How to grow cornflowers?

How To Grow Cornflowers From Seed.

‘Blue Boy’ Cornflowers.

I would never be without cornflowers in the Higgledy Garden. Not only are they drop dead gorgeous and immensely productive but they are also very simple to grow and look after.

Cornflowers ‘Black Ball’

Cornflowers are what we can call, ‘cut and come again’ flowers…if you cut them above a leaf node then the little star will produce more flowers for you…albeit on slightly shorter stems. It’s a good plan to have a good proportion of your cut flower patch made up of ‘cut and come again flowers’….this way you will have flowers from May until the frosts, even from the smallest patch.

‘Boy Boy’ are great with any orange flowers you can get your mitts on.

How To Grow Cornflowers From Seed.

*First of all you need to find a space for them in free draining soil in full sun.

*The soil doesn’t need to be rich, in fact Blue boy cornflowers are rather delighted to be in the presence of poor soil. (Treat em mean keep em keen.)

*Rake the soil down to a fine tilth. By this I mean rake it down to small pieces no bigger than a marble.

*I make an September sowing and then a spring sowing…not sowing outside until mid April when the soil has warmed up.

*I tend to sow the seeds into three rows about a foot apart. This way when the plants grow it is easy to reach the middle from either side.

*sow the seeds thinly. A pack of Higgledy Garden seeds should be enough to cover twenty meters of a single row without any bother. Don’t do as I did on my first attempt many moons ago to use a whole packet of seeds in about three feet. Silly man.

*Prewater your seed drills…this stops the seeds from being washed away by watering afterwards.

*In three weeks you will see the little munchkins wiggling their way up out of the ground…thin them to about a foot apart. If you are careful you can move the seedlings if you don’t disturb the roots too much.

*Keep the bed weed free.

*Don’t let the ground dry out too much whilst they are growing.

*I put some pea netting up at a height of about two foot and let the plants grow through it. That way they get support, high winds can flatten a bed in no time….as I have discovered….grrrrrrrr



(Centaurea cyanus) It’s probably not the norm for most people to delve into the nomenclature of their flowers but we think it’s pretty darn cool. Because guess what? Those Latin names, they all mean something! But first things first… these 2-3′ brilliant icy blue double-flowered beauties brought to America in the 17th cent from England were once a common field weed (hence another of their names “cornflower”) but are now quite hard to find in the wild. Edible petals retain their color after drying and can be used as a compress for your tired, swollen eyes and as an ingredient for a facial steam. Fresh or dried they are lovely added to salads, tea mixes, cake decorations and anywhere a touch of blue would be welcomed including your watercolor paintings. They are a drought-tolerant self-sowing annual and will happily naturalize. An attractor of bees and butterflies and, as you may gather from the Latin name, many a fine story. According to Greek legend, Cyanus was a youth smitten with Chloris (Flora), the goddess of flowers. Such was his devotion that the lad spent every moment gathering blue flowers for her alter, neglecting his own health and alas, perished in a field of millet. In a show of love, she then turned him into the flower itself which just so happens to grow wonderfully among grains. (hence it’s persistence in romantic lore to this day.) As for Centaurea, this derives from the great Centaur Chiron who was gravely wounded by an arrow dipped in the toxic blood of the Hydra. He cured his festering wound by making a compress of bachelor button petals. There’s so much more! I will leave it to you to gather (or not) more stories as you gaze upon these lovely, long-lasting, pollinator-attracting and cold-tolerant beauties.
60 days. UO

Packet: 75 seeds

Cornflower (Centaurea cyanus)

Cornflowers are extremely colourful hardy annuals. They look great in beds and borders, especially when part of an annual bedding display or a cottage garden, flowering from late spring and summer into autumn.

Cornflowers are also commonly known as ‘bachelor’s buttons’ – and more than a dozen other common names. They make excellent cut flowers and attract bees and butterflies and other pollinating and beneficial insects.

Although blue is the most common colour; white, red, pink and purple varieties are also available.

How to grow cornflowers

Cornflowers grow and flower best in sunny positions. They need a fertile soil enriched with lots of organic matter, which holds plenty of moisture in spring and summer, doesn’t dry out or become waterlogged.

