How to Plant, Grow and Care For Carnation Flowers
Carnations are ornamental garden staples, filling containers or beds with masses of intricate flowers. Follow this guide to find out how to grow and care for carnations in your own backyard.
When I hear the word carnation, I’m immediately transported several years back to a time when traditional plants (those that populated my great-grandmother’s garden) ruled the nursery. It seemed like anything bright red and somewhat reminiscent of the holidays took center stage, from bright red carnations to waxy anthuriums.
But I do admit that this memory doesn’t completely do these plants justice. They are not old-fashioned relics, certainly not with the number of stunning cultivars on the market today. Rather, they are intricate plants that deserve a prominent space in every cut flower garden and patio display.
If you want to start your carnation growing journey, rather than spending a fortune buying fresh-cut flowers from the store, follow this guide to get it right.
Carnation Plant Overview
Plant Type Perennial
Species Dianthus caryophyllus
Native Area Mediterranean
Hardiness Zones 7-10
Exposure Full sun to partial shade
Height Up to 30”
Watering Requirements Low to moderate
Soil Type Slightly sandy alkaline soil
Pests & Diseases Aphids, mites, rust, botrytis
The classic carnation is a part of the Dianthus genus, containing a range of popular garden plants, including Sweet William (Dianthus barbatus) and Garden Pinks (Dianthus plumarius). They are known for their adorable frilled petals and often spicy scents, lending carnations their other common name – clove pink.
The genus name comes from the Ancient Greek words dios (meaning divine) and anthos (meaning flower), giving a small hint at the importance of these flowers throughout history. The species was named Dianthus caryophyllus by the ‘father of modern taxonomy’ Carl Linnaeus in 1753 and has remained unchanged since, escaping any potential botanical confusion. The specific epithet caryophyllus refers to the clove-like scent of the flower (a previous genus name of the clove plant).
Cultivated for thousands of years, carnations have inspired artists, poets, and gardeners with their delicate flowers. Like other flowers, they have several meanings depending on your chosen color, from admiration (red) to good luck (white). They are also the flower most commonly gifted on Mother’s Day, dating back to the early 1900s.
Due to their ubiquity, some gardeners may see these plants as somewhat old-fashioned. However, considering the wide range of unique cultivars that are available, it’s easy to find a carnation that suits your garden without looking too traditional.
Carnations are typically grown as long-term perennials, although they can be considered short-lived or even annuals depending on your local climate. The right environment and plenty of love are key components in extending their lifespan – if that is your goal.
There are many different cultivars to choose from, thanks to the expertise of growers in the industry. The pink, white, and red varieties are the most sought-after (hence the common name clove pinks), but you can also find carnations in purple, yellow and, a personal favorite, bi-colors. Each flower sports the delicate frilled petals that make these plants so famous, along with a sweet clover scent (although some cultivars may lose their scent).
Carnation plants typically grow to about a foot and a half tall, with some variation depending on your chosen type. When they aren’t blooming from late spring to summer, you can enjoy the blue-green needle foliage that sets the stage for the later carpet of flowers. In cold climates, they can be cut back and protected over winter to emerge again the following spring.
Where To Buy Carnations
Based on your region, carnations are typically planted from seed in late winter or early spring. If you’re searching for a specific cultivar, shopping online for the widest possible availability is best.
But if you prefer a wide variety and a kaleidoscope of blooms, look for mixed seed packets like the Chabaud Blend Carnation Seeds from Botanical Interests.
If you want fast flowers from these plants (in other words, flowers in the first year), start your seeds indoors around 8 or 10 weeks before the last frost date in your region. If you’re unsure, check your local resources to determine the perfect time to sow.
Giving the plants this early protection indoors will help them establish quickly, potentially producing the first flush of blooms in summer. If you prefer to direct sow, you can once temperatures have warmed, but you’ll probably have to wait till year two to see your first flowers.
Grab a strong seed tray and fill it with a light seedling mix. Avoid dense mixes – you want to provide as little resistance to root growth as possible while still encouraging the development of a strong root system. If it’s particularly cold in your region, you can supercharge growth with a seed starting heat mat that will help boost germination rates.
If you’ve never grown from seed before and don’t have the right tools on hand, this Start My Seeds Bundle comes with everything you need to get sowing.
Sprinkle your carnation seeds on top of the soil finely. Cover with a light layer of seedling mix or a layer of vermiculite, ensuring the seeds aren’t planted too deeply. Water very gently with a watering can to avoid displacing the seeds.
Next, you must keep the heat in and create the perfect environment for quick and strong growth. To do this, you can either cover your tray with a germination dome or use a clear plastic bag. The benefit of the dome is that the plastic won’t touch the early leaves, but you can also use skewers to hold the plastic up and away from the plants if needed.
