Royal Catchfly – (Silene Regia), A Complete Guide


If you’re looking for a showy red perennial that does a great job attracting hummingbirds, then Royal Catchfly is for you! One of the few ‘red’ native prairie plants, it can provide beautiful red blooms from early to mid-Summer and is drought tolerant.

Often considered a rare or endangered plant throughout it’s range due to habitat loss. It still maintains a significant presence in several regions, notably Missouri.

In this article:

What is Royal Catchfly

Royal Catchfly is a perennial flower native to middle America, centered around the Ozark Region of Missouri and Arkansas. Scientifically known as Silene regia, it grows 3-4′ tall in full sun and well drained loamy soil. Blooming for approximately one month in Summer, the dark red blooms stand out and will attract large butterflies and hummingbirds.

The deep throated calyx of Royal Catchfly flowers mean that only insects with a proboscis can pollinate them. This basically means that only butterflies and hummingbirds will obtain the nectar from the flowers. But, other insects that attempt to obtain the nectar such as ants and flies often get ensnared on the stalk, eventually dying. Yet, this seemingly carnivorous behavior is actually just a passive defense against predatory insects that won’t support pollination.

Native Range of Royal Catchfly

The native range of Royal Catchfly is the Midwestern United States, from West Florida to Wisconsin, and West to Eastern Kansas and Oklahoma. The most common range though is Southern Missouri and North Arkansas.

Sources [1] [2] [3]

Royal Catchfly Reference Table

Scientific NameSilene regia
Common Name(s)Royal Catchfly
Native Range, USDA Zone4-9
Bloom TimeJuly-August
Bloom Duration, Color6 weeks
Height3-4′ (60-120 cm)
Spacing / Spread1′-2′ (30-60 cm)
Light RequirementsFull Sun / Partial Shade
Soil TypesSandy-loam to clay loam
MoistureDry to medium moisture
Fauna Associations / Larval HostsLarge butterflies / Hummingbirds
Sources [1] [2]

What are the Benefits of Royal Catchfly

Beauty

If you are partial to red flowers, then Royal Catchfly is a must-have! It produce 10-30 dark red flowers per plant and the blooming period will last for about a month in Summer. Truly a striking appearance in any flowerbed or garden.

Drought Tolerant

Royal Catchfly evolved on the slopes of the Ozark region of prairie and is quite tolerant of drought or mesic soils. It’s tap root allows it to thrive in the hot Summers of the Midwest.

Red Color

If you are partial to red flowers, than this is a must-have! There are not too many native species that produce red blooms. But, you will be treated to beautiful hues of dark, rich red color with this plant.

Hummingbirds!

Royal Catchfly is pollinated almost exclusively by Ruby Throated Hummingbirds. So, if attracting hummingbirds to your yard is one of your goals, then planting several specimens of Royal Catchfly can help you achieve it!

Excuse my poor photography….I was caught off-guard when this hummingbird arrived. But was able to get a few pics with my phone.

Grow and Care for Royal Catchfly

Sunlight Requirements

Royal Catchfly prefers full sun, which is at least six hours of direct sunlight per day. Although it can tolerate partial sun, which is 4-6 hours, the plant will not be as showy or tall.

Soil Requirements

Royal Catchfly isn’t too picky for soil as long as it drains well. It will grow best in soils that contain loam, but sandy-loam or rocky/gravely. The drainage is key though.

I have this plant growing on over-compacted sandy loam that actually behaves like clay soil. But, it is on a slight slope, and apparently it drains enough.

Moisture Requirements

It will grow well in average moist soil to dry soils and slopes. But the main thing to avoid is consistently moist or wet soils.

Did you know? Royal Catchfly has a shorter ‘cousin’ that likes shadier conditions….check out Fire Pink, Silene virginica

Maintenance

Royal Catchfly should require no maintenance except for cutting the plant back to ground in Spring.

Fertilizer

Royal Catchfly does not require supplemental fertilizer. You can add some compost (optional) to the base of the hole when first transplanting.

Yellow Leaves

Near the end of summer, or in particularly hot periods the lower leaves of Royal Catchfly may turn yellow. This can be common in many native plants. Add some supplemental water, and remove the yellow leaves if you prefer.

How to Grow Royal Catchfly from Seed

Royal Catchfly can readily be grown from seed as long as several requirements are met. Seed should either be scarified or cold stratified for approximately 60 days. Also, and this is important! The seed needs exposure to sunlight to break dormancy. [4] [5]

The easiest way to germinate Royal Catchfly seed is to Winter Sow it in January. I’ve germinated dozens of seeds using the following method;

Process to grow and germinate Royal Catchfly seed.

