We are in love with cosmos. Here are some of the reasons we grow cosmos as a cut flower on our flower farm!.
I’ve always loved the soft look of cosmos growing in our Nova Scotian gardens. With their lacy leaves, they look so delicate, and they look great in a bouquet with other leaves.
Cosmos is a great flower to cut, and it was one of the most popular things we used to fill out our farmhouse bouquets last year. They were airy and graceful and added a wonderful soft touch to the bouquets.
They come in a variety of colors and shapes, singles and doubles, some with interesting edges. Cosmos contributed to that wild flower and casual look that we love to show in our bouquets.
With their delicate, daisy-like blooms in a rainbow of colors, cosmos are one of the most charming and rewarding annual flowers you can grow. Not only do these hardy plants produce abundant flowers all season long, but cosmos also make fantastic fresh cut flowers. Here’s an in-depth look at why cosmos are so ideal as a cut flower and how to grow and use them for gorgeous arrangements and bouquets.
An Overview of Cosmos as Cut Flowers
There are several reasons why cosmos are considered one of the best choices for cut flower gardens:
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They are easy to grow, undemanding, and bloom prolifically from early summer until fall frost.
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The long slender stems work beautifully in both garden-style and vase arrangements.
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The blooms attract pollinators while resisting deer and other pests.
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Cosmos come in a diverse range of heights, colors, and flower forms.
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The cut flowers have excellent vase life lasting up to 10 days with proper care.
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The more you cut cosmos, the more blooms they will produce all season.
With proper planting and care, a small investment of cosmos seeds or starter plants can yield hundreds of fresh cut flowers for your home, events, or florist business. Keep reading to learn how to successfully grow and use cosmos as cut flowers.
Choosing the Best Cosmos Varieties for Cutting
With dozens of cosmos varieties to choose from, it helps to select ones suited for cut flowers. Consider height, bloom size, productivity, and color when planning your cosmos patch or row.
Tall cosmos varieties with long stems such as Cosmos bipinnatus and C. sulphureus typically reach 3-4 feet tall. They produce an abundance of slender-stemmed blooms ideal for cutting. Popular tall varieties include ‘Bright Lights’, ‘Sea Shells’, and ‘Sensation’.
Dwarf cosmos only grow 1-2 feet tall but the shorter stems work well in posies and hand-tied bouquets. Look for compact varieties like ‘Sonata’, ‘Cupcakes’, and ‘Rubenza’.
Large, double-flowered cosmos showcase pom pom-like fully double blooms. Try ‘Double Click’ for bicolor pink and white blooms on 30 inch stems.
Don’t overlook vibrant shades like the red-and-white bicolor ‘Double Click Cranberries’ or bold ‘Cosmic Orange’.
When and How to Plant Cosmos for Cut Flowers
Spring planting is recommended so cosmos have time to become established before peak summer heat. Sow seeds directly in the garden after all danger of frost, or get a head start by planting seedlings indoors 4-6 weeks before your area’s final expected frost.
Space seeds or young plants 12-18 inches apart in fertile, well-draining soil. Wide spacing prevents overcrowding and produces longer, cutting-quality stems.
Plant cosmos in full sun (at least 6 hours of direct sun daily). Garden beds amended with compost or manure work well. Cosmos also grow great in raised beds and containers.
Add trellising or staking if growing extra tall varieties prone to flopping over. Once flowering begins, harvest frequently for maximum stem production.
How to Cut Cosmos Flowers for Gorgeous Arrangements
Follow these steps for beautiful, long-lasting cosmos cut flowers:
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Use clean, sharp pruners or flower scissors. Sterilize tools between plants to prevent disease spread.
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Harvest in the early morning when stems are hydrated and flowers are just opening.
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Select stems with firm buds that have begun showing color but haven’t fully opened yet.
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Make cuts at an angle just above a set of leaves or side shoots.
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Place freshly cut stems directly in water. Recut 1-2 inches off the stem and add floral preservative.
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Strip lower leaves that would sit below the water line. Leave some upper foliage to frame blooms.
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Display cosmos out of direct sun for longest vase life. Change water and recut stems every 2-3 days.
Extending the Vase Life of Cosmos Cut Flowers
Follow proper hydration and post-harvest care to enjoy cosmos blooms for up to 10 days in arrangements. Here are some tips:
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Use lukewarm water and commercial flower foods/preservatives.
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Remove faded flowers to direct energy to new buds.
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Mist blossoms occasionally with fresh water.
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Keep cosmos in a cool spot out of drafts or direct sunlight.
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Re-cut stems and replace water every 2-3 days.
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Use materials like alum powder or floral sleeves to prolong vase life.
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Consider treatments like searing stem ends or wilting clusters for 8 hours before arranging.
Creative Uses for Cosmos as Cut Flowers
The delicate, airy look of cosmos adds beauty and whimsy to all types of floral designs.
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Pair different cosmos colors and varieties together in fresh bouquet arrangements.
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Mix cosmos stems with garden roses, zinnias, and dahlias in lush, bountiful centerpieces.
