Ornamental · Plantaginaceae
Beardtongue
Penstemon digitalis
Give it full sun and sharp drainage and this easygoing native will reward you with white spikes the bees adore.
Full sun
Every 7–14 days
USDA 3–8
2–4 ft · 0.6–1.2 m
Overview
Beardtongue is a clump-forming native perennial from the figwort family, and it is a wonderfully forgiving choice for a sunny border. From late spring into early summer it sends up tall spikes of white, two-lipped tubular flowers that buzz with bees and the occasional hummingbird. The common name foxglove beardtongue only nods to the flower shape, so there is no need to link it with true foxglove.
The lovely thing is how little this plant asks of you. It shrugs off cold down to -29°F (-34°C), carries on through dry stretches once its roots are settled, and grows fast enough to fill a bare patch within a single season. Offer it sun and ground that drains, and it will happily look after itself.
The one gentle habit to keep an eye on is its urge to spread. Beardtongue self-seeds and the clump widens a little each year, so it may stray past the spot you first gave it. A bit of deadheading and a division every few years is all it takes to guide it back, and none of it is hard.
Care
The short version: full sun and sharp drainage are the heart of it. Water moderately while the plant is finding its feet, then let it ride out dry spells, feed it almost nothing, and lift and divide the clump every 2 to 3 years to keep the flowers coming.
Light
Your beardtongue will flower at its happiest in full sun, where the spikes stand tall and bloom generously. It will still take partial sun or light shade if that is what you have, though the plant grows a little looser and hands you fewer flowers in the bargain.
Water
While the plant is settling in, water moderately and let the top half of the soil dry between drinks, which usually works out to every 7 to 14 days. Once it is established it copes with drought beautifully, and the real risk runs the other way, since wet or poorly drained soil rots the roots, so when in doubt lean dry.
Soil
This is not a fussy plant, and it grows contentedly in loam, clay, or sand as long as the drainage is good. Aim for a pH between 5.5 and 7.0, and take comfort that sharp drainage matters much more here than rich, pampered soil.
Temperature
This is a tough, cold-hardy native that rides out winters down to -29°F (-34°C) and summer heat up to around 86°F (30°C). That generous range covers a wide stretch of the country, so most gardeners can grow it with no special fuss.
Humidity
Ordinary outdoor humidity suits it just fine, so there is no number you need to chase. Fresh air moves the needle more than moisture ever will, because still, crowded conditions are what give leaf spot its opening.
Feeding
As a native that flourishes on lean ground, beardtongue barely needs feeding, which is one less thing to remember. A light spring helping of balanced fertilizer or a little compost is plenty, and rich feeding only leaves the plant floppy.
Pruning
Deadhead the faded flower spikes through the season to keep things neat and to gently curb self-sowing. Cut the foliage back in late fall or early spring to make room for fresh new growth, and it will thank you for it.
Repotting
Beardtongue lives in the ground rather than a pot, but it does welcome a regular refresh. Divide the clump every 2 to 3 years to keep it vigorous, and let a fading bloom or a crowded, dying center be your friendly cue that it is time.
Size & spacing
In flower your plants reach 2 to 4 feet (60 to 120 cm) tall and settle into a clump 18 to 24 inches (45 to 60 cm) across. Give them room for that spread so air flows freely and leaf spot stays away.
When to plant
Beardtongue keeps a gentle cool-season rhythm, and once you know it the timing feels easy. Its seed wants a cold, moist chill before it will wake up, so sow outdoors in fall or start it indoors in late winter after stratifying, set your plants out in spring once the frost has gone, and enjoy the white spikes from May to July.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter after 1-3 months cold-moist stratification
- Plant: Spring after last frost
- Harvest: May to July
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Beardtongue has very few real troubles, and the ones it does have usually come back to wet soil or a clump that has simply grown too big for its space. Find what matches your plant below and step in early, while a small fix still makes a big difference.
A wilting plant with a darkened base and soft roots
Take heart, because this is usually just root or crown rot from ground that has stayed too wet, most often over winter. Your beardtongue copes with dry spells much more happily than with sodden soil, so you fix this by helping the water drain away, not by watering more. Shift the plant to a raised, free-draining spot, gently clear away anything that has already gone soft, and it can bounce back.
