Annuals are the fast-living members of the flowering plant world. Their entire life cycle, from seed germination to seed production, can be completed in just a few months. They have one purpose, there’s one reason for the flowers they produce, to make seed and ensure there will be a next generation. Annuals can bring almost instant colour to a garden, many make brilliant cut flowers, and some of them produce bucket-loads of pollen and nectar for bees. All told, these plants make a very desirable and easy going addition to any garden.
Seed catalogues usually list annuals as either hardy or half-hardy. The difference comes in the time they can be sown and planted out. Hardy annuals are, as the name suggests, more tolerant of colder conditions. They can be sown direct as the soil begins to warm in the spring, or started in pots with a little protection to get a head start on the growing season. Not too soon though, generally around April or May, when there will be enough light for rapid but sturdy growth. Half hardies are that bit more delicate and won’t survive a frost. They are best started indoors and given a few weeks of protected growing to ensure they are ready to plant out once the cold nights have passed.
If you’re keen to have a go at growing flowers, but aren’t quite sure where to start, hardy annuals can be a quick and easy introduction. There’s no specialist equipment required, just a packet or two of seeds, and a patch of decent soil that gets plenty of sun.
How to grow hardy annuals
Find a patch of well-drained soil, preferably in full sun. It can be a space dedicated to growing annuals, or a bare spot in the perennial border. Most hardy annuals don’t need especially rich soil, in fact too much fertiliser can result in big, leafy plants with fewer flowers. Sweet peas are an exception to this rule, they love a good, rich soil, But we can deal with sweet peas another time. Remove any weeds, then rake over the soil to get a fairly fine texture. If the soil is very dry, give it a good but gentle watering before adding the seeds – a watering can with a rose is really useful for this.
Depending on how much space you have, you might want to grow just one type of flower or go for an artfully designed mixture. Even in a small space, there can be room for a vibrant and diverse display. Scatter your chosen seeds evenly and thinly across the surface of the soil. Alternatively, create shallow indentations in lines and sow into these. The advantage of sowing in straight lines is that it is easier to identify and remove weed seedlings as the young plants develop. Gently cover the seeds with a little soil. If there are cats or birds in the neighbourhood that are likely to scratch up your carefully sown patch, protect the soil surface with some netting or thorny twigs.
Now you can stand back and wait for green shoots to appear. If the weather is dry, water the patch to keep the soil damp, but not soggy. Chances are, as your new seedlings emerge the weeds will too. With a little experience, you’ll soon learn which plants to keep and which to pull up – if you’re really not sure, Twitter is a great source of guidance from gardeners who are more than happy to help.
Once the plants start to develop, take a look at the space and decide if you need to take some of them out and give the remaining plants more room to grow. These ‘thinnings’ can either be composted or, if you can carefully dig them up without too much disturbance, transplanted to another area of the garden (or a friend’s garden…)
With a little bit of care, your annuals should give you a colourful display through the summer. To keep the colour coming for as long as possible, cut or pinch off the flowers as they are past their best. Remember that the plant’s purpose in life is to produce seed. By removing the flowers before they get to that stage, you are encouraging the production of more flowers.
Five hardy annuals to get started with
Cornflower (Centaurea cyanus) – very easy to grow, producing beautiful blue flowers, which look good in a border and make long lasting cut flowers too. Cornflowers are a bit floppy, give them some support to grow through using sticks and garden twine.
Borage (Borago officinalis) – a stocky annual, borage is brilliant for bees. The flowers can be frozen into ice cubes – perfect for adding glamour to a glass of Pimms!
Pot marigold (Calendula officinalis) – another incredibly easy to grow plant. The bright orange flowers of calendula attract hoverflies and add a vivid splash of colour to the summer garden.
Nasturtium (Tropaeolum majus) – both the leaves and flowers of nasturtium can be added to summer salads for a peppery contrast to milder lettuce leaves.
Poppy – scatter seeds of the common poppy (Papaver rhoeas) and opium poppy (Papaver somniferum) over freshly dug soil and they will grow away quite happily. If you allow seed heads to form, they can be cut and added to flower arrangements. The seeds can also be collected and used for cakes and breads.