How to Grow Cornflowers (WildFlower) : A Practical Guide from Seed to Flowers

Cornflowers are one of the easiest wildflowers to grow from seed and a great choice if you want to bring more bees and other pollinating insects into the garden.

The familiar wild cornflower has beautiful blue flowers, although cultivated varieties can come in other colours too. For our wildlife planting, it's the traditional blue cornflower that really gives you that classic cornfield look.

They're annuals, so unlike oxeye daisies they won't come back from the same plant year after year. The good news is that they're very easy to sow and will often self-seed if you leave some flower heads to mature.

Cornflowers don't need rich soil or lots of feeding. Give them a sunny position, reasonably well-drained ground and don't fuss over them too much.

They're ideal for wildflower areas and informal borders, and you can grow them in pots too. They're also good for cutting, although I always leave plenty of flowers for the insects to pollinate.

When to Sow

Cornflowers can be sown in spring or autumn.

For spring sowing, sow from March to May.  I always sow these wild flowers they're directly where I want them to flower want them to grow

You can also sow from August to October for flowers the following year. Autumn-sown plants establish before winter and can often make stronger plants and flower earlier than spring sowings.

If you have enough seed and space, there's nothing wrong with doing both. An autumn sowing followed by another small sowing in spring can help extend the display.

Don't worry if autumn seedlings remain fairly small over winter. They'll get moving again once conditions improve in spring.

How to Sow

Cornflowers are straightforward to sow directly outside.

Choose a sunny area and remove weeds before you start. Rake the soil to create a reasonably fine surface, but there's no need to turn a wildflower patch into something resembling a seed tray.

Make shallow drills around 1cm deep and sow the seeds thinly.

Cover lightly with soil, gently firm the surface and water if the ground is dry.

I want to create a natural-looking display, you I dont sow everything in straight lines but Scatter small groups through the area and lightly rake them into the surface.

The important thing is good contact between the seed and soil without burying it too deeply.

Thinning and Growing On

Once your seedlings appear, thin them if they're badly overcrowded. This is the step I often forget but if you aim for roughly 15–20cm between plants. They can grow closer together in a natural wildflower display, but giving them a little room usually produces stronger plants with more branching.

Keep weeds under control while the cornflowers are young.

This matters more than feeding them. A young wildflower seedling struggling amongst vigorous weeds has a much harder time than one growing in fairly poor but open soil.

Once cornflowers get established, they grow quickly and need very little attention.

Taller plants may lean into their neighbours, particularly in a wildflower area. I don't worry about that as part of a wildflower display is the wild look.

Growing in Pots

Cornflowers can be grown successfully in containers if you don't have space for a wildflower patch.

Choose a reasonably deep pot with drainage holes and place it somewhere sunny.

You can sow directly into the container rather than transplanting seedlings later. Thin them as they grow so they aren't badly overcrowded.

Container-grown cornflowers will need more regular watering than plants growing in the ground, particularly during warm weather.

There's usually no need for lots of feeding. Too much fertiliser can encourage soft, leafy growth rather than the sturdy flowering plants you're after.

Cornflowers look particularly good in larger containers where you can grow several plants together.

And if you're gardening on a patio or balcony, even a pot of flowers gives visiting insects somewhere else to stop and feed.

Watering and Feeding

Cornflowers are fairly tolerant once established.

Keep young plants watered while they're developing, particularly during dry spring weather. Once their roots are established, plants growing in the ground generally only need additional water during prolonged dry spells.

They generally dont need watering.

Containers need checking more frequently because compost dries much faster than garden soil.

Feeding usually isn't necessary in the ground. Cornflowers naturally grow well in relatively low-fertility conditions and don't need the treatment you'd give hungry vegetables.

If you're growing them in containers for a long season, an occasional light feed won't hurt, but don't overdo it.

If you've got huge green cornflowers with disappointingly few flowers, very rich soil or too much feeding may be part of the problem.

For a wildflower, slightly leaner conditions are often exactly what you want.

Flowering and Deadheading

Cornflowers usually flower from early to late summer, depending on when they were sown and the conditions in your garden.

The flowers are excellent for pollinating insects, particularly bees.

If you're growing them in an ornamental border, regular deadheading can encourage the plants to keep producing flowers for longer.

For a wildlife area, I wouldn't deadhead everything.

Remove some fading flowers if you want to prolong the display, but leave others to develop seed. That gives the plants a chance to self-seed and provide another generation for next year.

Cornflowers also make lovely cut flowers. Pick stems when the flowers are fresh and continue cutting regularly if you're growing a patch specifically for the vase.

Saving Seed and Self-Seeding

If you'd like cornflowers to appear again next year, leave some flower heads on the plants after flowering.

The seed heads will gradually dry and mature.

You can either allow them to drop their seed naturally or collect some yourself. Wait until the heads are dry, then remove the seeds and store them somewhere cool and dry for sowing later.

Self-seeding can give you a wonderfully natural display, although the seedlings won't necessarily appear exactly where you planned them.

I don't mind that in a wildflower patch. If they appear somewhere completely unsuitable, they're easy enough to remove while young.

At the end of the season, don't be too quick to clear everything away before the seeds have had time to mature.

A slightly untidy patch for a few weeks can save you some sowing next year.

Why Cornflowers Are Good for Wildlife

Cornflowers are particularly useful for bees and other pollinating insects, which visit the flowers for nectar and pollen.

Their open flower heads make them easy for insects to access, and a group of plants can provide plenty of flowers through the summer.

They're especially useful as part of a mixture of flowers rather than being the only wildlife plant in the garden. Different flower shapes and flowering periods provide food for a wider range of insects over a longer season.

That's something I'd encourage throughout the wildlife garden.

Grow several different things and try to have something flowering for as much of the season as possible.

Cornflowers are a very easy place to start.

Common Problems

Slugs and Snails

Young cornflower seedlings can be damaged by slugs and snails, particularly during damp weather.

Keep an eye on them while they're small. Once plants are established and growing strongly, a little damage usually isn't much of a problem.

Seedlings Not Appearing

Cold, waterlogged soil can slow germination, while very dry soil can cause newly germinating seeds to struggle.

Prepare the ground reasonably well and keep spring sowings watered if the weather turns dry.

Plants Becoming Tall and Floppy

Cornflowers can become fairly tall, particularly in rich soil or sheltered conditions.

In a natural wildflower area, I generally let them lean into neighbouring plants. If you're growing them in a more formal border, discreet support can help.

Lots of Leaves but Few Flowers

Very rich soil or too much fertiliser can encourage leafy growth.

Don't feed cornflowers heavily and give them plenty of sunshine.

Aphids

Aphids can occasionally gather around tender shoots and flower stems.

Small infestations can often be left for natural predators or washed away if necessary. In a wildlife garden, I'd give ladybirds, hoverfly larvae and other beneficial insects a chance to find them before getting too involved.

Powdery Mildew

A powdery coating can occasionally develop on foliage, particularly later in the season.

Give plants enough space for reasonable airflow and water during prolonged dry weather. A little mildew on plants that have already given you months of flowers isn't something I'd worry about too much.

Cornflowers are exactly the sort of wildflower I'd recommend if you're just starting to grow for wildlife. Sow them directly, give them sunshine and leave some flowers to set seed. You'll get a lovely summer display without much work, and you'll probably find the bees notice them long before you do.