Ornamental · Asteraceae
Dusty Miller
Jacobaea maritima
Grow it for the silver foliage that makes every other color pop, hand it sun and sharp drainage, and it asks for next to nothing.
Full sun
Every 7–10 days
USDA 7–10
8–24 in · 20–61 cm
Overview
Dusty miller earns its spot for its leaves, not its blooms. That felted, silver-white foliage pulls gardeners straight in, working as a cool, steady backdrop that sharpens the reds, purples, and pinks planted beside it. It hails from the daisy family and traces back to the Mediterranean coast, which explains its love of sun and its grudge against soggy ground.
It pulls its weight as a warm season annual across most gardens, even though it is really a tender perennial that keeps going for years where winters stay gentle. Count on a low, mounding plant running 8 and 24 inches (20 to 61 cm) tall, depending on the variety. The fine silver leaves turn lacy and cut on some picks and broad and rounded on others.
Here is an easy plant that powers through heat and drought once it digs in. The one thing it will not abide is wet feet. Hand it sun and soil that drains, pinch it here and there to keep it full, and it carries its color from spring straight to frost.
Care
The short version: full sun and light, fast-draining soil, watered deeply but only after the top half dries out. Pinch the young plants to keep them bushy, and stay light on both water and nitrogen.
Light
Hand dusty miller full sun, ideally 6 or more hours a day, and the leaves hold tight, compact, and brightly silver. It puts up with light shade, but drop it into real shade and the plant stretches, flops, and washes out its color.
Water
Soak it deeply, then hold off until the top half of the soil dries before the next drink, which tends to land around every 7 to 10 days. It powers through heat and drought once settled. The one thing it cannot take is sitting wet, so never leave the roots soggy.
Soil
Set it into light, well-drained soil of only moderate fertility. Poor ground suits it just fine, but drainage is the part that counts, since waterlogged soil rots the roots and stems in a hurry.
Temperature
Dusty miller takes a wide swing, running from about 10°F to 95°F (-12°C to 35°C), which makes it a tough bedding pick. It shrugs off a light frost in mild zones but goes down in a hard freeze.
Humidity
Plain outdoor air suits it, so there is no number to track. Airflow matters more than humidity here, because crowded, damp foliage is exactly what calls in rust.
Feeding
A monthly balanced feed across the growing season covers it. Keep the nitrogen light, since a heavy hand drives soft, leggy growth and steals the compact silver look you are chasing.
Pruning
Pinch the young plants to push them into a bushy, compact shape. Plenty of gardeners also clip 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 come back 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 off.
When to plant
Most gardens run dusty miller as a frost-tender annual. Get seed started indoors in late winter, move the plants out once the cold breaks, and ride the silver foliage clear through to fall. The summer flowers come small and dull, so most gardeners just clip 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
Hand dusty miller sun and dry roots and it sails along trouble-free. When something slips, the trail almost always leads back to too much shade or too much water. Match what you spot below and chase the cause, not just the symptom.
Plants wilting with dark, mushy stem bases at the soil
Wet, heavy soil drives root and stem rot, and nothing sets a dusty miller back like soggy ground around its feet. The base of the stem goes soft and black while the roots turn brown and mushy. Sharpen up the drainage, water less often, and move any survivors into light, fast-draining soil.
Fix:
- Improve drainage and reduce watering frequency
- Remove severely affected plants
- Replant in light, well-drained soil
Raised orange to brown spots breaking out across the leaves
Those raised bumps signal rust, a fungus that moves in fast where plants stay damp and packed together. Strip off the spotted leaves and toss them, open up the spacing between plants, and water at the soil line to keep the foliage dry.
Fix:
- Remove and destroy affected foliage
- Improve air circulation by spacing plants
- Avoid overhead watering
Tall, flopping stems with bare gaps showing between the leaves
Stems that stretch and gap out are showing legginess, and the usual culprit is too little sun reaching the plant. A heavy nitrogen feed drives the same soft, lanky growth. Shift it into full sun, pinch the tips to spark fresh branching, and pull back on the fertilizer.
