Ornamental · Commelinaceae
Spiderwort
Tradescantia virginiana
Relaxed in sun or shade, spiderwort opens a fresh set of three-petaled blooms each morning.
Full sun
USDA 4–9
2–3 ft · 0.5–0.9 m
Overview
Spiderwort brings an unstudied, cottage-garden ease to a border, a clump-forming perennial from eastern North America that carries three-petaled flowers in a long, casual run from late spring into summer. Each bloom is fleeting, open in the morning and gone by afternoon, yet the plant restocks itself daily, so the display never really pauses. Its loose, grassy foliage reads as soft and informal, at home along a sunny path or drifting into the shade at a woodland edge.
Half its charm is how agreeably it fits almost any setting. It gives the most flowers in full sun but looks just as composed in partial or deep shade, and it takes to clay, sand, chalk, or damp ground where choosier plants would sulk. Hardy to zone 4, it settles into a planting for the long term and asks for very little attention, which makes it a quietly dependable partner in a relaxed scheme.
The one thing to design around is its midsummer lull. When the first flush is spent the clump tends to relax and brown, more so in heat, and a border can look tired for a spell. A firm cutback resets the picture, bringing fresh growth and often a second wave of bloom to carry the planting into late summer.
Care
The short version: site spiderwort in moist, fertile soil anywhere from sun to shade, water it through dry spells, and cut the whole clump back hard after the first flush to keep the planting looking crisp.
Light
Spiderwort blooms most freely in full sun, yet it stays poised in partial and even deep shade, which makes it easy to place. Where summers turn hot, a little afternoon shade keeps it upright and eases the midsummer lull that can unsettle a border.
Water
Keep the soil consistently moist to occasionally wet, since this is a plant that favors damp ground. See it through any dry spell, and water in particular after a cutback, to encourage the fresh growth that restores the display.
Soil
It settles into almost any soil, clay, loam, sand, or chalk, and even wet ground or a spot near black walnut. A fertile, moist but well-drained bed suits it best, and it accepts a broad pH from 6.0 to 8.0.
Temperature
This is a hardy, undemanding plant for the open garden. It takes winter cold to around -29°F (-34°C) and summer heat up to 95°F (35°C), though that high heat is what prompts the foliage to relax and brown.
Humidity
Ordinary outdoor air is all it needs, so humidity is never a concern. What matters more for a clean look is good airflow, since crowded, damp clumps are where rust and leaf spot take hold.
Feeding
This is a plant of modest appetite. A light feed of balanced fertilizer or compost as growth begins in spring keeps it handsome, and heavier feeding only invites the floppy stems that spoil the line of a border.
Pruning
Deadhead the spent flowers to draw out a second late-summer flush and keep the planting looking fresh. When the foliage relaxes or browns after the first flush, shear the stems back hard, then cut everything to the ground as the season closes.
Repotting
In the ground it is divided rather than repotted, and a regular split keeps a clump looking its best. Lift and divide it every 3 to 4 years, especially once the center thins or flowering tails off, to hold the shape and vigor of the planting.
Size & spacing
A mature clump stands 1.5 to 3 feet (46 to 91 cm) tall and spreads 12 to 18 inches (30 to 46 cm) across. Allow each plant that much space so it reads cleanly in a bed and air moves freely through the foliage.
When to plant
Spiderwort moves with the garden's calendar. Plant it out in spring once frost has passed, or slot container-grown clumps in through autumn, and the flowers arrive from late spring through early July, often returning for an encore 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
Spiderwort asks little and seldom disappoints, and the few issues it raises are cosmetic rather than serious. A midsummer lull, some slug damage, and the occasional rust spot make up nearly the whole list. Match the symptom below and tidy it up before it spreads.
The clump loosens and browns through the heat of midsummer
This is the plant's natural lull after blooming, brought on faster by summer heat and dry soil. Once the main flush passes, the clump opens and the foliage fades, leaving a gap in the border. Shear the stems back hard, water through any dry spell, and fresh growth rises from the base to carry the picture into 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
Ragged edges appear on the soft new growth
The soft spring shoots are a favorite of slugs and snails, which leave slime trails beside the chewed leaf edges. Damage runs worst in the damp, shaded corners of a planting. Pick them off by hand in the evening, clear the wet debris they shelter in, and set out traps or barriers if they keep returning.