Keep the soil lightly moist but never soggy for the first few weeks. You won’t need to water very often as the dome will help maintain moisture. However, removing the lid every few days is best to allow air to flow around the seedlings and limit your chances of mold growth.
Your little carnation seeds should germinate within a couple of days in the right conditions. In the early stages, remove the weaker performing growth to give the strong seedlings plenty of space to expand. Keep them warm and well-watered until you spot at least two sets of leaves.
Once temperatures have warmed outdoors (about two weeks after your last frost date) and your carnations are around 5 inches tall, they are ready to head outdoors. You may want to leave them outside in their trays for a couple of days before planting them in the ground to allow them to adjust to their new conditions.
When you’re ready, prep your planting site, ensuring the soil is rich and well-draining. Make small holes and transplant your seedlings, leaving about 10 inches of space between each plant. When planting in containers, choose a well-draining potting mix and ensure your container has enough drainage holes.
How to Grow
Carnations may look high-maintenance, but they are not tricky to care for when they are planted in the right spot. If you want them to flower profusely and to continue to flower year after year, there are a few essential steps to follow.
A full sun spot is best to get the most out of your carnations. Plenty of direct sunlight will give the plants the energy they need to push out carpets of flowers in summer. Aim for around 6 hours of direct sun, preferably slightly longer if you live in a cooler climate.
If you live in a warmer climate with intense summers, your carnations will benefit from some afternoon shade. Although they love the sun, they will struggle to bloom when scorched by searing midday light. In other areas, avoid partial shade to keep your plants blooming all season long.
Carnations are not too demanding regarding water once they are established. But in the early stages of growth, when young roots spread into the soil, regular watering is essential to create strong foundations for later flowering.
In spring, soon after planting, water around once per week, thoroughly soaking the soil to push the roots to spread downwards and outwards. The soil should never be waterlogged, but the right soil texture will help drain any excess away before it has a chance to impact the roots.
Toward the end of spring, when the plants are established, they are considered somewhat drought tolerant. You can allow the soil to dry out slightly between waterings without any significant signs of struggle. When temperatures are high, give them an extra drink to avoid heat stress – especially during peak flowering times.
Watering should be top of mind if you’ve planted your carnations in pots. The soil in smaller containers will dry out quickly, especially if the pots are kept in full sun. You must water every few days rather than once a week to stop the soil from becoming too dry.
When planting Dianthus caryophyllus, well-draining soil is an absolute must. These plants are prone to root rot and crown rot if the soil retains too much moisture. In other words, if you have heavy clay soil in your garden, you must make some serious amendments or plant in containers instead.
These plants will grow best in slightly sandy soil with a neutral or alkaline pH. Don’t worry too much about amending your soil to change the pH unless it is very acidic – the plants can typically adjust well. It’s also best to amend your soil with compost to boost organic matter and improve soil structure.
Carnations have slightly different climate tolerances depending on which cultivar you are growing. But they generally grow best in USDA Zones 6 to 10. They prefer warmer temperatures and can’t handle extreme cold well, but they also don’t perform well in extreme heat.
Thanks to their Mediterranean origins, carnations are also accustomed to dry air. They can handle some humidity, but this will increase your chances of fungal disease and other growth problems. Keep them in a sheltered area to protect the stems and blooms.
Although they are not reliant on fertilizer to grow successfully, carnations will perform better over the years when nutrients in the soil are regularly replaced. A slow-release organic fertilizer will cover all the nutrients the plants need to grow and flower, limiting your risk of burning the roots (if used correctly).
Always follow the instructions on your chosen packaging exactly, feeding once per year with a potential extra boost in summer if needed. Overfertilizing will damage the roots, ultimately stunting growth rather than helping it.
Along with these regular tasks, there are a few additional chores to consider to keep your carnations looking their best this season and the next.
The first is deadheading. Removing spent flowers as soon as they start to die back will direct the plant’s energy toward producing new blooms. It also looks much tidier, maintaining the impressive flowering carpet throughout the season rather than a few weeks.
If you’re growing a taller cultivar, you may also want to consider supporting weak stems. This will keep the foliage and flowers completely off the ground and growing upright, limiting issues with pests and diseases at the same time. As these plants are relatively small (in comparison to some other ornamental giants), you won’t need very large stakes.
Finally, when frosty conditions start to loom at the end of the season, cut your plants back and cover the soil with a layer of mulch to insulate the roots. Ensure you keep your chosen mulching material away from the crown to prevent rot.
It’s important to mention that although mulching can help retain moisture in the soil and keep weeds down, it does come with risks for carnations. Layers of mulch around the base of the plant in spring and summer can encourage crown and root rot if there’s no gap between the mulch and the plant.
If you want to grow more carnations in your garden, you have a wealth of options to choose from. Carnations can be propagated by division, cuttings, and seeds, depending on the plant’s growth at the time of propagation.