The following steps assume seed has already been cold stratified for 60 days, or is being Winter Sown.

  1. Fill a suitable container with moist potting soil
  2. Press 3-5 Royal Catchfly seeds into the soil. Take care not to cover them as the seed needs exposure to UV light to break dormancy.
  3. Place container in a location that gets morning sun and afternoon shade.
  4. Germination should occur once spring temperatures warm up to around 60-70F during the day.

Although a slow-growing perennial, Royal Catchfly can bloom the first year when grown from seed (I’ve done it). Although you should expect about 3 years for the plant to be full size.

Royal Catchfly Seedlings

Identification and Characteristics of Royal Catchfly

Royal Catchfly will grow to approximately 2-3′ tall when mature. It is known as a slow-growing herbaceous perennial, and can take several years to reach full size when grown from seed.

Prior to blooming it can be difficult to ID, as the overall appearance is generally inconspicuous. But careful examination of the leaves and stalk can make a positive, or likely ID possible.

Stalk

The stalk is unbranched, light green, round in shape, and will be covered in small white hairs.

Leaves and stalk of Royal Catchfly

Leaf

Leaves of Royal Catchfly occur in opposite pairs along the stalk. They are lanceolate in shape, 2″ wide by 4″ long, and light to medium green in color. The margins are smooth and will have tiny white or fuzzy hairs on both sides.

Royal Catchfly emerging in Spring

Flower

Flowers are at the end of short stems near the top of the plant (cymes) with a long tubular calyx that is roughly 1″ long. There are 5 dark red petals that are nearly perpendicular to the calyx axis and the overall diameter is roughly 1″. Blooming lasts for approximately one month beginning in early to Mid-Summer.

Royal Catchfly Bloom, Silene regia

Although flowers are self-fertile they have been found to exhibit a temporary dichogamy to encourage cross pollination with other species. This will allow evolution to proceed, making the plants stronger via natural selection.

Saving Royal Catchfly seed

About one month after blooming, the calyx, which doubles as a seed capsule will begin to turn brown. When this begins to occur the capsules can be harvested. Collect the pods and store in a brown paper bag for a couple weeks in a cool dry place. Then, open the capsules and collect the tiny seeds.

Root

The root of Royal Catchfly is a taproot. Although it is not too prominent. I have successfully transplanted second year plants, and the taproot was quite shallow.

Taproot of Royal Catchfly, Silene regia

Royal Catchfly versus Cardinal Flower

Sometimes Royal Catchfly gets confused with another tall native perennial, Cardinal Flower. While both Royal Catchfly and Cardinal Flower have beautiful dark red blooms and are hummingbird magnets, you are unlikely to find them in the same locations.

Royal Catchfly is more likely to be found in dry open areas, as it is drought tolerant. Conversely you are much more likely to encounter Cardinal Flower along a stream bed or pond edge, as it thrives in moist soil. None the less, the table below should help show the similarities and differences between Royal Catchfly and Cardinal Flower.

SpeciesRoyal CatchflyCardinal Flower
Height2-4′2-4′
Bloom ColorRedRed
Flower characteristic5-petals, daisy likeLarge 3-lobed petal that hangs down
Bloom (click to enlarge)
Leaf arrangementOppositeAlternate
Moisture ConditionsMedium to dryWet to medium moist
Natural HabitatPrairie, slopes, sandy/gravely soilNear streams, ponds, wetland

Wildlife, Pests, and Diseases associated with Royal Catchfly

Pollinators

Ruby Throated Hummingbirds are the primary pollinators of Royal Catchfly. Larger Swallowtail butterflies will also occasionally visit the flower. And the deep calyx means that only those with a proboscis can successfully reach the nectar. So, if you are trying to help bees, you may want to try some other species.

Also, when I say “bees don’t visit it”…I’m not lying. I film my plants a lot, and I can tell you than in long periods of footage I have never recorded any bee visiting Royal Catchfly.

Pests

Almost no insects harm Royal Catchfly. Aphids have been known to suck sap from the stalk. If you notice them, either squish them on the stalk or spray them off with a hose.

Carnivorous behavior

Royal Catchfly has long been thought to be carnivorous. Research done in 2017 has found that Royal Catchfly can capture and retain insects on the Calyx of the flower. But, it is less attractive than commercial glue traps. [6]

Furthermore, the researchers used detailed UV photography to determine that although capture and retention occur, the plant is incapable to secreting digestive enzymes in response (UV photographs showed no difference in surface once capture occurred). This was verified by comparing insects after capture with other carnivorous plants – no digestion was occurring on Silene regia.

