How to Plant, Grow, and Care for Knautia

Knautia macedonica, aka knautia (pronounced “naughty-ah”) is a relative of scabiosa and produces domed, purplish-red flowers in the garden. In fact, it’s a close enough relative of scabiosa that it was previously named Scabiosa rumelica. Like scabiosas, knautia is deer-resistant! 

Knautia is known for its long blooming time, which begins in early summer and into the fall until the first average frost date. Its flowers are not only pleasing to the eye, but they are also attractive to a variety of pollinators, including butterflies, hummingbirds, and bees! The flowers also deserve a prized position in your cut flower bouquets. 

Find a full sun area in your garden, water regularly until established and Knautia macedonica will thrive! This is a great starter perennial for most beginner gardeners. It’s easy to care for, with few pests/diseases and is generally a great choice. They aren’t as long-lived as other perennials, but despite that, they’re well suited to amateurs’ full-sun cottage gardens, and readily self-seed for years to come. 

The only real drawback is in extremely hot climates, it may stop producing flowers during the peak summer heat. Outside of this, if you promptly remove spent flowers, you can encourage an additional bloom. At the end of the growing season, leave the last round of spent flowers standing as a wintertime snack for the birds who love these seeds! It makes a lovely and attractive natural feeder for birds.

What is Knautia?

Knautia come in many different varieties and species, such as Knautia macedonica, K. arvensis, and K. drymeia just to name a few. We’ll be focusing on the Knautia macedonica since it is the most common and widely available in garden centers. Its common names include widow flower, field scabious, and pincushion flowers. 

Native Area

Also known as Macedonian scabious, knautia grows as a native in Southeastern Europe, including North Macedonia, Bulgaria, Greece, Romania, and Turkey. Knautia macedonica is a short-lived perennial, usually lasting between two to three years. Although individual perennials don’t last for many growing seasons they will generously self-seed and new ones will spring up year after year. 

Characteristics

Some varieties of the knautia, such as ‘Thunder and Lightning’, have variegated foliage which makes them stand out in the garden. Most varieties feature domed flower heads that sit atop slender, branching stems and deep green foliage at the base. The flowers bloom from early summer through fall, bringing in butterflies and moths.

The tall stems topped by small pincushion flowers sway in the wind and attract many beneficial pollinators. Knautia grows in clumps and will die back completely in the winter, and come back to life in the spring to bloom again in early summer. It is extremely hardy and can survive temperatures as low as -4°F (-20°C). 

Varieties

There are many types of knautia you can grow in your garden to bring in butterflies and other pollinators! Although we will be focusing on the Knautia macedonica here, there are a few species that are also worth mentioning! All of these varieties have similar growth habits. 

Knautia arvensis, also known as the meadow widow flower, blooms in mid-summer rather than early summer, between July and September, and is used by marsh fritillary butterflies and the narrow-bordered bee hawk moth as a food source. This species of scabious was used to treat scabies and other sores, including those caused by the bubonic plague. 

Knautia drymeia, also known as the Hungarian widow flower, is a European species that prefers a southern temperate climate and can be found growing along the edges of various forests and meadows. It blooms in early summer, from June to September.

Finally, let’s examine Knautia macedonica ‘Thunder and Lightning’. This knautia has attractive blossoms that are deep fuchsia. Its foliage is also quite attractive, donning serrated green leaves with cream margins. The shape of the leaf margins gives onlookers a sense of lightning strikes. The average bloom time of this knautia is from early summer to early fall.

Planting

Start by selecting a location with full sun and well-drained soil. Dig a hole about twice the width of the root ball and eight to ten inches deep, ensuring the hole is large enough to accommodate the roots comfortably.

Space multiples 12-15 inches apart to allow for good air circulation and prevent overcrowding as they grow. Add compost to the soil at the planting stage and place in the hole, ensuring the crown is level with the soil. Backfill with soil, gently pressing to remove air pockets.

Water thoroughly after planting and keep the soil moist but not soggy until the plant establishes itself. Mulch around the base with a two-inch layer of organic material to retain moisture and keep the weeds down.

How to Grow

Knautia macedonica is very low maintenance and long-blooming once established in the garden. It’s drought-tolerant and attracts a variety of pollinators such as butterflies and hummingbirds. Read on to find out what to expect when caring for this attractive specimen. 

Light

Knautia grows best in full sun, so select an area in your garden that receives at least six to eight hours of full sun daily. Given optimum conditions, knautia will come back each year. It is however, a short-lived perennial that generally lasts two to three years. However, it will self-seed and spread if given a chance. 

Water

Water regularly for the first year after planting to help them get established. During the peak growing season (summer) water twice a week and once per week during the shoulder seasons (spring and fall). Reduce to once per week in peak season during year two and once every one to two weeks in year three. 

It can also benefit from winter watering in especially dry areas that don’t receive regular snowfall. Water during the winter only if the air and soil temps are above 40°F (4°C), the soil isn’t frozen, and there is no snow on the ground or in the immediate forecast. Mulch will also keep the roots safe in cold weather. 

They prefer deep and infrequent watering and can stand to dry out between watering. A layer of mulch around base can help retain moisture around the roots for longer. This is especially important in areas with low humidity which is where they tend to thrive naturally. Their low water needs make them an excellent choice for the water-wise garden, and are considered to be drought-tolerant once established. 

