How to Plant, Grow, and Care For Astrantia

Astrantia, also known as masterwort, is a group of showy plants with long-lasting papery bracts that make excellent fresh-cut flowers and dried flowers. You certainly don’t have to cut them to enjoy them, however. Astrantias make fabulous garden plants. They add charm to your cottage garden and a dash of color to your shade garden. Or place them along a perennial border and enjoy their beauty anytime.

These plants make an excellent filler for edges, borders, and corners. They are compact, with a low to medium height. Their neat clumps will slowly expand over time to fill in their available space without becoming aggressive or invasive. Their unusual flowers add both subtle charm and character to your flower garden, politely complimenting their neighboring plants.

No matter where in your landscape you decide to grow astrantia, they are sure to be a pleasure. These plants are easy to grow and low maintenance. You’ll need a relatively moderate to cool climate, however, as they don’t like heat and humidity. Otherwise, place them in a location with partial shade and rich, moist, well-drained soil. 

Do you have just the spot for a showy and well-behaved perennial flower? Let’s dig right in to learn more about astrantia and how you can help these plants thrive in your home garden.

Plant Natural History

Astrantia is a member of the carrot family (Apiaceae) that’s native to Europe and western Asia. In its native habitat, astrantia grows in fields, meadows, and grasslands. It is also found in open woodlands and along streamsides because of its affinity for moist soil.

Astrantia is a genus with at least six different species. Astrantia major is the most widely cultivated and is commonly available in the nursery and garden trade. Astrantias have a long history of cultivation and have been bred into numerous showy cultivars. Astrantia is also commonly known as masterwort.

Characteristics

Astrantia is an herbaceous perennial flower that grows two to three feet tall. These mounding plants form attractive rounded clumps. Within a few years of growth, your plants will start to spread by self-seeding and root stolons. They form colonies but are not considered invasive because it’s easy to control any unwanted spread.

Astrantia leaves are palmate and typically have five deeply cut lobes. The number of lobes per leaf ranges from three to seven, and each lobe is toothed along the edge. The leaves typically remain dark green throughout the growing season, then turn brown in the fall and go dormant until the following spring.

The flowers of astrantia are naturally greenish-white, although the cultivars display a variety of showy colors in the pink and purple range. At the outer edge of each inflorescence are stiff, papery bracts. At the center of the inflorescence is a pincushion-like formation of a cluster of tiny flowers. The larger papery bracts completely surround the internal mass of tiny flowers. Astrantia blooms anytime from late spring into fall, depending on the local climate conditions.

Propagation

You can easily propagate your astrantia plant by seed and division of established plants. Since seeds collected from cultivars and hybrids generally don’t grow true to the parent plant, and some varieties may be infertile, you’ll have the most consistent results propagating your plants by division.

Seed

Some varieties of astrantia are easily grown from seed with a bit of advance preparation. Astrantia seeds need to be cold-stratified for at least eight weeks before they will germinate properly. You can either sow them directly outside in the fall and allow them to overwinter in natural conditions or store them in your freezer for a couple of months and sow them outside in the spring. 

After a period of winter cold stratification, you’ll need to keep the seeds moist until they germinate. When the weather starts to warm in the spring, make note of the patch where you planted your astrantia seeds and water it regularly to keep the seeds and soil surface moist. The germinating seeds and young seedlings are very sensitive to drying out.

As your young seedlings grow and develop, thin them to approximate one plant per square foot. You can carefully dig and transplant any of these seedlings to new locations or transfer them to individual pots and pass them along to a gardening friend or neighbor.

Division

If you already have a mature clump of astrantia, the quickest and easiest way to propagate your plants is by division. Divide your plants in early spring or late fall for best results. Use a sharp spade to dig out a section of roots and stems from a mature clump.

Then, simply transplant the divided cluster to a new location. Fill in any gaps around the roots with fresh soil. Then, water your new plants well to help them recover from transplanting shock.

Transplanting

Whether you are dividing old plants or buying new plants from the garden center, the transplanting method is the same. If you can, time your transplanting for a cool spring or fall day to help minimize stress to your plant. 

Select an ideal site to match astrantia’s preferred growing conditions and prepare a hole for transplanting. Dig the hole just a little bit larger than the pot in which your plant is currently growing. Now is the time to add any soil conditioners, such as organic compost or enriched soil to help improve the soil. 

Carefully remove your astrantia from its pot and transfer it into the hole. Match the current soil level from the pot to the new site and fill in around the roots of your plant with fresh soil. When your plant is settled in its new home, give it a deep watering to help it settle in, and then keep it well-watered for the first week or so.

How to Grow

In favorable climate conditions, astrantia is easy to grow. You will need a mild climate with a partially shaded location and rich, moist soil. 

Sunlight

Astrantia likes a lightly shaded location with dappled sunlight or morning sun followed by afternoon shade.  If grown in full sun, they are likely to burn and dry out. If grown in full shade, they will tend not to bloom. Two to four hours of morning sunlight is ideal.

