Ornamental · Commelinaceae
Spiderwort
Tradescantia virginiana
Happy in sun or shade, spiderwort rolls out fresh three-petaled flowers every single morning.
Full sun
USDA 4–9
2–3 ft · 0.5–0.9 m
Overview
So what is spiderwort? It's a tough little clump-forming perennial from eastern North America, and it's grown for the steady stream of three-petaled flowers it sends up through late spring and summer. Each one only lasts a morning and fades by afternoon, but here's the thing: the plant just keeps making more, day after day. Its grassy, arching leaves look at home just about anywhere, from a sunny border to a shady woodland edge.
What makes it so easy to please? Mostly its easygoing taste in light and soil. Sure, it flowers best in full sun, but it's just as content in partial or even deep shade, and it doesn't mind clay, sand, chalk, or wet ground that would sink fussier plants. It's hardy down to zone 4, so it comes back on its own year after year and barely asks for a thing once it's settled.
There's one little quirk to know about, and that's the midsummer slump. After the big first flush of flowers, the clump tends to sprawl and brown out, especially when it's hot. Not to worry, though: give it a hard cutback and fresh growth follows, often with a whole second round of blooms in late summer.
Care
The short version: pop it into moist, fertile soil somewhere between sun and shade, water it when things get dry, and cut the whole clump back hard after that first flush so it bounces back looking fresh.
Light
Spiderwort flowers best in full sun, but it won't complain about partial or even deep shade. And if your summers run hot? A little afternoon shade helps it stay upright and takes the edge off that midsummer slump.
Water
Try to keep the soil consistently moist to occasionally wet, because this is a plant that likes it damp. Water it through any dry spell, especially right after a cutback, and you'll nudge up plenty of fresh growth from the base.
Soil
The good news is it'll grow in pretty much anything, clay, loam, sand, or chalk, even wet ground or soil near a black walnut. It's happiest in fertile, moist but well-drained soil, and it's fine with a wide pH from 6.0 to 8.0.
Temperature
This one's hardy and easygoing. It shrugs off cold down to about -29°F (-34°C) and takes summer heat up to 95°F (35°C), though that high heat is exactly what gets the foliage sprawling and browning.
Humidity
Regular outdoor humidity is all it wants, so there's no number to worry about. What really helps is good airflow, since crowded, damp clumps are where rust and leaf spot tend to move in.
Feeding
Here's a plant that barely needs feeding. Just give it a light feed of balanced fertilizer or compost when growth kicks off in spring, and leave it at that, because overdoing it only makes the stems floppy.
Pruning
Snip off the faded flowers and you'll often coax out a second late-summer flush. Once the foliage sprawls or browns after the first flush, don't be shy about shearing the stems back hard, then cut everything down to the ground when the season's done.
Repotting
It's a garden plant, so you won't be repotting it, but it does like a divide now and then. Lift and split the clump every 3 to 4 years to keep it going strong, especially if the middle starts thinning out or the flowers taper off.
Size & spacing
Figure on a clump reaching 1.5 to 3 feet (46 to 91 cm) tall and spreading 12 to 18 inches (30 to 46 cm) wide. Give each one that much elbow room so air moves through and the leaves stay healthy.
When to plant
Spiderwort likes to follow the seasons, so timing's pretty simple. Set plants out in spring once the frost's behind you, or tuck container-grown ones in during autumn, and you'll get flowers from late spring through early July, often with a second show into late summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring after frost; container plants can also be set out in autumn
- Harvest: Late spring through early July (May-July), often reblooming into late summer; cultivars can flower June-September
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Here's the good news: spiderwort hardly ever gives you real grief, and most of what shows up is just cosmetic. Think a midsummer flop, a bit of slug nibbling, and maybe the odd rust spot. Just match what you're seeing below and jump in before it spreads.
Leaves flop and brown out come midsummer
Don't panic: this is just the plant's natural slowdown after flowering, and summer heat and dry soil only speed it up. Once the main show of flowers wraps up, the clump loosens and the leaves start looking tired. Shear the stems back hard, keep it watered through any dry patch, and fresh growth pushes up from the base to see it through to fall.
Fix:
- Shear or cut the stems back hard after flowering
- Water during dry spells to encourage fresh basal regrowth
- Allow the plant to reflush in late summer and fall
Something's chewing ragged holes in the new shoots
More often than not it's slugs and snails going after those soft spring shoots, and you'll usually spot slime trails right next to the chewed edges. They're worst in damp, shady corners. Head out in the evening and pick them off by hand, clear away the wet debris they hide in, and set out traps or barriers if they just won't quit.