Cornflower varieties

  • Black Ball Rich chocolate shade, that look almost black.
  • Blue Diadem Large, deep blue double flowers.
  • Classic Fantastic Various shades of blue, with frosted white edges.
  • Jubilee Gem Large, deep blue double flowers.
  • Polka Dot Mix Shorter plants with flowers in a range of colours – white, pinks, blues and reds.

Sowing cornflowers

Sow seeds from March to May outdoors for flowers from June to September, or sow during August and September to flower slightly earlier the following year.

Sow seeds thinly in finely raked, moist soil where you want the plants to flower, at a depth of 13mm (½in) covering the seeds lightly with soil. Water the soil during dry periods.

Thin the seedlings in stages to 15-23cm (6-9in) apart when they’re large enough to handle.

Planting cornflowers

You can buy young plants from garden centres, nurseries or mail order suppliers for planting in spring.

Dig over the planting area, incorporating lots of organic matter – such as compost or planting compost, especially if the soil is heavy clay or light, well-drained sandy soil. Dig a good sized hole big enough to easily accommodate the rootball.

Place the rootball in the planting hole and adjust the planting depth so that the crown of leaves is at soil level. Mix in more organic matter with the excavated soil and fill in the planting hole. Apply a general granular plant food over the soil around the plants and water in well.

Suggested planting locations and garden types

Flower borders and beds, patios, containers, city and courtyard gardens, cottage and informal gardens, cut flower garden.

How to care for cornflowers

Water plants whenever necessary to keep the soil or compost moist during spring and summer, as this will prolong flowering.

Remove any competing weeds while the plants are young and establishing.

Applying a balanced liquid plant food every couple of weeks in the growing season will also encourage more, bigger and better flowers.

Deadhead plants regularly to prolong their flowering period well into autumn.

Cornflowers are generally pest free.

Flowering season(s)

Spring, Summer, Autumn

Foliage season(s)

Spring, Summer, Autumn


Full sun

Soil type

Chalky, Clay, Loamy, Sandy

Soil pH


Soil moisture

Moist but well-drained

Ultimate height

Up to 75cm (30in)

Ultimate spread

Up to 30cm (12in)

Time to ultimate height

3-4 months


Common Name

cornflower, knapweed, star thistle


  • Sun
  • Rockery

Flowering Season

Summer, Spring


Widespread in the temperate zones, this genus in the daisy (Asteraceae) family commonly known as cornflower or knapweed encompasses around 450 species of annuals, perennials, and subshrubs. Though they are extremely variable, most species are readily identifiable by their pretty thistle-like flowerheads, which are produced over a long season. The flowers come in a range of colours, and most have feathery foliage, some with silvery grey leaves, that acts as a perfect foil for the attractive flowers. The genus was named for Chiron the Centaur, the Greek mythological figure famed for his healing powers, because some species have been used to treat wounds.


Plant size varies greatly, but common features are feathery, often pinnately lobed foliage, sometimes silver-grey, and an upright habit. While cornflowers are extremely variable, they all share similar flower characteristics, with the blooms emerging from a whorl of bracts, known as an involucre. The thistle-like flowerheads often have distinctly different inner and outer florets, with the outer florets having 5 narrow petals. Flower colours include white, yellow, pink, mauve, and blue.


Plant cornflowers in light well-drained soil in a sunny position. Good ventilation will lessen any mildew problems. Regular deadheading will keep the plants looking neat and tidy, and will encourage further flower production. Annuals such as the common cornflower (Centaurea cyanus) are raised from seed; perennials may be propagated by division or from softwood cuttings of non-flowering stems.

Gardening Australia suggests you check with your local authorities regarding the weed potential of any plants for your particular area.

© Global Book Publishing (Australia) Pty Ltd from Flora’s Gardening Cards


Cornflowers are fairly easy to grow and are a great flower for kids or beginners to include in their garden. They are a cheerful and attractive flower that is just as appealing to beneficial insect life in the garden as it is to the garden’s human inhabitants. Though most cornflowers are ‘cornflower blue’, they do actually come in a whole range of types and colours.

Growing cornflowers:

Cornflowers are grown from seed planted in the spring and they are best sown direct into the soil in which they are to grow. If you plant cornflower seeds between March and May then you will be treated to a lovely display between June and September.

Cornflowers prefer a site in full sun, in a well-drained soil. The soil does not need to be particularly fertile and in fact many varieties will actually flower better in an area where soil is less than perfectly nutritious.