Water

These plants require moist soil. As long as your soil retains moisture and your area receives regular rainfall, you shouldn’t need to provide extra watering. Astrantia doesn’t like dry soil, however, so if you aren’t getting regular rainfall, go ahead and water your plants to help keep their roots moist. They can even tolerate occasional standing water.

Soil

The ideal soil for growing astrantia is organically rich. If your soil isn’t naturally high in organic matter, add some organic compost at the time of planting and work this into your garden area before transplanting. The soil should also be consistently moist and well-drained. 

Climate and Temperature

Astrantia grows well in USDA Plant Hardiness Zones 4 – 7. It prefers cooler climates with cool summers and does not perform well in long, hot, humid summers. It should grow well in most of the northern United States.

Fertilizing

If your soil is naturally rich and high in organic matter, you may not need to add any extra fertilizer. If your plants are looking yellowed, sluggish, and not growing well, or if you have poor-quality soil, apply a light dose of fertilizer in early spring and again in mid-summer. 

Maintenance

A healthy astrantia is a low-maintenance plant. It appreciates the same good garden maintenance practices that will benefit your entire landscape. Keep your garden free of weeds, check regularly for pests and diseases, and remove dead vegetation each winter. You can add mulch around the roots to help maintain soil moisture.

Garden Design

Astrantia is a very rewarding garden plant that can be used in a variety of landscape designs. Since these plants benefit from a bit of shade, combine them with other shade-loving perennials such as hostas, ferns, and astilbe. 

Use it in perennial flower beds, cottage gardens, and along a woodland edge. Place them front and center in your landscape design where they can be seen and appreciated. They make especially attractive plants to include in a showy perennial flower border.

Varieties

There are a great number of spectacular astrantia cultivars. The plants themselves have similar forms but you will find great variation in the shades of pink, purple, magenta, scarlet, and white flowers.

‘Abbey Road’

The ‘Abbey Road’ cultivar displays vigorous growth and is noted to be a bit more tolerant of dry soil conditions than many other astrantias. Its deep violet-pink flowers develop on tall stems and are excellent for cutting.

‘Alba’

This astrantia has beautiful white flowers. The ‘Alba’ flowers are large and primarily white, with green-tipped outer bracts, giving them a slightly bi-colored appearance. ‘Alba’ is readily available in the greenhouse market and would be an excellent plant to complement any other variety.

‘Claret’

‘Claret’ has strikingly beautiful dark burgundy red flowers on long dark-colored stems. Compared with other varieties, ‘Claret’ has some of the darkest, boldest flower color. This cultivar makes excellent cut and dried flowers.

‘Roma’

‘Roma’ is a cultivar with beautiful reddish-pink flowers. The bracts darken from very pale pink at the center to darker rose at the tips. The antique rose coloration gives these flowers a look of fine delicacy, although they are actually quite sturdy. 

‘Star of Beauty’

‘Star of Beauty’ has a definite WOW appeal. The bright pinkish-purple bracts have scarlet to magenta-colored central flowers. The bright and bold colors on these blooms are sure to attract plenty of attention!

Common Problems

Astrantia is a generally trouble-free plant. You may occasionally see aphids or slugs feeding on your plants, although these pests rarely cause major damage. 

Aphids

Aphids are small, soft-bodied insects that feed on plant juices. They may appear green, yellow, gray, white, or even pink. Aphids typically cluster in large numbers along plant stems and along the veins on the undersides of the leaves. Although aphids are small, you can clearly see them. 

If you have large infestations of aphids, you will see the insects themselves. You may also spot the sticky ‘honeydew’ residue that they leave behind while feeding. The honeydew attracts both ants and fungal infections. If aphids feed long enough, you’ll notice your plants may look weak, yellow, or wilting. 

A few aphids on the leaves of your plants won’t cause any significant damage. Beneficial insects, such as ladybugs and lacewings love to eat aphids. You can safely remove aphids by spraying them with a strong spray of water from your hose. Large and bothersome infestations can be controlled by using insecticidal soap, but be aware that this will harm beneficial insects as well. 

Slugs

Slugs are common garden pests that typically come out to feed at night. These shell-less mollusks feed on tender green leaves, fruits, vegetables, and decaying vegetation. They hide under leaves, rocks, and logs during the day.

Even though you may never see the slugs that are eating your plants, you’ll see the evidence they leave behind. Slugs will eat smooth-edged holes in the leaves of plants. You can tell slugs are around because you will also see their telltale shiny slime trails whenever they come out of hiding.

Slugs can be difficult to control. One of the first things to do is remove their favorite hiding places, such as unused containers, boards, and flat stones. You can also discourage slugs by creating good air circulation around your plants. Set out flat boards to lure slugs and then remove them each morning. You can also try beer traps to effectively remove slugs from your garden area.