Propagating By Division
Dividing carnations is not only a useful practice to grow your collection for free. It also allows you to rejuvenate tired or overcrowded plants that may not perform as well as they used to. This is usually done every three years or so for performance purposes, but you can divide whenever your plant is large enough to split successfully.
Division of carnations is best done in the fall. Aim for the gap between the end of flowering and any severe temperature drops to get them back in the ground before frost. All you need is a spade and a clean pair of shears.
With your spade, mark a ring around the edge of the plant and dig straight down into the soil. Once your spade is in, lift the root system from the bottom, continuing around the edges until the plant is released. While you may snag some external roots, it’s important to keep as many roots intact as you can.
Lift the plant out of the ground completely and remove some soil around the roots. Identify your divisions and either pull the plant apart by hand or cut into the roots with your shears. Keep a healthy number of roots on each section and remove any parts of the plant that look diminished or diseased.
Replant each section back into the garden with new spacing between them. Avoid burying the crown too deep as this can lead to rot – at or just above the soil line is ideal.
Propagating From Cuttings
If you’re willing to wait a little longer to see results from your propagation efforts, you can produce far more new plants at once by propagating from cuttings. This is usually done in summer when growth is most vigorous, as long as temperatures are not too high.
Start by choosing stems (preferably without blooms) that are healthy and damage-free. Your cuttings should be around 4 or 5 inches long with several sets of leaves along the stem. Grab a sharp pair of shears and trim the cutting just below a node, removing the bottom sets of leaves to expose the stem.
After cutting, you can dust the end with rooting hormone. This substance stimulates root growth and protects cuttings from disease, but there is still potential for rooting without this step.
Plant your prepared cuttings into a propagating mix – I like to use a mixture of potting soil or coir and sand for Mediterranean plants like carnations or lavender. You can plant several cuttings in the same container or tray, but give them enough space to grow without the leaves touching. Water as soon as you’re finished planting, focusing the stream of water on the soil.
Keep the container in a warm and bright area but away from direct sunlight. Once root growth appears, you can transplant them into individual containers and, later, out into the garden.
Propagating From Seed
To propagate from seed, avoid deadheading the last few flowers at the end of the season. Wait until seed heads form and either leave them to dry on the plant or trim them and bring them indoors to continue drying.
Once completely dry, place the seed heads inside a bag and shake the stems to remove the small seeds. This will help you catch as many seeds as possible. You can also leave them outdoors to spread naturally (if your variety does) potentially, but saving the seeds will give you far more control over next year’s growth.
Once you’ve collected your seeds, save them to plant according to the instructions above when spring arrives.
Carnations are far more than ornamental garden plants. They grow well in patio containers (as long as they have enough light) and make good companions for a number of other plants. They suit the popular cottage garden aesthetic, too, if an abundance of informal blooms is what you’re looking for.
Carnations are staples of cut flower gardens, beloved for their delicate blooms, and the petals are even edible. I’ve used them as decoration in a few deserts and cocktails, with the spicy flavor providing quite a surprising contrast to sweet dishes and drinks.
Carnations are not fussy or dramatic. But like all garden plants, they are susceptible to a few problems. Take a look at this list to know what to watch out for:
Carnations attract mites, thrips, and dreaded aphids. Remove infestations with insecticidal soap as you spot them to stop them from spreading.
Watch for fungal diseases like botrytis, rust, and a few types of wilt, including fusarium wilt. Yellowing, wilting, and general discoloration indicate an issue that needs to be addressed as soon as possible. Remove infected growth to control the spread and limit overhead watering and overcrowding to limit the chances of disease problems.
Lack of Blooms
Shade is usually responsible for the lack of blooms. Plant in a sunny area and keep up with watering to encourage more blooms.
Low light levels can also lead to stunted growth, although this is often a sign of another issue. Look for signs of crown or root rot and check for overgrown roots for plants in containers.
Aging plants can become leggy over time. Lift and divide to reinvigorate them. Plants can also become leggy when temperatures are too high, requiring some protection during hot summer days.
Frequently Asked Questions
What do carnations smell like?
Carnations are also known as clove pinks, alluding to their scent. The flowers have a slightly spicy fragrance reminiscent of cloves, although some types will have a stronger scent than others.
What do carnation flowers mean?
Carnation blooms have different meanings depending on the color of the flower. Red flowers are typically associated with admiration, while white flowers represent good luck. Pink carnations represent gratitude and are often gifted on Mother’s Day.
Will carnations grow in shade?
Although they can tolerate some partial shade in hot climates, it’s far better to grow carnations in full sun for the strongest possible flowering.
Are carnations perennials?
In the right conditions, carnations are typically grown as perennials. They will perform better when divided every few years.
Are carnations toxic to pets?
Although the petals are edible for humans, carnations are mildly toxic to pets. It’s best to keep them away from any animals to avoid negative gastrointestinal reactions.