Fix:
- Move or plant in full sun (6+ hours)
- Pinch back stem tips to force branching
- Reduce nitrogen feeding
Toxicity
Skip this plant anywhere animals graze. Every part holds pyrrolizidine alkaloids, the very liver-damaging compounds found in ragwort, and they stack up with each dose instead of passing through. A curious pet that grabs one bite usually walks off with a mild stomach upset, but horses and livestock feeding on it over time meet real harm. Nothing on this plant belongs on a plate.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
One curious nibble tends to bring on a little drooling or a bout of vomiting and not much more. The bigger worry is the slow liver damage that piles up when a cat keeps returning to the plant, so set it somewhere out of paw's reach.
Dogs Mild
A dog that chews a leaf usually walks away with nothing worse than a mild upset stomach. Keep an eye out for repeat visits, since the alkaloids lodge in the liver and stack up with each one.
Horses Severe
Horses carry the highest risk here. The toxin builds in the liver with every mouthful and drives weight loss, weakness, jaundice, sunburned skin, and strange behavior such as aimless walking or pressing the head against a wall. Keep it well away from paddocks and hay.
Rabbits Caution
The same liver-damaging alkaloids run through it, so never offer dusty miller as forage. A nibble from a curious rabbit rarely does harm, but this is no green to stock in the hutch.
Livestock Severe
Cattle, goats, and sheep face the steepest danger since they graze it fresh or eat it dried in hay, where the bitter taste fades away. Steady feeding pushes toward liver failure, weight loss, and photosensitive skin, so keep it clear of pastures and stored feed.
Birds Caution
Treat dusty miller as strictly off-limits for pet birds and poultry. The pyrrolizidine alkaloids that harm mammals hit a bird's liver just as hard, so never let it turn into a snack.
People Caution
Nothing on this plant is grown to eat. Swallowing it in any amount can strain the liver through those 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
Almost all dusty miller on the market traces to a handful of named picks, sorted mainly by leaf shape and how tall they climb. Here are the ones you are most likely to spot.
Silver Dust
The runaway favorite, a tidy 10 to 12 inch plant grown for its lacy, deeply cut silver-white leaves.
Cirrus
A lower 8 inch mound that swaps the typical lacy cut for broad, rounded, undivided silver leaves.
New Look
A compact 10 inch pick carrying large, broad, felted leaves that read as solid silver from across the bed.
Candicans
The big one of the group at 16 to 24 inches, stacking bold lobed leaves onto a fuller frame.
How to propagate
Raise dusty miller from seed each spring, or root cuttings to carry a favorite plant straight 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
Get seed going indoors well in advance, around 10 to 15 weeks before your last frost. Light wakes this seed up, so press it onto the surface, leave it uncovered, and hold the tray at 68°F to 77°F (20°C to 25°C). Sprouts break through in roughly two weeks, and the young plants head outdoors once frost danger lifts.
Stem cuttingsModerate
Take cuttings in fall to overwinter under glass in cold climates · Several weeks to root
Cuttings are the move for rescuing a plant through a hard winter. Take them in fall and root them under glass, which runs several weeks, then nurse the young plants along into spring instead of handing the parent over to frost.
Myths
Dusty miller is only a problem for livestock and stays perfectly safe around cats and dogs.
Every ragwort and Senecio relative carries pyrrolizidine alkaloids, which lands the plant on the toxic list for cats, dogs, and horses alike. The danger to a household pet runs smaller and usually stops at a mild stomach upset, but it is not a non-toxic plant, and steady nibbling can still wear on the liver.
Animals always steer clear of dusty miller because of its bitter taste.
Fresh, the plant tastes bitter enough that most animals skip it whenever better food sits nearby. That safeguard collapses once forage runs short or the plant dries down into hay, where the bitter edge drops away and horses no longer reliably turn it down.