When you are planting your cornflower seeds, make drills in the soil and water these before you sow the seeds. This is to prevent the seeds being washed away by the water. The cornflowers should pop up above the soil in around three weeks. Try to be careful not to disrupt the cornflowers’ delicate roots if you decide to move the small seedlings or thin them.

Cornflowers are best planted in a sheltered location, as if they are in a bed together then the whole lot can easily be flattened by a strong wind. Since they are fairly tall plants, some people choose to give them some support although this is not usually necessary.

Cornflowers welcome other company and will look lovely and bright when in a garden bed with marigolds or poppies or other vivid flowers. Cornflowers can be good for hiding the stems of roses and other tall shrubs.

You can pick cornflowers for use in floral displays. If you are careful to cut them just above a leaf node then they should produce more flowers for you, just on shorter stems, so these flowers can keep producing for you for the whole summer and perhaps even beyond. Cornflowers should be picked just before they are fully open when the centre of the flower is still slightly dipped inwards.

Why grow cornflowers in the garden?

Cornflowers really are a beautiful flower to look at. They are good value too since the display they create can keep on going for several months. Once established in a bed, cornflowers will self-seed and return year after year, bringing enduring cheer in a low maintenance area of the garden.

Cornflowers are a native UK plant and once grew with abandon across our farm fields, until herbicides used in farming made them very rare in the wild and confined them to our gardens.

Cornflower Plants In Containers: Can You Grow Bachelor’s Buttons In A Pot

There are both annual and perennial varieties of bachelor’s buttons, or Centaurea cyanus. The annual forms reseed themselves and the perennial types spread through stolons. Both make excellent cut flowers and specimens in a wildflower garden. Can you grow bachelor’s buttons in a pot? Growing bachelor’s buttons in containers provides that true blue color to offset and enhance other hues of foliage and flowers. All you really need is a color scheme, good soil, the correct container and a proper location.

Can You Grow Bachelor’s Buttons in a Pot?

Bachelor’s buttons, also known as cornflowers, have an unruly appeal which makes them naturals for the wildflower garden. However, they can show a little restraint and cornflower plants in containers will enhance any container display. Sowing the seeds indoors 6 weeks before you want to plant them out will provide you with large enough plants to work into your container color displays.

Seeds sown indoors will need to be thinned as soon as the plants get their first true leaves. Leave at least 2 inches between plants. When seedlings are large enough, harden them off outside, gradually. Directly after transplant, move the container to a medium light situation so as not to shock the plants. Over the next few days, gradually increase the light exposure. Then they will be ready to join a color display in a container.

Use well-draining soil and a container with several drainage holes. You may even use a soilless mix. Cornflower plants in containers prefer soil on the dry side, so the potting mix should be one which will not retain too much moisture.

Plant at the same level at which they were growing and water the medium well. Mix other annuals in with colors that will offset the brilliant blue and add some trailing plants at the edge for an elegant waterfall effect.

Lighting and exposure are important to ensure plenty of blooms. Growing bachelor’s buttons in containers successfully starts with the type of soil and good drainage but relies upon good sunlight exposure. Choose a location with full sun for best growth, although they can tolerate partial sun. Lower light situations will result in fewer flowers and leggy plants.

As the young plants mature, it is a good idea to pinch them back to force denser bachelor’s buttons and more buds.

Container Care for Bachelor’s Button Plants

Very little special container care for bachelor’s buttons is necessary. One of the biggest tips for growing bachelor’s buttons in containers is to keep the soil a little on the dry side. Water when the top inch of soil is dry to the touch. Give the plants a bit more water in high heat conditions.

Fertilize container plants with water soluble plant food once per month.

Bachelor’s buttons should be deadheaded for best appearance.

Few pests bother the plants and disease is usually confined to fungal issues which are easy to prevent by monitoring water usage.

When growing bachelor’s buttons in containers, be prepared for a short but glorious season. These wildflowers are mostly present in spring and early summer with the exception of the perennial forms. Plant now and enjoy a burst of sky blue color for a few months.

Flowers need not be showy or huge to make a statement. On his wedding day, John F. Kennedy wore a single small flower in his lapel. We know these simple flowers as bachelor’s (or bachelor) buttons (Centaurea cyanus), so called because they were a favorite for bachelor’s lapels. Flowers have long been used as a code for lovers. The bachelor button is said to be able to predict the future of a new relationship. Put a single flowerhead in your pocket and if the bachelor button is still alive the next day, you and your lover will have a long future together.

