Ornamental · Asteraceae
Dusty Miller
Jacobaea maritima
Plant it for the silver foliage that sets every other color off, give it sun and sharp drainage, and it asks for almost nothing.
Full sun
Every 7–10 days
USDA 7–10
8–24 in · 20–61 cm
Overview
Dusty miller earns its place in a planting scheme for the leaves rather than the bloom. That silver-white foliage is the draw, settling into a bed as a cool, restful foil that makes the reds, purples, and pinks of its neighbors look crisper. It sits in the daisy family and traces back to the Mediterranean coast, which accounts for its love of sun and its dislike of soggy ground.
It pulls its weight as a warm season annual in most gardens, though it is truly a tender perennial that carries on for years where winters stay gentle. Picture a low, mounding shape somewhere between 8 and 24 inches (20 to 61 cm) tall, depending on the variety, lacy and cut on some selections and broad and rounded on others.
This is an easy plant that brushes off heat and drought once it has settled in. The one thing it will not abide is wet feet. Place it in sun and free-draining soil, pinch it from time to time to keep the shape full, and it holds its silver from spring right through to frost.
Care
The short version: full sun and light, fast-draining soil, watered deeply but only once the top half has dried out. Pinch the young plants to keep them full, and go easy on both water and nitrogen.
Light
Settle dusty miller into full sun, ideally 6 or more hours a day, and it keeps its tight, compact, brightly silver look. It tolerates light shade, but in genuine shade the plant stretches, flops, and loses much of its color.
Water
Soak it deeply, then hold off until the top half of the soil has dried before the next drink, which usually falls somewhere around every 7 to 10 days. Once established it shrugs off heat and drought. What it cannot abide is sitting wet, so never let the roots stay soggy.
Soil
Set it in light, well-drained soil of only moderate fertility. It even copes with poor ground, but drainage is the part that counts, since waterlogged soil rots the roots and stems fast.
Temperature
Dusty miller works across a wide range, from about 10°F to 95°F (-12°C to 35°C), which is why it makes such a dependable bedding plant. It takes a light frost in mild zones but will not survive a hard freeze.
Humidity
Ordinary outdoor air suits it, so there is no number to track. Airflow matters more than humidity here, because crowded, damp foliage is what invites rust.
Feeding
A monthly balanced feed through the growing season is plenty. Keep the nitrogen light, since a heavy hand pushes soft, leggy growth at the cost of the compact silver shape you are after.
Pruning
Pinch the young plants to coax them into a bushy, compact shape. Many gardeners also snip off the flower buds so the plant puts its energy into foliage. In mild zones, cut frost-damaged growth back to the crown and fresh leaves return in late spring.
Size & spacing
Plants mound up 8 to 24 inches (20 to 61 cm) tall and spread about as wide. Set them roughly 12 inches (30 cm) apart so air moves freely between them and rust stays away.
When to plant
In most gardens dusty miller is treated as a frost-tender annual. Start the seed indoors in late winter, set the plants out once the cold has lifted, and let the silver foliage carry the scheme straight through to fall. The summer flowers stay small and dull, and most gardeners simply pinch them off.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 10 to 15 weeks before the last spring frost; surface sow and do not cover seed as light aids germination at 68 to 77°F
- Plant: After all danger of frost has passed, spacing about 12 inches apart
- Harvest: Grown for silver foliage; insignificant cream to yellow daisy-like flowers may appear in summer and are usually removed
Hardiness
USDA hardiness zones: 7–10
Temperature: down to -18°C
Troubleshooting
Given sun and dry roots, dusty miller stays untroubled. When something does slip, it nearly always comes back to too much shade or too much water. Match what you are seeing to the cases below and treat the cause, not just the symptom.
Drooping plants going dark and soft at the base
Standing water sets off root and stem rot, and few plants resent wet feet as much as a dusty miller. The base of the stem turns soft and dark while the roots fade to brown and mush. Open up the drainage, water more sparingly, and reset the survivors in light, quick-draining soil.
Fix:
- Improve drainage and reduce watering frequency
- Remove severely affected plants
- Replant in light, well-drained soil
Orange to brown bumps breaking out across the leaves
Those raised bumps are rust, a fungus that settles in where plants stand damp and packed together. Strip the marked leaves and bin them, open up the spacing so each plant breathes, and keep water off the foliage by directing it to the soil.
