How to Grow Knautia

Knautia flowers

Jacky Parker Photography / Getty Images

The easy-keeping Knautia (pronounced NOT-ee-ah) isn’t a plant for the meticulous gardener, since it’s tall stems and wide spread mean it can creep into other areas of your garden. However, it features a relatively long blooming season from early summer to fall and produces interesting and beautiful pink to deep-red blooms that resemble a pincushion with green foliage at the base of the plant and up its stem. Part of the scabiosa family, this plant attracts butterflies but is unappealing to deer.

In the right growing conditions, this plant makes an excellent perennial addition to your cutting garden. Harvest the blooms for displaying in your home or adding to bouquets without compromising the plant, since it’s an abundant bloom producer during peak growing season from early summer to fall. 

Botanical Name Knautia macedonica
Common Name Knautia
Plant Type Herbaceous perennial
Mature Size 1 to 3 feet tall and 1 to 2 feet wide
Sun Exposure Full sun
Soil Type Moderately fertile and well-drained
Soil pH Neutral to Alkaline
Bloom Time Summer
Flower Color Pink to Crimson
Hardiness Zones 5 to 9
Native Area Central Europe
Knautia flower blossom up close
Beatrix Jankowski / Getty Images 

How to Grow Knautia

The Knautia has its opinions on growing conditions but is flexible enough to tolerate a variety of conditions—making it a good choice for gardeners of any skill level. This plant loves plenty of sunshine, but high humidity levels will take a toll on the long stems and may also cause root rot. It’s generally resistant to disease, but may be subject to aphid invasion.

Knautia thrives in areas with warm summer temperatures and cool evenings, and it also needs well-drained soil. The blooms don’t last as long as some other flowering plants, but when deadheaded, it will abundantly produce new blossoms for your enjoyment. Its compact but full nature makes it a good choice in a garden bed, but it can also be adapted to container planting. 

Light

This is a sun-loving perennial, so plant Knautia in an area that gets full sun. A wild and free-looking flowering plants, this variety isn’t well-suited towards indoor growing or artificial lighting.

Soil

Drought-tolerant plants like Knautia prefer soil that is well-drained. The soil should be average to dry for this plant to really thrive and to avoid conditions like root rot. As far as pH goes, these plants can tolerate alkaline or acidic soil, though its preferred choice is neutral or alkaline.

Water

Less is more when it comes to watering Knautia. In fact, one of the surefire ways to kill this plant is to water it too often or much. It’s happy in average-to-dry soil, so keep the watering schedule to a minimum to avoid drowning it. Once established, it generally doesn’t need daily watering; check the soil for dryness with your finger in the dirt near the roots. If it’s completely dry, go ahead and water the plant until the moisture reaches a depth of about 2 inches.

Temperature and Humidity

Knautia do well in temperate climates with warm days and cool nights. They’re tolerant to hot weather, but won’t last as long or look as perky. The tall stems of this plant don’t fare particularly well in very high temperatures and humidity levels, such as in the southern parts of the United States. In such a climate, the flower is likely to droop over.

Fertilizer

If your soil is good or average, you likely won’t need to fertilize Knautia. However, if you feel that your soil is severely lacking, a general purpose, time-released fertilizer in early summer will supplement the nutrients found in the ground.

One of the perks of Knautia is that it doesn’t require abundantly fertile soil to thrive. Sandy or relatively infertile soil works just fine for this plant to grow in, and may even cause it to bloom fuller and bushier than it would in very rich soil.

Propagating Knautia

Knautia can be propagated by means of either seed or basal cuttings. The optimal time to do so is in the spring, typically March or April.

To propagate Knautia by seed, surface sow the seeds in a cold frame. For basal propagation in, follow these steps:

  1. Use a sharp pair of scissors to snip off an actively growing stem with a node, close to the base of the plant. There should be one or two leaves on your cutting.
  2. Pot this cutting in moist potting soil and water regularly until new growth becomes apparent. You may also try to root it in water, but the success rate once planted in soil is lower for cuttings rooted in this way.

Varieties of Knautia

  • Knautia arvensis (field scabious): A prolific growing variety, especially in chalky bedrock, the ‘field scabious’ has a lighter pinkish-purple flower.
  • Knautia macedonica: Crimson flowers and green foliage. The ‘mars midget’ variety of this lower classification is popular for its diminutive size and variegated green-and-white foliage.
Knautia arvensis
Knautia arvensis  Rafael_Wiedenmeier / Getty Images
Knautia macedonica
Knautia macedonica Anna Skoog / Getty Images
Knautia in garden
 beekeepx / Getty Images

Pruning

As mentioned earlier, Knautia plants aren’t fussy and won’t require much hands-on pruning throughout the growing season, aside from deadheading faded blooms. However, you may need to stake this plant if it becomes overly tall.

Once the growing season has ended, it’s easiest to prune Knautia in the early winter—after frost has killed the foliage.

Being Grown in Containers

While these plants are a great choice for cottage gardens, they can be grown in containers as well. The key to growing Knautia in a container is to ensure that there is excellent drainage and the soil doesn’t become too boggy. To do so, you may consider a layer of gravel or pebbles in the base of the container to promote drainage.

Growing From Seeds

Knautia grows with relative ease from seed. In the spring, simply sow directly in the ground or in seed starting trays. Once sprouted, harden off the plants and transfer to the garden bed.

These plants are also excellent at self-seeding and will drop seeds that take root and grow with no gardener intervention. If you prefer to keep your Knautia from spreading in this way, the plants are easily uprooted and removed.