Pick the Right Potentilla! Growing Cinquefoil from Seed
Sep 25, 2018
"Hold my beer! I'm going online to find out about cinquefoil plants," you said about six hours ago. And now you're here, utterly confused by all the conflicting information about names, origins, and growing conditions. Heck, you might have even forgotten your own name by now. And you definitely want that beer back.
We've been keeping an eye on other cinquefoil seed retailers and gardening websites to see how they present plant varieties in the potentilla genus, and we feel your pain. There is a lot of confusing—if not downright conflicting—information out there, in part because there are many widely-accepted common and botanical names for many of the most popular varieties.
We're going to simplify things just a little.
Getting the Names Straight
Cinquefoil is often used as a generic term to describe members of the potentilla genus. Conversely, potentilla is a common name often used to market these same plants.
If you walk into a reputable garden center and ask for either "cinquefoil" or "potentilla", your seasoned nursery operator will wait patiently for you to get more specific. A seasonal worker punching the clock to get out of his parents' basement for a few hours each day might send you home with a young shrub that will eventually grow several feet in each direction, blossoming with charming yellow flowers, when what you wanted was a mounded, sprawling rock garden specimen with dramatic deep red blooms.
Trust us. If you stick Potentilla fruticosa or other large plants called "cinquefoil" among your dainty Hidcote English lavenders or in the foreground of your patio garden, you're going to be really pissed in about a year or two...yet at least one of the leading gardening sites suggests you do just that.
There are Potentilla species native (or adapted) to almost every continent and climate in the world, each having its own cultural value.
Potentilla derives from potens, the Latin term for (you guessed it) potent. This is in reference to a few varieties known for their medicinal properties. They're high in tannin, which makes some potentillas useful as an astringent.
"Cinque" is from the Latin root word meaning "five," and "foil" is an old English word for leaf. Thus the common name applied willy-nilly to members of the Potentilla genus, which itself is a member of the Rosaceae (rose) family. There are two general types of potentilla: Large, round, dense shrubs, and low-growing, clumping, or spreading plants with flowering upright stems. All tend to have blooms resembling colorful strawberry blossoms (or, more appropriately, wild rose flowers) and palmate leaves with 3 to 7 (typically 5) lobes.
Potentillas are herbaceous perennials, usually with woody stems. They're particularly hardy and deer-resistant, and they're a great choice for gardeners who want a low-maintenance, long-blooming landscape plant.
According to Alternative Nature Online Herbal, some varieties of cinquefoil were ingredients in Medieval magic spells and love potions:
In an old recipe called 'Witches' ointment' the juice of five-leaf grass, smallage (wild celery) and wolfsbane is mixed with the fat of children dug up from their graves and added to fine wheat flour.
We added the bold italics for emphasis because this pretty much takes the cake (no pun intended) for wackadoodle herbal remedies. Maybe this recipe inspired the fairy tale Hansel and Gretel? Anyway...five-leaf grass is one of many nicknames for cinquefoil...and wolfsbane (Aconitum napellus) isn't something you want to mess with. It's highly toxic.
Potentilla, on the other hand, is deemed pet-safe by the ASPCA. Searches on Poison.org for potentilla and cinquefoil didn't produce any results, which is a good sign in our book. Still, take the usual precautions.
Spotlighting Potentilla thurberi for the Sake of Sanity
We're going to focus on the more compact, sprawling variety today, specifically one of the species that's most popular among home gardeners: Potentilla thurberi. From here on out, if you read "cinquefoil," it's purely to boost our SEO. Not just for our own rankings, but to rescue all those poor souls Googling their heads off while trying to get the straight dope. You know...like yourself.
P. thurberi has its own aliases:
- Scarlet cinquefoil
- Thurber's cinquefoil
- Red cinquefoil
- Monarch's velvet
The plant's specific name is for George Thurber, (1821-1890) who, according to Northern Arizona University's Katherine Sides (Go Jacks!) "was a botanist with the U.S. Boundary Commission from 1850 to 1854 and editor of the American Agriculturist for 22 years."
Its blooms are magenta to deep red in color, and its five petals have a matte, velvety appearance. The flowers form a slightly cupped shape, and the flower head is about 2" in diameter. Usually, Potentilla thurberi flowers are dramatically darker in the center, fading out toward the edges, with contrasting and highly-visible yellow anthers.
