10 Hardy Annual Flowers to Grow from Seed

10 Hardy Annual Flowers is written to help you have a ‘quick fix’ garden filled with flowers this summer. Annual flowers are a great way to –

let those who are renting properties to add an individual touch to the garden
fill in gaps between existing, mature shrubs without being permanent, as they do not require much root depth
provide food – nectar – for pollinating insects such as bees and butterflies
give you a pretty ‘stop gap’ measure when you’re not sure what to do with a particular area in your garden
give you a flower filled garden right from the beginning – as in a newly planted design, there will be spaces left for the perennial plants to grow – annuals fill up those gaps
help reduce weeds by covering up bare earth – easier maintenance gardening
provide cut flowers for the house
fill a newly moved into garden with colour when you’re not sure what the previous owners may have planted

But what does “hardy annual flower” mean?

The common definition of an annual is a plant which is sown from seed, grows, flowers and sets seed within the space of a season.

Annual flowers can be divided in to hardy annuals and half-hardy annuals. There are other sub divisions, but we’ll keep it simple for now. For more info, check out the blog link on Annuals below.
Half-hardy annual flowers need to be started off as seed sown under protection, for example in a heated greenhouse. Or they need to be sown later in the year when the risk of frost has gone.

But I wanted to suggest flowers that you can sow the seed for and then sit back and wait for them to grow… Well, it’s more or less that easy!

And so we have 10 hardy annual flowers that are good to grow from seed. We’ll look at the flowers first, and then I’ve given you some tips. There are blog links for some of the flowers, plus sowing and growing tips at the end.

Our list of 10 Flowers

These are 10 hardy annual flowers which I have grown in my own garden, and have used in planting designs for clients. They are all pollinator friendly and two are heavily scented for human delight. Some will act as companion plants for your veggies. Between them, you should have annual flower heaven from May to October! Alphabetical list first and then each one described in case they’re not familiar to you.

Alyssum, Lobularia maritima
Cornflower, Centaurea cyanus
Love in a mist, Nigella damascena
Marigold, Calendula
Nasturtium, Tropaeolum majus
Night scented stock, Matthiola longipetala
Poached egg plant, Limnanthes douglasii
Poppy, Papaver
Sunflower, Helianthus annuus
Sweet peas, Lathyrus annus

10 Hardy Annual Flowers

Alyssum

Alyssum maritimum, also known as Lobularia maritima and sweet alison, is occasionally a short lived perennial rather than an annual. A low growing, scented white carpet of flowers suitable for coastal gardens, Alyssum is useful for rock gardens, troughs and raised beds over recycling boxes. Growing this cascade nearer nose level does allow you to discover the delicate scent of this tough annual flower. There are also purple and pink varieties, a familiar sight in many seaside gardens, but did you know it is related to cabbages?

Cornflower

The annual cornflower, Centaurea cyanus, also commonly known as bachelor’s button is a blue flower frequently found in wildflower mixes. It is a native species across much of Europe and is much loved by bees and other pollinating insects. It used to be a common site in cornfields, which is where the common name originated. Cornflower can also be found in pink and white variants, usually in a mixed pack of cornflower seed.

Love in a Mist

Nigella damascena, or Love in a mist, has pretty blue flowers and decorative seed heads, with delicate foliage. This gives them a longer season of interest than just flowering. The blue flowers may be a mid-blue or even turquoise. White flowered and double flowered varieties are available, for example, Nigella damascena ‘Miss Jekyll alba’. Nigella seeds may be used in baking.

Marigold Calendula

The common name for Calendula is marigold or pot marigold. Not to be confused with French marigold, which is Tagetes. Usually found as bright yellows and orange flowers, there are creamy tones to be found in varieties such as ‘art shades’. Calendula is frequently used in companion planting and as an edible flower in salads.

Nasturtium

Nasturtium, Tropaeolum majus, is another edible flower. These “mastershalums” of Winnie the Pooh fame are great for growing in poor ground. In fact, they’re best not grown in rich soil as they put on more foliage than flowers when they are. They will trail down from hanging baskets or meander along the ground.

Night scented stock

Matthiola longipetala may be a bit of a mouthful, but the sweet aroma in the evening is a welcome “noseful.” Like nasturtiums, night scented stock, or evening stock, flower more profusely in a poorer soil; they’re also tolerant of drought. Night scented plants are particularly enjoyable for those who mainly sit out in their gardens after a hard day’s work.