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Weave slender cosmos blooms into bridal bouquets, corsages, boutonnieres.
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Showcase cosmos in bud vases, posies, or hand-tied wraps.
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Drift cosmos through centerpiece foundations for organic texture.
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Use cosmos as filler around focal flowers like sunflowers or dahlias.
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Dry cosmos blossoms to preserve them for everlasting arrangements.
Continual Harvest for Non-Stop Blooms
One of the best things about cosmos is that the more frequently you cut the flowers, the more they will bloom until fall.
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Begin harvesting cosmos flowers when 60% of the buds on a stem are open.
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Always leave at least one fully opened flower per stem when cutting.
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Make cuts just above a set of leaves or side shoot junction.
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Regularly deadhead spent blossoms to the next lower flower bud.
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Fertilize occasionally and water during drought to support new growth.
With simple, continual harvesting you can amass gorgeous cosmos stems by the armful for all your floral creations.
Cosmos Add Charm and Whimsy to Any Flower Design
With their delicate, colorful blooms and carefree growth habit, it’s easy to see why cosmos make fantastic cut flowers. These beautiful annuals reward growers with an abundant harvest of slender-stemmed flowers ideal for mixed bouquets, garden-inspired centerpieces, and any floral arrangement. For best results, provide cosmos with sun, space, and regular cutting. Your floral creations will flourish with the addition of these charming, prolific blooms.
Do Cosmos Come Back Every Year?
Cosmos are an annual flower, so you need to replant each year for best success. Some plants from last year’s crop have grown back as volunteers, which is always fun. But every year we start our new crop of seedlings indoors to plant outside in the spring.
You can also direct sow into your garden once the risk of frost has passed. We do not use this method due to high our weed pressure in the field. We’ve also had late frosts in June, which hurt these tender seedlings.
We start our seedlings in soilless mix under lights around March or April. For the best growth, we plant them about 1/4 inch deep and put them on a heat mat until they start to grow roots. They remain under grow lights until ready to be hardened off and planted out. Then they are planted out into landscape fabric with burned holes 12” apart. They do really well in the landscape fabric.
Do Cosmos Last As Cut Flowers?
Columbines need to be cut at the right time if you want them to last as cut flowers. The best stage to harvest the blooms is when the buds are coloured but not yet opened fully. An example of this is in the picture just above.
You can watch them open up more in the vase, and if you cut them at the right time, they will last longer. If they are cut before the buds show colour, the buds will not open. If you want the flowers to open, you need to pay close attention to the stage of the buds.
These flowers won’t last as long in a bouquet if you cut the stems when they’re fully open, and it can be sad when the petals start to fall off. They look beautiful at this point, but they might not last as long as you’d like.
I’ve also used cosmos just for the leaves, before the buds even started to open, because I love how light and full the soft leaves are. I only wanted the greenery in this case, which was lovely. I did this last year when I ran out of good fillers, and the cosmos came through!
Best Cosmos to Grow, and which ones not to grow. Flower Farming
FAQ
Do cosmos last as cut flowers?
Do cosmos do well in a vase?
How to make cosmos last longer in a vase?
Can Cosmos be used for cutting garden flowers?
Cut-flower expert and nursery owner Sarah Raven is a huge fan of using cosmos as cutting garden flowers. ‘Cosmos bipinnatus lasts 10 days in the vase, produces two buckets of cut flowers a week from a 3ft (90cm) x 3ft (90cm) patch, and does so from late June until November,’ she says.
Do Cosmos stop blooming?
If plants are not regularly harvested or deadheaded, they will stop blooming. “Afternoon White” Cosmos Nearly every type of Cosmos can be used to cut flower use, but there are some varieties that have been bred specifically for cut flower use, rather than ornamental use. Some Cosmos have “single” petals, while other are “double” petals.
Are Cosmos plants good for Posies?
If you love having bunches of flowers in the home, cosmos are a great plant to grow. The taller varieties generally have longer flower stems, but even the compact types are good for posies. Grow them from seed and plant them out all over the garden to pick the flowers all summer long.
What flowers go well with Cosmos flowers?
Image: AdobeStock Mix cut cosmos flowers with roses and lady’s mantle, the feathery cosmos foliage helps to fill the arrangement with texture and soft hues of green, so you need very little extra greenery and have a charming bouquet, prefect for the lunch table or an impromptu gift for a friend.
Are Cosmos easy to grow?
Cosmos are one of the easiest, most rewarding flowers you can grow in your garden. Their simple, open flowers have a friendly, smiley, summery demeanor and can be planted in beds, borders, pots and containers all around your garden with simply stunning results. Cosmos are one of the easiest, most rewarding flowers you can grow in your garden.
Are sulfer Cosmos good for cut flowers?
As a bonus, Cosmos foliage is beautiful and useful in bouquets/arrangements. Regular Cosmos have lacy, delicate foliage, while Sulfer Cosmos have bold, sturdy foliage (pictured below). When growing Sulfer Cosmos, I find myself using the foliage more than the blooms! Here are a few of my favorite Cosmos to grow for cut flower use: