright, direct sunlight. 

Common Pests and Diseases 

Now, you will need to watch for a few garden diseases and pests to keep your Linum grandiflorum growing happily. Here are a few of the common issues that may come up with this species. 

  • Aphids
  • Flax bollworm
  • Cutworms
  • Rust
  • Rhizoctonia
  • Fusarium wilt

If you notice pests infesting your Red Flax, remove visible insects manually. Treat the plant with an insecticide until the issue subsides. Applying diatomaceous earth will help with cutworm issues. 

Fungal issues like rust, fusarium wilt, and Rhizoctonia need to be addressed immediately. Remove any affected soil and plants, and avoid planting new plants in the infected soil. 

Essential Tools to Have Around 

Essential Tools to Have Around

Here is the full list of tools and materials that you will need to grow and care for your Linum grandiflorum plants. 

  • Scissors
  • Well-draining soil
  • A gardening spade or hoe
  • Diluted fertilizer, only if the soil is particularly poor
  • Insecticide
  • Diatomaceous earth
  • Container for storing harvested seeds

Wrapping Up 

With showy blooms and minimal care needs, Scarlet Flax is sure to make gardening a joy. 

Keep its care requirements in mind, and this plant will reward you with plenty of growth and color. Now that you’re ready to grow Linum grandiflorum, it’s time to head out and get digging!

Flax Flower Growing and Care Guides:

For more, see our comprehensive guide to growing Linum Lewsii (Lewis Flax) at home.

Growing Linum Grandiflorum (Red Flax) FAQs

Linum grandiflorum can reach between one and two feet tall and six inches to one foot wide when it reaches maturity.

Yes, Linum grandiflorum self-seeds.

Linum grandiflorum is tolerant of low temperatures. However, if your area is prone to frost, avoid planting Red Flax seeds until spring.

No, Linum grandiflorum is an annual plant.

Yes, Linum grandiflorum is tolerant of partial shade. However, it will grow best in direct sunlight.

No, Linum grandiflorum is not poisonous to humans.

Contributing Editor | Full Bio | + posts

Brandy Wells is an American copywriter and content writer living in Spain. From hiking in her hometown near the Smoky Mountains to digging in the dirt in rural Oregon, she has always put a love of nature at the heart of her endeavors. These days, you’ll catch her writing content, and of course, taking breaks to tend to her growing houseplant collection.

Author Brandy Wells

Brandy Wells is an American copywriter and content writer living in Spain. From hiking in her hometown near the Smoky Mountains to digging in the dirt in rural Oregon, she has always put a love of nature at the heart of her endeavors. These days, you’ll catch her writing content, and of course, taking breaks to tend to her growing houseplant collection.

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