Fix:
- Remove and destroy affected foliage
- Improve air circulation by spacing plants
- Avoid overhead watering
Loose, reaching stems that leave gaps in the planting
What you are seeing is legginess, and a shady spot is nearly always behind it. A heavy nitrogen feed pushes the same soft, reaching habit. Shift the plant into full sun, pinch the tips so it branches and fills back in, and lighten the feeding.
Fix:
- Move or plant in full sun (6+ hours)
- Pinch back stem tips to force branching
- Reduce nitrogen feeding
Toxicity
This is not a plant for a garden where animals graze. Every part carries pyrrolizidine alkaloids, the same liver-damaging compounds found in ragwort, and they build up with each dose rather than clearing the body. A curious pet that takes a single bite usually gets off with a mild stomach upset, while horses and livestock that eat it over time face real harm. Nothing on this plant is meant for the table.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
One taste tends to bring on some drooling or a spell of vomiting and not much beyond that. The lasting worry is the quiet liver damage that builds when a cat keeps returning to the same plant, so set it somewhere out of reach.
Dogs Mild
A dog that gnaws a leaf usually walks away with nothing worse than a queasy stomach. Keep an eye out for repeat trips, though, because the alkaloids lodge in the liver and accumulate over time.
Horses Severe
Horses sit at the top of the risk list here. The toxin collects in the liver with each mouthful and leads to weight loss, weakness, jaundice, sunburned skin, and strange behavior such as aimless wandering or pressing the head into a wall. Keep it well away from paddocks and hay.
Rabbits Caution
Those same liver-damaging alkaloids are present, so dusty miller has no place as forage. A curious rabbit that samples a little will most likely be fine, but it is not a green that belongs in the hutch.
Livestock Severe
Cattle, goats, and sheep are in the most danger because they graze the plant or take it in dried hay, where the bitter note disappears. Feeding it again and again pushes them toward liver failure, weight loss, and photosensitive skin, so keep it clear of pastures and stored feed.
Birds Caution
Count dusty miller as strictly off-limits for pet birds and poultry. The pyrrolizidine alkaloids that harm mammals are just as unkind to a bird's liver, so never let it turn into a snack.
People Caution
Nothing on this plant is grown for the table. Swallowing any amount can tax the liver because of those same alkaloids, so keep it out of the kitchen and away from small children who like to taste-test the garden.
Keep grazing animals away; pyrrolizidine alkaloids accumulate in the liver and cause cumulative damage with repeated ingestion. Greatest danger is to horses and livestock eating green plant material or contaminated hay over time.
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
Most dusty miller for sale comes down to a handful of named selections, set apart mainly by leaf shape and how tall they grow. These are the ones you are most likely to come across.
Silver Dust
The default pick in most gardens, a tidy 10 to 12 inch plant valued for its lacy, deeply cut silver-white leaves.
Cirrus
A lower 8 inch mound that swaps the familiar lacy outline for broad, rounded, undivided silver leaves.
New Look
A neat 10 inch selection whose large, broad, felted leaves read as solid silver across a border.
Candicans
The tallest of the group at 16 to 24 inches, carrying big lobed leaves on a fuller frame.
How to propagate
You can raise dusty miller from seed each spring or take cuttings to carry a favorite plant through a cold winter.
SeedModerate
Start indoors 10 to 15 weeks before the last spring frost; surface sow without covering at 68 to 77°F · Germinates in about 2 weeks; transplant outdoors after frost danger passes
Give seed a long head start indoors, around 10 to 15 weeks before your last frost. Light is what wakes it up, so press the seed onto the surface and leave it uncovered, holding the tray at 68°F to 77°F (20°C to 25°C). Seedlings appear in roughly two weeks, and the young plants head outdoors once frost danger has passed.
Stem cuttingsModerate
Take cuttings in fall to overwinter under glass in cold climates · Several weeks to root
Cuttings are the way to keep a favorite plant going where winters bite. Take them in fall and root them under glass, a process of several weeks, then carry the young plants into spring instead of leaving the parent to the frost.
Myths
Dusty miller is a danger only to livestock and stays perfectly safe around cats and dogs.
Every ragwort and Senecio relative holds pyrrolizidine alkaloids, which is why the plant is listed as toxic to cats, dogs, and horses together. The hazard to a pet is smaller and usually ends at a mild stomach upset, yet it is not a non-toxic plant, and repeated nibbling can still tax the liver.
Its bitter taste means animals will always steer clear of dusty miller.
The fresh plant is bitter enough that most animals walk past it while better grazing is on hand. That defense collapses once forage gets scarce or the plant turns up dried in hay, where the bitter edge fades and horses can no longer be trusted to refuse it.