Soil

Knautia prefers dry and more alkaline soils, although it is tolerant of most soil types. The most important factor here is that the soil is well-draining. Although, as mentioned above, Knautia can benefit from a layer of mulch to help the soil retain moisture, it is important that the soil drains well and does not promote standing watering. 

Amend heavy clay soil with compost and perlite to help improve its drainage. Avoid planting in low-lying areas in your garden or near downspouts where water may collect. When you spread mulch, don’t apply so much that it chokes it, preventing blooms that are attractive to butterflies and forage for birds.

Temperature

The plant thrives in USDA growing zones 5-9 with an ideal temperature range between 65-80°F (18-27°C). Knautia macedonica seems to prefer garden climates that include warm summer days with lots of sun and cool summer nights. 

Although it loves full sun, in the heat of the summer, it may seem to droop and may not bloom as much, diverting butterflies to other areas of the garden. In the winter, it will die back almost completely to the ground but will come back to life as the soil warms in the spring. They require no protection from the cold when grown in zones 5-9. 

In more northern zones, grow as annuals or overwintered as perennials with protection like burlap bags, a cold frame, frost blanket, and a little bit of luck. Above growing zone 9 tends to get too hot for knautia, and although they can survive in light shade, they may not flower as much.

Fertilizing

If you have good to average soil, you shouldn’t need to fertilize knautia. They are light feeders and can do fine with a side dressing of compost at the beginning of each season. If you choose to fertilize knautia, use a balanced product and apply it according to the manufacturer’s directions. 

Avoid using a fertilizer high in nitrogen, as this will promote foliage growth at the expense of producing attractive flowers.

Maintenance

Knautia can benefit from pruning in early or late winter after the foliage has died back and the blooms have faded, but this isn’t absolutely necessary. It can be left in place until spring and pruned just before new growth appears. Leaving the dead foliage standing over the winter can provide it with extra protection, and the standing seed heads will provide birds with winter snacks. 

If you wish to control the spread of your knautia, you may choose to deadhead the spent blooms in early fall after the last flowers have faded to prevent further germination of seeds. Knautia is very good at self-seeding and can spread if left unchecked, though it is not considered one of those invasive perennials. 

Like most flowering perennials, knautia can benefit from deadheading throughout the growing season to encourage more attractive flowers that butterflies love. This also gives them an opportunity to be utilized as cut flowers. As always, prune away dead or diseased foliage as needed. 

Knautia macedonica can be grown in containers and pots. However, the main challenge is ensuring that the potting soil does not become too saturated with moisture. Add perlite to a standard potting soil to create a well-draining potting mix. 

Since knautia is a short-lived perennial, you can avoid having to re-pot it by planting it in an appropriate-sized container in the first place. Follow the planting directions provided by the garden center from which you’ve purchased your knautia. Then, place your repotted containers in areas where you want to keep out deer.

Propagation

Knautia macedonica can be propagated by seed in pots in a cold frame. These seeds require a period of cold stratification to germinate. They must be exposed to temperatures of 39°F (4°C) for at least four weeks before sowing. Placing the seeds in a cold frame any time between February and April is a low-maintenance way to achieve this. 

The seeds can also be left after they first bloom in June or July to drop to the ground on their own in the fall, but this is not ideal if you want to spread to other areas of your garden more intentionally. They can also be propagated by taking basal cuttings in the spring. Place the basal cuttings into a glass of water, and the roots will appear after a few weeks. 

Once measurable root growth has appeared, place the cutting into the soil and water a few times a week until established. Plant them out well before they are in full bloom in July, preferably as part of your spring planting. 

Common Problems

Knautia macedonica is fast-growing and requires little maintenance. That being said, there are some issues to be on the lookout for. Understanding these perennials can help you provide your plants with optimum conditions, which in turn will help them produce more flowers. 

Growing Problems

Most growing problems when you grow knautia in poorly draining soil. If the growth seems stunted or is wilting outside of full sun or the heat of the day, this can indicate that the roots are sitting in standing water due to poorly drained soil. 

If you grow knautia in a pot or container, you may repot it into a potting soil mix with better drainage. For knautias that have been planted directly into the ground, choose to amend the soil by adding sandy soil to increase drainage. 

If a nearby downspout causes the standing water or if this is a low-lying area in your garden, then your best bet is probably to dig it up and grow in another location.

Knautia that flower in July, feed butterflies, and then drop to the ground for self-propagation and future attractive long-blooming, it’s possible that birds could eat the seeds before they have time to germinate and return in spring. If this is an issue, remove the seed heads yourself after the long blooming period and sow them after cold-stratifying them indoors.   

Pests

Knautia is known for being deer-resistant, an attractant for pollinators, and specifically draws in hummingbirds and butterflies. It is generally pest-resistant. However, it has been known to have occasional issues with aphids. Blast them off with a strong spray from a hose. 

In more advanced infestations, neem oil can be used to control them. Providing diverse habitats for predatory bugs like ladybugs, the praying mantis, paper wasps, etc, will help keep these pests in check. 

Diseases

Not only is Knautia macedonica deer-resistant, but it is also generally disease-free and does not suffer from any major issues. 

Frequently Asked Questions