Fix:
- Improve drainage by amending soil or relocating to a raised, well-drained site
- Reduce watering and avoid wet winter soils
- Remove and discard severely rotted plants
The plant wandering past its spot and leaning on neighbors
This is nothing to fret over, because beardtongue simply self-seeds and slowly widens its clump, and in a happy garden it can drift a bit further than you planned. Snip the faded spikes before they set seed and you gently slow the self-sowing, then lift out any small volunteers you would rather not keep. Digging up and dividing the clump every few years is an easy way to keep it right where you love it.
Fix:
- Remove unwanted seedlings
- Deadhead before seed set to limit self-sowing
- Divide and thin the clump
Little spots and blotches showing up on the leaves
Try not to worry, since these marks are only fungal leaf spot, which turns up now and then and is mostly a looks problem. Simply pinch off the leaves that are affected and your plant keeps growing along just fine. What really helps is fresh air, so give it a little breathing room and try to keep water off the leaves.
Fix:
- Remove and dispose of affected leaves
- Improve air circulation and avoid overhead watering
Toxicity
Here is some reassuring news: beardtongue is safe. For all the foxglove in its common name, it holds none of true foxglove's poison and sits on no toxic plant list, so you can enjoy it freely around cats, dogs, livestock, and curious children.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
You can relax with cats around beardtongue, since it holds no toxic compounds at all. If a curious cat takes a nibble, there is nothing here to poison it.
Dogs None
Dogs are welcome near this plant with nothing to fear. A big mouthful of any greenery might unsettle a tummy, but no real toxin waits in these leaves.
Horses Safe
Your horses come to no harm from beardtongue. None of the cardiac trouble found in true foxglove lives in this plant.
Rabbits Safe
Rabbits are free to graze it without worry. Nothing in the leaves or flowers could poison them.
Livestock Safe
Grazing cattle, goats, and sheep are perfectly fine near this plant. It appears on no list of things that harm livestock.
Birds Safe
Birds are safe among the foliage and seed. The plant even shares nectar with pollinators and puts no bird at risk.
People Safe
People, little ones included, have nothing to fear from beardtongue. Its name tips a hat to foxglove, yet it carries none of that plant's poison.
Generally safe around pets and people; no special handling required.
Varieties
Most gardens grow either the wild species or one much-loved cultivar treasured for its dark foliage. These are the two worth getting to know.
Husker Red
This is the beloved one crowned 1996 Perennial Plant of the Year, prized for maroon-red spring leaves that soften toward green with age while its maroon veining and red stems stay on show.
Foxglove Beardtongue (species)
The plain wild form is a joy in its own right, lifting tall clusters of white, two-lipped tubular flowers from late spring into early summer.
How to propagate
Making more beardtongue is genuinely easy, whether you split a settled clump, sow the ripe seed, or root a few summer cuttings to keep a favorite cultivar true to itself.
DivisionEasy
Spring · One growing season
Dividing is the friendliest way to grow more beardtongue while keeping the parent clump strong, and it is hard to get wrong. In spring, every 2 to 3 years, lift the clump and gently pull it into pieces, and each division settles back in comfortably over one growing season.
SeedModerate
Fall sow outdoors or stratify and sow late winter · Germinates best with cold-moist stratification and light; blooms typically the following year
Seed ripens in fall and comes up most readily after a cold, damp rest and a touch of light, so this one just asks for a little patience. Sow it outdoors in fall and let winter do the chilling for you, or stratify and start it in late winter, and you can look forward to your first blooms the following year.
Stem cuttingsModerate
Summer · Several weeks to root
When you want a named cultivar to stay true, take softwood cuttings in summer, since seed will not hold that special foliage color. Give them several weeks to root, and they will be ready to pot on before you know it.
Myths
Foxglove beardtongue is poisonous like foxglove because of its name.
You can set this fear aside, because the name is truly all that these two plants share. Penstemon digitalis sits in a different genus and holds none of the cardiac glycosides that make real foxglove dangerous. It appears on no toxic plant list and is safe around your pets and family.