While bachelor buttons come in shades of blue most commonly, there are also dark, nearly black varieties that are stunning in the field or vase. Black Ball Bachelor’s Button has deep crimson-black flowers atop two- to three-foot-tall plants. These very dark maroon flowers bloom from June through August, smothering the plants with two-inch double flowers. These relatively tall flowers are quite effective when used in wildflower mixes. Planted in masses, they are absolutely striking. They mix especially well with cosmos (Cosmos bipinnatus). They are a real show-stopper planted among red poppies and snapdragons. You can also sow some among your day lilies for the back of the flower bed.

Because Black Ball Bachelor Buttons are easy to grow from seeds, they make a great plant for a child’s first garden. Planting these easy-to-grow flowers will give children a sense of accomplishment, and help build their confidence. You can even weave wreaths of them to hang around your child’s neck. Sow the seeds in early spring, planting the small seeds one-quarter-inch deep and one inch apart. Because bachelor button seeds need complete darkness to germinate, make sure they are well covered with soil, but not buried too deeply. For large plantings, scatter the seeds over the prepared bed, and then rake soil over them. When the seedlings are one to two inches tall, thin them out so they stand six to eight inches apart. Your first blossoms will appear just 10 to 12 weeks after planting.

Not only do Black Ball Bachelor Buttons look good in the garden, they make for an excellent cut flower whose blooms stay fresh for up to a week in a bouquet. You can even eat these flowers. The new, young shoots can be lightly steamed or added raw to salads. The colorful flowers make an unusual edible garnish.

Even though bachelor buttons are annuals, they often reseed themselves freely, and seem to come back for years. Like most flowers you can keep the blooms coming all season if you cut off the dead flowers, a process called deadheading. Even if you cut back dead flowers, let a few plants go to seed, not just to reseed next year’s blooms, but to provide fall and winter food for the birds. The thistle-like seeds will attract goldfinches.

To dry the flowers, pick them after the dew has dried, tie into bunches of six to 10 stalks, and hang bundles upside down in a dark, airy spot for several weeks.
Bachelor buttons grow well in containers, so try planting them in window boxes or individual pots. Plant them with alyssum, geraniums, lobelia, zinnias and dusty miller.

Plant dark Black Ball Bachelor Buttons for a casual landscape flower, to feed songbirds, or perhaps to put in a bachelor’s boutonniere. You may just predict the love of your life.

How to Grow Bachelor Buttons (Centaurea cyanus)

  1. Selecting your variety

Bachelor buttons come in many colors and mixes, the most common being the natural wild color of bright royal blue. We prefer growing the dark purple colored ‘Black Ball’ variety as well as the pure white ‘Snowman Ball’ variety for use in floral design, but there are also other mixtures of solids and marbled colors for a nice variety, such as Classic Magic and Classic Romance.

We are happy with our seeds from Geoseed, but Johnny’s Select Seeds, Floret and Swallowtail Seeds also carry a fine selection.

2. Scheduling

Bachelor buttons are a pretty quick flower, having just 65 days for growing from seed to bloom. You will want to plant them as early as possible, even when it is dipping below freezing at night just to allow them to establish a good system before it gets warm. Fall-sown or early spring/late winter sown bachelor buttons will have superior stem length and quality.

3. Seeding

Bachelor button seeds are easy given that they are so large and easy to handle. We plant ours into mini soil blocks, although you can also plant in 72 cell trays if you want large transplants. They should be up in a week or so when kept at 60-70 degrees, and they will grow very quickly so make sure to get them into high light as soon as possible – we tuck ours into a cold frame, but you can also grow them under lights. Try not to let them get leggy, although it isn’t impossible if they do get leggy.

If you’re good at direct sowing, you can put them directly into the field. We tend not to, since we’re growing on a smaller scale and have plenty of bird predation, but if you’re growing on a larger scale it may be easier and make more sense to direct sow.

4. Growing out

As I mentioned previously, bachelor buttons are like horses champing at the bit as far as their growth. If you’re not careful, they will grow up and out of the trays! I usually wait until they get their first set of true leaves, then immediately set them out to start hardening off to prevent them from getting leggy. This won’t take long, maybe a week or two before they’re ready for transplanting.