Potentilla thurberi's dense basal leaves are palm-shaped, with five to seven serrated lobes. They're medium to dark green, with a slight sheen. The plant's stems are at least a foot long covered in smaller leaves and clusters of flowers.
P. thurberi and its close relatives (those with similar growth habits, at least) look great in out-of-the-way corners of your rock garden or planted on the edges of natural stone retaining walls. If you've got a mountain getaway, these perennials will hold their own when you're not around and don't need fencing from deer, elk, or snowshoe hares.
You don't have to live in the mountainous Four Corners area to plant P. thurberi (or other high-altitude cinquefoils). Just follow the basic care guidelines, and you're good to go.
Cinquefoil in the Garden
P. thurberi, our "example plant," is native to elevations between 6000' and 9000' in Arizona and New Mexico's mountain forests, where it grows near (but not in) natural water sources such as springs, lakes, and streams. These areas are semi-arid and rocky, and as with all climates at altitude, they're exposed to more UV rays. Therefore, this species really does prefer full sunlight, but it likely optimizes the available light that filters through forest canopies.
USDA Hardiness Zones: Perennial in zones 5 to 9.
Sunlight Preferences: Full sun to partial shade; some sources say Potentilla thurberi tolerates full shade but we think those people are messing with us, or just confusing this plant with another species.
Moisture Requirements: Somewhat drought tolerant once established, P. thurberi shouldn't be allowed to dry out in its first year. Plant it in a location where it will receive intermittent deep watering when it's mature.
Soil Preferences: Medium quality well-drained soils.
pH: 5 to 7.5.
Plant Height: 1" to 3" (much of the height being attributed to the long flowering stems).
Plant Width: 1" to 2.5".
Growth Habit: Clumping, with a tendency to spread.
Bloom Period: June through August, possibly up until the first frost.
Maturity: P. thurberi and many other cinquefoils often don't bloom until their second year, instead spending their energy establishing their root system.
Pests & Diseases: No known susceptibility to pests or diseases. Prevent crown rot by keeping mulch away from the plant's base.
Maintenance: Deadhead spent flowers to prolong blooming.
Harvesting: Cinquefoil's beauty is limited to your landscape. It doesn't make a very good cut flower. If you decide to find a potentilla species known for its medicinal properties, be sure to find out if you need the roots, flowers, leaves, or stems, and follow the recommendations specific to that plant. And...cross-reference your sources. Although potentillas are generally deemed non-toxic, you're better safe than sorry.
Growing Cinquefoil from Seed
Seed Treatment: P. thurberi is native to higher-altitude environments. Its seeds are adapted to cold winters and the thaw/frost cycle that often helps break the outer protective layers. We recommend about 30 days of cold stratification to help boost your cinquefoil seed germination.
When to Plant Outdoors: Direct sow your cinquefoil seeds after your last spring frost, when the soil temperatures have reached 65°F.
When to Plant Indoors: Start your seeds inside under grow lights at least 6 to 8 weeks before your last frost.
Seed Depth: No more than 1/16".
Seed Spacing: Plant or thin 16" to 24" apart.
Days to Germination: 14 to 21 days under optimal conditions.
Transplanting Tips: Cinquefoil, like many woody perennials, takes a little more time to get established. Many commercial growers will "nurse" their starts in larger containers until late summer, transplanting their cinquefoil in early fall.
Why Get Your Seeds from Seed Needs?
We do our best to offer the best plant varieties and the most accurate advice for growing them. As we expand our catalog, we like to begin with species we think are the most reliable, with the biggest payoff in ornamental or nutritional value.
Are you looking for a particular plant to grow in your garden this season? If we don't have it, we might be researching the most reputable seed producers for that variety...or, we might just be waiting for someone like you to contact us and make a suggestion! That is, unless you're looking for genetically-modified seeds harvested from chemically-dependent genetic stock, collected by five-year-olds earning slave wages. Can't help you there! As a small family business, we value our customers and, like you, we're committed to supporting sustainable industries.
What's more, when you're planting our seeds, you're growing more than a healthy garden. You're helping us support kids in need around the world through our favorite outreach organizations.
Hansel and Gretel would be proud.