Deer and Rabbits

Deer and rabbits tend to leave Royal Catchfly alone. Although one should not take chances with first year seedlings. I strongly recommend you protect young plants or new growth with Liquid Fence. It truly works, and I have used it on my gardens for years. You can find a link to it on our recommended products page.

Toxicity to dogs

It is unknown if Royal Catchfly is toxic to dogs. However, another member of the Silene genus, Silene acaulis is listed as toxic to dogs by the ASPCA. So, it is best play it safe and keep your pets away from Royal Catchfly. [7]

Disease

Royal Catchfly is generally disease resistant. It is an overall tough, hardy plant once established.

Where you can buy Royal Catchfly

Royal Catchfly is not typically sold in nurseries, as it isn’t a typical ‘garden friendly’ plant. But it can be purchased at specialty nurseries that deal in Native Plants. You can find native plant nurseries near you on our interactive map.

Where to buy seeds

We have ordered a variety of native flower seeds from Everwilde Farms, which you can order right from Amazon through our link on our RECOMMENDED PRODUCTS PAGE. (We may earn a small commission when you purchase through our links, at no cost to you. This helps support our website.)

Uses of Royal Catchfly

Garden Uses

A taller perennial, Royal Catchfly can be used in both formal flowerbeds and wildflower meadows, border gardens, and pocket prairies. Plant it close to other ornamental grasses and perennials to give it some support. Shorter spacing will also give the roots competition, forcing the plant to grow ‘up’ rather than out.

Companion Plants

There are numerous companion plants that would grow well with Royal Catchfly. For plants that bloom concurrently and like similar conditions, try Anise Hyssop, Echinacea purpurea, False Sunflower, Liatris Spicata, Wild Bergamot and Mountain Mint. All of these will bring in a variety of pollinators and also blend well.

Medicinal Uses

There are no documented medical or edible uses of this plant.

Find more native plants here

References:

[1] – “Royal Catchfly”. USDA. https://plants.usda.gov/home/plantProfile?symbol=SIRE2

[2] – Wildenberg, Amanda. “Royal Catchfly (Silene regia) Growth and Floral Development in Response to Fertilizer and Photo Period.” (2011). https://digitalcommons.butler.edu/facsch_papers/155/ Accessed 20 May 2022.

[3] – King, Charles C. “DISTRIBUTION OF ROYAL CATCHFLY (SILENE REGIA).” Ohio Biological Survey. College of Biological Sciences. The Ohio State University. 1981 https://www.friendsofeloisebutler.org/pdfdocs/royalcatchflyohio.pdf. Accessed 20 May 2022.
[Flowers self fertile] – Menges, Eric S. “Factors limiting fecundity and germination in small populations of Silene regia (Caryophyllaceae), a rare hummingbird-pollinated prairie forb.” American Midland Naturalist (1995): 242-255. https://www.jstor.org/stable/2426388?seq=1 Accessed 20 May 2022.

[4] – Menges, Eric S. “Seed Germination Percentage Increases with Population Size in a Fragmented Prairie Species.” Conservation Biology, vol. 5, no. 2, 1991, pp. 158–64. JSTOR, http://www.jstor.org/stable/2386189. Accessed 20 May 2022.

[5] – Flocca, Nicolette, et al. “Germination of Silene regia Seeds from Four Sites in Lawrence County, Illinois, Following Scarification or Stratification.” Erigenia (2004). https://works.bepress.com/janice_coons/1/ Accessed 20 May 2022.

[6] – Williams, Amy. “Carnivorous Plants of Ohio.” (1913). https://kb.osu.edu/bitstream/handle/1811/1779/V13N05_097.pdf Accessed 20 May 2022
[carnivorous2 ] -Dienno, Garrett John. An Examination of Possible Carnivory in Silene regia, a Member of the Caryophyllaceae. Diss. Miami University, 2017. Accessed 20 May 2022

[7] – “Toxic and Non-Toxic Plant List – Dogs”. ASPCA. https://www.aspca.org/pet-care/animal-poison-control/dogs-plant-list Accessed 21 May 2022

Joe Foster

Hi - I grew up outdoors in nature - hiking, fishing, hunting. In high school I got my first job at a garden center where I learned to garden and landscape. I've been growing plants from seed and designing native plant gardens for over six years. I hope to share some of my knowledge with you! Additionally I am a wood worker / DIY enthusiast. I enjoy designing/building projects (with hand tools when I can!). I hope to give you some tips and useful information!

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