Poached egg plant

I wanted to include at least plant you may not be familiar with in our list of 10 hardy annual flowers and I feel this might be the one…
Limnanthes douglasii has the common name of “poached egg plant” or “fried egg plant” due to its yellow and white cup shaped flowers. Much loved by hover flies this is a low growing scented annual that will grow happily next to a path. It also makes a pretty edge to a raised vegetable border, doubling up as a companion plant.

Poppies

Whether you grow red field poppies, Papaver rhoeas, delicate Shirley poppies (see blog link), or black centred ladybird poppies, you couldn’t find an easier flower to scatter the seed for. Annual poppies self-seed easily. I remember one year I was particularly busy in spring and didn’t carry out my usual cull of poppy seedlings in the front garden. It was a sea of soft lilac flowers and blue-grey foliage for about 3 weeks – an absolute delight. Poppy seeds may be used in baking.

Sunflowers

Helianthus annuus – the botanical Latin tells us straight away that this sunflowers are an annual flower that loves the sun. It looks like child’s picture of the sun surrounded by its rays of light. I love the way sunflower heads track the sun as it moves across the sky. (see blog link for more on the sunflower) Slugs and snails do find young sunflowers tasty, so you may need a surrounding barrier of eggshells or coffee grounds.

Sweet peas

Sweet peas, Lathyrus annus, perform best if their roots are forced to grow in a deep, narrow channel. Sow the seeds in special pots or recycle – use tubes such as kitchen towel / loo roll inners or make a tall newspaper pot. This soil depth will give the Sweet pea roots a strong start. The homemade pots and cardboard tubes can be planted along with the sweet pea seedlings when they’re planted out into the ground.

Growing the 10 Hardy Annual Flowers from Seed

Most of the seeds will need protection if you’re sowing them earlier in the year, when there might still be frosts. But this protection can be a windowsill or a simple pop up patio “greenhouse”, a cold frame or unheated greenhouse. A cover for the seed tray and making sure its not placed directly onto the cold ground will be all the protection that’s needed. Oh yes, and some of that is to keep the flower seeds from being eaten by mice rather than getting too cold!

However, it is possible to sow and grow these flowers without the need for a heated green house or in some cases any special equipment at all.

All these flowers can be grown by directly sowing the seed into the open ground. If you’re new to gardening or not sure of your weeds, here are a couple of tips you may find helpful to prevent pulling up your flower seedlings by mistake: –

sow them as a circular shape, or zigzag, a smiley face
trickle some sand on the ground where you’ve sown the seeds

Germination is triggered by the correct combination of light levels, temperature and moisture. Some seeds, usually the smaller ones, will need only a light sprinkling of fine sand over them. Others will need seed or potting compost. This is true if whether you’re sowing the seed in a seed tray or directly into an open border.

Fun Gardening Lesson Tip

You may like to do this with children, for your own pleasure or because you’ve found an old pack of seeds and aren’t sure if its worthwhile sowing them. My grown-up students and I have fun doing this in Plews gardening courses!

place the seeds on moist kitchen roll and fold the towel over them
lay the kitchen roll in a sealed container or plastic bag and place it in a warm room
NB some seeds need a period of cold to germinates, if it says this on the packet, then pop them into the fridge not a warm room
they should swell and begin to sprout in a few days
you can then sow them into pots or the ground, taking care not to damage that tiny root that’s forming

For more details on sowing seeds indoor and outside, including a how to video, see the blog links below. For more of what we get up to in Plews Gardening Courses, have a read of this Lessons blog

And finally

There you have it, 10 Hardy Annual Flowers to grow from seed to look wonderful in your garden! I will revisit hardy annuals from a planting design and garden design perspective in another blog, and share some more tips and ideas with you. In the meantime, enjoy looking through the links below, and exploring more ideas from Plews Potting Shed.

If you would like help with gardening, a garden design or planting design do get in touch. Plews is able to offer you Gardening Lessons, Garden Design and Planting Designs or a Garden Consultancy Visit to suit your needs. Please check out relevant pages on the website for more details

For further gardening tips and inspiration check out Plews Potting Shed blogs, including the selection below – and find us on Instagram and Facebook