Ornamental · Caryophyllaceae
Carnation
Dianthus caryophyllus
Offer it cool air, full sun, and sharp drainage, and the carnation thanks you with fragrant, ruffled bloom.
Full sun
USDA 4–9
0–4 ft · 0.2–1.2 m
Overview
Carnations, along with their relatives the garden pinks, sit within the dianthus family, treasured for hundreds of years for their ruffled, clove-scented flowers. You'll find everything from short cushions only a few inches high to long-stemmed border kinds made for cutting, which means there's a shape for the edge of a bed and another for a vase on the table.
At their core these are cool-weather plants, most content in full sun with their roots tucked into gritty, fast-draining soil. They tilt toward alkaline ground and happily accept a pH anywhere from 6.0 to 8.0, a preference that sets them apart from most of their neighbors in the border.
They're a forgiving plant to grow, simply short-lived, easing away after a few seasons unless you keep a few young ones coming along. Feed them with a light hand and keep their crowns dry, and they'll give you weeks of fragrant bloom from late spring into summer.
Care
The short version: give them full sun, cool conditions, and gritty, well-drained soil that leans neutral to alkaline. Keep the soil evenly moist yet never soggy, feed only lightly, and snip off the spent blooms to keep fresh flowers arriving.
Light
Carnations love full sun, a solid six hours or more each day, which is what lets them bloom freely and stand tall without leaning over. Where summers grow hot they'll happily accept a bit of afternoon shade, and that small mercy also helps them weather the heat they'd rather avoid.
Water
Aim for soil that stays evenly moist but never soggy, and offer a drink through any long dry stretch. Wet roots are the quickest road to crown rot, so let the surface dry between waterings and keep the crown itself on the drier side.
Soil
Settle them into gritty, well-drained loam with a little organic matter mixed through. Carnations are unusual in their fondness for neutral to slightly alkaline ground, a pH of 6.0 to 8.0, and sharp drainage matters far more to them than rich feeding.
Humidity
Plain outdoor air suits them perfectly, so there's no figure you need to chase. Good airflow matters more than humidity, because crowded, damp foliage is exactly what lets rust take hold.
Feeding
Offer only light feeding across the growing season, and quiet the urge to give more. An overfed plant turns floppy and gappy, putting out weak stems in place of the flowers you were hoping for.
Pruning
Snip away the spent blooms to keep new ones arriving, and pinch off the growing tips early to coax bushier growth. Once the main flush is done, shear the mat-forming pinks back and you'll often be rewarded with a little repeat bloom.
Size & spacing
These plants stretch from low cushions around 6 inches (15 cm) tall up to border kinds touching 4 feet (120 cm), spreading 6 to 30 inches (15 to 76 cm) wide. Leave each one a little breathing room so the air moves freely and rust keeps its distance.
When to plant
Carnations move with the cooler part of the season, and that makes them easy to plan around. Sow seed indoors in late winter, move plants outside in spring once hard frost is behind you, and watch for fragrant bloom from late spring through summer, drawn out longer each time you deadhead.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring, about 8 weeks before last frost
- Plant: Spring after danger of hard frost; mat-forming pinks can also be set out in early spring
- Harvest: Late spring through summer (roughly May to July), prolonged by deadheading
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Nearly all carnation troubles begin either at the roots or in the heat, and the good news is they're easy to catch early. Keep a friendly eye on the crown, the lower stems, and the fresh growth, and you can step in long before a small issue grows. Find what matches below, then act while your help still counts.
A dark, mushy stem base while the plant flops over
What you're seeing is crown or root rot, which sets in when the soil stays too wet, most often through a soggy winter. Once the crown has gone soft and dark, that plant can't be brought back, so lift it gently and let it go. Take heart, though: sort out the drainage and ease up on watering, and the next planting has every chance.
Fix:
- Remove and discard severely affected plants
- Improve soil drainage
- Reduce watering and avoid wet, soggy soil
Rusty orange spots dotting the leaves and stems
Those marks are rust, a fungus that moves in when leaves stay damp and the air sits still. Don't worry, it's manageable: pick off the spotted leaves the moment you notice them, open up some space between your plants, and water at the soil so the foliage stays dry. The plant will carry on just fine.