Fix:
- Hand-pick slugs and snails, especially in the evening
- Reduce moist hiding spots and debris near the crown
- Use slug traps or barriers if damage is heavy
Rusty spots and pustules turning up on the leaves
When a clump gets damp and crowded, rust and fungal leaf spot can settle in, showing up as orange-brown pustules or scattered blotches. The fix is simple: pull off the marked leaves and bin them, then thin and cut the clump back so air can move through. Keep water off the leaves and you'll head off most of it before it even starts.
Fix:
- Remove and dispose of affected foliage
- Cut back and thin congested clumps to improve airflow
Toxicity
Honestly, spiderwort is more of a skin irritant than anything you'd call poisonous. The sap can leave an itchy rash on bare skin, so it's worth grabbing gloves before you cut it back or divide it, and a pet that chews a leaf might get a slightly upset stomach. Keep the nibblers away from it, sure, but a stray bite really isn't a big deal.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
If a cat chews the leaves or stems, it might get a mild tummy ache, and the sap can leave its mouth or skin a bit irritated. Keep an eye out for drooling or some pawing at the face.
Dogs Mild
A dog that nibbles the foliage could drool a bit or have a short run of mild GI upset. And where the sap touches, it can redden the skin around the muzzle.
Horses Caution
The ASPCA flags the whole genus for horses, and skin irritation's the main worry there. So it's best not to let grazing horses make a habit of the leaves.
Rabbits Caution
That irritant sap can leave a rabbit with a sore mouth and a bit of an upset stomach, so it's really not a green you'd want to offer.
Livestock Caution
Goats, sheep, and cattle usually give it a pass, but a mouthful of those sappy stems can irritate the mouth and gut. Still, a stray nibble here and there is nothing to stress about.
Birds Caution
That same irritant sap makes spiderwort a poor pick around pet birds, since they can react to even a little bit.
People Caution
The sap's a known skin allergen and can bring up an itchy rash, so it's worth pulling on gloves before you cut the plant back or divide it. Nobody's eating any part of it, so really the risk is to your skin, not your stomach.
Sap can cause contact dermatitis and is a skin allergen; wear gloves and protective equipment when cutting back or dividing.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Garden spiderwort comes in a handful of named types, and they mostly differ by flower color and how bright the leaves are. Here are the ones worth knowing about.
'Sweet Kate' (syn. 'Blue and Gold')
Its deep blue-purple flowers really pop against bright golden-chartreuse leaves, all on a compact plant that's 12 to 24 inches (30 to 60 cm) tall.
'Concord Grape'
Think rich grape-purple flowers hovering over cool blue-green leaves.
'Zwanenburg Blue'
This is a vigorous Andersoniana Group pick, and it carries big, deep blue-purple flowers.
'Satin Doll'
It's got soft pink flowers on a neat, compact little plant.
'Billberry Ice' / white-flowered forms
Its clear white, three-petaled flowers are just the thing for brightening a shady spot.
How to propagate
Want more spiderwort? It's about as easy as perennials get. You can split up an established clump, or just let the plant scatter a bit of its own seed around the garden.
DivisionEasy
Spring, or in autumn after flowering · Reaches full size in 1-2 years
Division's the surest way to get more plants, and the best time is spring or autumn once flowering's finished. Just lift a crowded clump and pull or cut it into chunks, making sure each piece keeps its own roots and shoots. Replant them and they'll fill out to full size in 1 to 2 years, and splitting things up every few years keeps the parent plant nice and vigorous.
SeedModerate
Sow seed in spring; plants also self-sow readily in the garden · 1-2 years to mature, flowering-size clumps
Spiderwort sows itself all over the place, so seed-grown plants pretty much raise themselves once you sow in spring, hitting flowering size in 1 to 2 years. The catch? Named cultivars won't come true from seed, so those are better off divided. And if the self-seeding's getting a little enthusiastic, just snip back the spent flower stems to keep it in line.
Myths
Garden spiderwort is basically the same thing as those trailing inch plant houseplants.
Not quite. Tradescantia virginiana and the x andersoniana garden hybrids are cold-hardy, clump-forming border perennials, tough all the way down to zone 4. Those tender tropical trailers you see sold as houseplants, like T. zebrina and T. fluminensis? Totally different plants. The hardy garden spiderworts stay put as neat clumps, but tropical T. fluminensis turns invasive across the warm southern states, so it's best skipped.
Spiderwort has to have full sun to do well.
It does flower most freely in full sun, that part's true, but it takes partial and even deep shade without missing a beat. And in hot-summer regions, a bit of afternoon shade actually helps, easing off that midsummer flop.