5. Planting out

Bachelor buttons transplants are also easy to handle (seeing a trend here?). We pop ours out into the field, burying them up to the level of the first set of true leaves. We tend to plant them in dense clumps, clustering several mini soil blocks around each irrigation emitter, as they will get nice and bushy after they’ve grown in. Make sure to water them in well and spray them with a bit of fish emulsion and kelp to give them a little boost of nutrients.

Make sure to pinch them as soon as you notice them having any vertical growth. If you don’t, you might end up with a giant central stem with a massive cluster of flowers. Which isn’t bad, but you’ll want to pinch low to get a lot of very productive side shoots, creating more of a spray effect of flowers.

6. Harvest

When you’re ready to harvest, you can choose one of two ways:

  1. Cut each stem individually

  2. Cut a “branch” of stems

Personally I prefer cutting a large branch of stems out – you just hunt down at the base for the stalk that the flowers you want are attached to, then chop the entire thing off. Much less combing through leaves and stems to find the one that you want, and if you’re doing a mass harvest for florists or events, it will make your harvesting much quicker and easier. Plus, if you need individual stems, you can just chop up the branch into the smaller pieces once it’s out of the plant and easier to handle.

Don’t worry regarding butchering this plant – it will grow back quickly and vigorously. It’s actually impressive just how fast the bachelor buttons will grow back to be honest, and continue to produce. Bachelor buttons are one of the longest flowering spring annuals as well, blooming for around ten weeks before petering out (although our first summer growing we actually harvested all the way through November!)

It’s important to keep bachelor buttons deadheaded – even if you’re not going to use them, make sure to keep the flowers harvested to prevent them from going to seed (which shuts down the flower production of the plant) as well as to ensure you don’t cut old flowers.

We usually end up ripping out our bachelor buttons in June to make room for other flowers, but if you have the space, bachelor button flowers are wonderful to use in floral crowns and garlands and as placeholder flowers later in the season, since they do pretty well out of water (just make sure to cut off the stems of course). They are also a great addition to floral confetti when dried.

Easy, productive, and simple – bachelor buttons are oftentimes overlooked as cut flowers, but they are a great staple to have for filling bouquets, arrangements as an accent flower, and are very useful as a dried flower as well. I will probably always grow them due to sentimental reasons, but I hope that this has kind of warmed you up to them!

Cornflower Seeds – Bachelor’s Button Wild Flower Seed

Flower Specifications

Approximate seeds per pound: 99,790

Season: Annual

USDA Zones: 3 – 10

Height: 24 inches

Bloom Season: Mid-summer and fall

Bloom Color: Blue

Environment: Full sun

Soil Type: Well-drained, pH 6.6 – 7.8

Deer Resistant: Yes

Planting Directions

Temperature: 60 – 70F

Average Germ Time: 7 – 14 days

Light Required: No

Depth: 1/4 inch

Sowing Rate: 4 ounces per 1,000 square feet or 10 pounds per acre

Moisture: Keep seeds moist until germination

Plant Spacing: 6 – 12 inches

Care & Maintenance: Cornflower

Cornflower (Centaurea Cyanus) – Well known and popular for being the truest blue flower, Cornflowers are a typical annual: they germinate easily from seeds, the plants grow quickly, and they bloom heavily. In the United State they are commonly called Bachelor’s Button and are found growing in the wild. Originally, Centaurea Cyanus came from Europe where they were found growing in corn and grain fields. Cornflowers make a great addition to the wild flower garden or flower border as they attract butterflies and beneficial insects. Even in natural settings, deer will often resist the these plants.

Cornflowers are known to be wonderful cut flowers. They perform well in the vase and also dry nicely to be used in everlasting arrangements. Bachelor’s Button flowers are not picky about soil types as long as it drains well. They prefer full sun and will withstand periods of drought. Most wild flowers will re-seed themselves; however, Cornflower does not do this in a consistent manner. To maintain successive seasons of a Cornflower meadow or similar natural display, it is recommended to sow seeds every spring.

Directly sow seed outdoors in early spring as soon as soil can be worked. Prepare seedbed by loosening soil and weeding. Broadcast seed and rake into the soil, covering the wild flower seed. Bachelor’s Button seed can also be sown in late fall, after several frosts. It will lay on the ground dormant until spring conditions bring on germination.

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