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
Orange-brown spots settle across the leaves
Damp, crowded clumps invite rust and fungal leaf spot, seen as orange-brown pustules or scattered blotches across the foliage. Remove the marked leaves and bin them, then thin and cut back the clump so air can circulate. Keeping water off the leaves prevents most of it from taking hold.
Fix:
- Remove and dispose of affected foliage
- Cut back and thin congested clumps to improve airflow
Toxicity
Spiderwort is better thought of as a skin irritant than a poison, an easy plant to live alongside with a little care. The sap can bring up an itchy rash, so gloves belong on the job whenever you cut it back or divide it, and a pet that samples a leaf may get a mildly upset stomach. Keep curious animals from grazing it, and take a stray nibble in stride.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
A cat that chews the leaves or stems may develop a mild stomach upset, and the sap can leave its mouth or skin irritated. Look for drooling or a little pawing at the face.
Dogs Mild
A dog that nibbles the foliage might drool or pass through a brief bout of mild GI upset. Where the sap makes contact, it can redden the skin around the muzzle.
Horses Caution
The ASPCA lists the genus for horses, with skin irritation the chief concern. Keep grazing horses from returning to the foliage as a habit.
Rabbits Caution
The irritant sap can leave a rabbit with a sore mouth and some stomach upset, so it makes a poor choice of green to offer.
Livestock Caution
Goats, sheep, and cattle rarely graze it, but a mouthful of the sappy stems can irritate the mouth and gut. A stray nibble, though, calls for no real concern.
Birds Caution
The same irritant sap makes spiderwort an unwise plant to keep near pet birds, which can react to even small amounts.
People Caution
The sap is a recognized skin allergen that can raise an itchy rash, so wear gloves before you cut the plant back or divide it. No part of it is eaten, so the risk stays with your skin rather than 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 offers a tidy edit of named selections, chosen mainly for flower color and the tone of the foliage. These are the ones worth building a planting around.
'Sweet Kate' (syn. 'Blue and Gold')
Deep blue-purple flowers play against bright golden-chartreuse foliage on a compact plant of 12 to 24 inches (30 to 60 cm), a natural focal point for a bed.
'Concord Grape'
Rich grape-purple flowers rise over cool blue-green foliage for a quietly elegant pairing.
'Zwanenburg Blue'
A vigorous Andersoniana Group selection that carries large, deep blue-purple flowers with real presence.
'Satin Doll'
Soft pink flowers on a tidy, compact habit bring a gentler note to a planting.
'Billberry Ice' / white-flowered forms
Clear white, three-petaled flowers lighten a shady corner of the garden.
How to propagate
Few perennials are as generous to increase as spiderwort. Lift and split an established clump, or let it self-sow a little around the beds and fold the seedlings into the scheme.
DivisionEasy
Spring, or in autumn after flowering · Reaches full size in 1-2 years
Division is the surest route to more plants, best done in spring or in autumn once flowering has finished. Lift a congested clump and separate it into pieces, each keeping its own roots and shoots to grow away. Replanted, those divisions reach full size within 1 to 2 years, and dividing every few years keeps the parent clump full and vigorous for the border.
SeedModerate
Sow seed in spring; plants also self-sow readily in the garden · 1-2 years to mature, flowering-size clumps
Spiderwort scatters its own seed with ease, so plants raised from a spring sowing largely see to themselves and reach flowering size in 1 to 2 years. Named cultivars are the exception, since they do not come true from seed and are better divided to hold their character. Trimming back the spent flower stems keeps the self-seeding from spreading further than a tidy scheme allows.
Myths
The border spiderwort and the trailing inch plant sold indoors are one plant.
They are relatives, not the same plant. Tradescantia virginiana and the x andersoniana garden hybrids are cold-hardy, clump-forming border perennials, dependable to zone 4. The tender tropical trailers grown as houseplants, such as T. zebrina and T. fluminensis, belong to a warmer world. The hardy garden spiderworts keep to well-behaved clumps, while tropical T. fluminensis turns invasive across the warm southern states and is best avoided.
Spiderwort only earns its place in full sun.
Full sun does bring the most flowers, but the plant carries partial and even deep shade with ease. In hot-summer regions a little afternoon shade actually flatters it, softening the midsummer lull and keeping a planting looking settled.