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 is grown for its leaves, not its flowers. The felted, silver-white foliage is what draws gardeners in, working as a cool, calm backdrop that makes the reds, purples, and pinks of its bedmates look sharper. It belongs to the daisy family and started out around the Mediterranean coast, which explains its taste for sun and its dislike of soggy ground.
It earns its keep as a warm season annual in most gardens, though it is really a tender perennial that can live for years where winters stay mild. Expect a low, mounding plant somewhere between 8 and 24 inches (20 to 61 cm) tall, depending on the variety. The fine silver leaves come lacy and cut on some selections and broad and rounded on others.
This is an easy plant that shrugs off heat and drought once it settles in. The one thing it won't forgive is wet feet. Give it sun and soil that drains, pinch it now and then to keep it full, and it holds its color from spring until frost.
Care
The short version: full sun and light, fast-draining soil, watered deeply but only when the top half has dried out. Pinch the young plants to keep them bushy, and go easy on both water and nitrogen.
Light
Give dusty miller full sun, ideally 6 or more hours a day, and the leaves stay tight, compact, and brightly silver. It puts up with light shade, but in real shade the plant stretches, flops, and loses much of its color.
Water
Water deeply, then wait until the top half of the soil has dried before the next drink, which usually lands somewhere around every 7 to 10 days. It handles heat and drought well once established. What it can't stand is sitting wet, so never let the roots stay soggy.
Soil
Plant it in light, well-drained soil of only moderate fertility. It even does fine in poor ground, but drainage is the part that matters, since waterlogged soil rots the roots and stems fast.
Temperature
Dusty miller takes a wide range, from about 10°F to 95°F (-12°C to 35°C), which is why it works as a tough bedding plant. It handles a light frost in mild zones but won't survive a hard freeze.
Humidity
Ordinary outdoor air suits it, so there's no number to watch. Airflow counts for more than humidity, 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 expense of the compact silver look you're after.
Pruning
Pinch the young plants to push them into a bushy, compact shape. Many gardeners also snip off the flower buds so the plant pours 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
Dusty miller is grown as a frost-tender annual in most gardens. Start the seed indoors in late winter, set the plants out once the cold has passed, and enjoy the silver foliage straight through to fall. Any summer flowers are small and dull, and most gardeners simply snip 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
Dusty miller stays trouble-free as long as it gets sun and dry roots. When something does go wrong, it usually traces back to too much shade or too much water. Match what you see below and fix the cause, not just the symptom.
Wilting plants with blackened, mushy stem bases
Soggy soil brings on root and stem rot, and a dusty miller hates wet feet more than almost anything. The stem turns soft and dark at the base while the roots go brown and mushy. Improve the drainage, water less often, and replant the survivors in light, fast-draining soil.
Fix:
- Improve drainage and reduce watering frequency
- Remove severely affected plants
- Replant in light, well-drained soil
Orange to brown raised spots on the leaves
Those raised pustules are rust, a fungus that takes hold when plants sit damp and crowded. Pull off the marked leaves and bin them, give each plant more room, and keep water off the foliage by watering at the soil line.
Fix:
- Remove and destroy affected foliage
- Improve air circulation by spacing plants
- Avoid overhead watering
Stretched, floppy stems with gaps between the leaves
This is legginess, and it almost always means the plant isn't getting enough sun. Too much nitrogen pushes the same soft, stretched growth. Move it into full sun, pinch the stem tips to force it to branch, and ease off 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 to grow where animals graze. Every part holds pyrrolizidine alkaloids, the same liver-damaging compounds found in ragwort, and they build up with every dose rather than passing through. A curious pet that takes one bite usually gets off with a mild stomach upset, but horses and livestock that eat it over time face real harm. Nothing on this plant is meant to be eaten.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
A nibble usually causes drooling or a bout of vomiting and little else. The real concern is the slow liver damage that builds up if a cat keeps coming back to the plant, so move it out of reach.
Dogs Mild
Most dogs that chew a leaf get away with a mild upset stomach. Watch for repeat visits, though, since the alkaloids settle in the liver and add up over time.
Horses Severe
Horses are the ones most at risk here. The toxin gathers in the liver with every mouthful and brings on weight loss, weakness, jaundice, sunburned skin, and odd behavior like aimless walking or pressing the head against a wall. Keep it well clear of paddocks and hay.
Rabbits Caution
The same liver-damaging alkaloids are present, so don't offer dusty miller as forage. A curious rabbit that tastes a little is unlikely to suffer, but it isn't a green you want in the hutch.
Livestock Severe
Cattle, goats, and sheep face the worst danger because they graze the plant or eat it dried in hay, where the bitter taste fades. Repeated feeding builds toward liver failure, weight loss, and photosensitive skin, so keep it out of pastures and stored feed.
Birds Caution
Treat dusty miller as off-limits for pet birds and poultry. The pyrrolizidine alkaloids that harm mammals are no safer for a bird's liver, so don't let it become a snack.
People Caution
No part of this plant is grown to eat. Eating it in any quantity can stress the liver thanks to the same alkaloids, so keep it out of the kitchen and away from small children who 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 sold is one of a few named selections, set apart mainly by leaf shape and how tall they grow. These are the ones you're likely to find.
Silver Dust
The most widely grown choice, a compact 10 to 12 inch plant prized for its lacy, deeply cut silver-white leaves.
Cirrus
A shorter 8 inch mound that trades the usual lacy look for broad, rounded, undivided silver leaves.
New Look
A compact 10 inch selection with large, broad, felted leaves that read as solid silver from a distance.
Candicans
The tall one of the bunch 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 root 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
Start seed indoors a good way ahead, roughly 10 to 15 weeks before your last frost. The seed needs light to wake up, so press it onto the surface and leave it uncovered, holding the tray at 68°F to 77°F (20°C to 25°C). Sprouts show in about two weeks, and the young plants go outside once the frost danger has passed.
Stem cuttingsModerate
Take cuttings in fall to overwinter under glass in cold climates · Several weeks to root
Cuttings are the trick for saving a plant where winters turn cold. Take them in fall and root them under glass, which runs several weeks, then carry the young plants through to spring rather than letting frost claim the parent.
Myths
Dusty miller only bothers livestock and is completely safe around cats and dogs.
Every ragwort and Senecio relative carries pyrrolizidine alkaloids, so the plant is listed as toxic to cats, dogs, and horses alike. The risk to a pet is smaller and usually stops at a mild stomach upset, but it is not a non-toxic plant, and repeated nibbling can still wear on the liver.
Animals always leave dusty miller alone because it tastes bitter.
The fresh plant is bitter enough that most animals pass it by when better food is around. That safety net falls apart once forage runs short or the plant ends up dried in hay, where the bitter edge fades and horses no longer reliably refuse it.