Fix:
- Remove and discard affected foliage
- Improve air circulation by spacing plants
- Avoid overhead watering to keep foliage dry
Leaves yellowing and fading when summer turns hot
Heat is hard on carnations, so a plant slipping during a warm stretch is almost always just heat stress, not a pest or a disease. The fix is gentle: offer it some afternoon shade, keep the soil steadily moist through the hottest days, and if your summers run warm, lean on heat-tolerant pinks like the cheddar types next time.
Fix:
- Provide afternoon shade in hot regions
- Maintain even soil moisture during heat
- Choose heat-tolerant pinks such as cheddar pinks in warm climates
Twisted new shoots covered in tiny bugs
Those little soft-bodied insects gathering on the buds and stems are aphids, and the sticky coating they leave is honeydew. They're easy to deal with: knock them loose with a firm spray of water, trim away any shoots that are badly covered, and turn to insecticidal soap if a few keep returning. Feed with a light hand too, because tender new growth is just what tempts them.
Fix:
- Spray plants with a strong stream of water
- Remove heavily infested shoots
- Use insecticidal soap if needed
Toxicity
Carnations are only mildly toxic, which makes them a low-worry plant to share your home with. A nosy cat or dog that chews a leaf might have a short-lived upset stomach, and the sap can leave a mild rash, but the petals are gentle enough to serve as an edible garnish for people. Keep pets from treating the foliage as a snack and there's very little to concern you.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
Should a cat sample the leaves or flowers, you might see some drooling, vomiting, or a spell of diarrhea, and contact with the sap can bring on a mild rash. These reactions stay mild and usually settle on their own, so try not to panic.
Dogs Mild
A dog tends to respond in the same gentle way, perhaps a touch of vomiting or a loose stool after a nibble, and now and then a little skin irritation from the sap. None of it is dangerous, though a check-in with your vet makes sense if it lingers.
Horses Caution
No specific cases of poisoning in horses have been recorded, yet that same mild irritant could unsettle the stomach. To stay on the safe side, simply keep them from grazing on it.
Rabbits Caution
There's nothing to suggest rabbits come to harm from it, but the plant isn't food for them either, so it's kindest to leave it off their menu.
Livestock Caution
No poisoning of cattle, goats, or sheep from carnations has been documented, though the irritant compound might still bring on a mild stomach upset if they graze a patch. A little caution goes a long way here.
Birds Caution
Carnations carry no warning as a bird hazard, but since so little is known about how they affect birds, it's the gentler choice to keep pet birds clear of the foliage.
People Petals safe
Good news for you: the petals are edible and often appear as a garnish, so the plant holds no real risk to people. The one small thing is that the sap may leave sensitive skin a little irritated, so give your hands a rinse after a long spell of handling.
Sap may cause mild skin irritation in sensitive people; wash hands after handling.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Carnations and pinks arrive in hundreds of guises, from tall florist kinds to low fragrant mats. A handful, though, are well worth getting to know by name.
Clarion
A border carnation that holds clear yellow double flowers on sturdy upright stems rising above gray-silver leaves.
Bath's Pink
A mat-forming cheddar pink whose fragrant fringed soft-pink blooms take heat, humidity, and drought in stride better than most dianthus.
Firewitch
A cheddar pink loved for bold magenta single flowers, blue-gray leaves, a strong scent, and genuine cold hardiness.
How to propagate
Carnations don't live long, so it helps to keep a fresh supply on the way, and happily that's simple to do, whether you divide an aging clump or root a few cuttings.
Stem cuttingsModerate
Take terminal cuttings in early summer · Several weeks to root
When you want an exact copy of a named cultivar, cuttings are your friend, because those types won't come true from seed. Clip a healthy shoot tip in early summer, settle it in moist mix, and after several weeks to root you'll have a plant that matches its parent.
DivisionEasy
Early spring as new growth begins · One growing season
Since carnations don't live long, dividing the clumps every few years is an easy way to keep them going strong. Lift and split them in early spring as new growth appears, and the divisions find their feet over a single growing season.
Myths
Carnations are tough plants that thrive in hot summer climates.
The truth runs the opposite direction. Carnations long for cool weather and labor through high heat, which makes them an iffy choice for hot southern gardens. If your summers run warm, lean on heat-tolerant pinks such as the cheddar types.
Feed carnations heavily and you'll get the best blooms.
Heap on the fertilizer and what you get is tall, floppy stems with bare gaps, not extra flowers. Go easy at feeding time and you'll see the sturdiest growth and the finest bloom.