Post category: Summer Colour





Pink candytuft and orange calendula with white campanula




Their main use, nowadays, is as colourful fillers-in, ideal for odd corners and gaps between other plants. They give a ‘cottage-garden’ look to a bed or border – a jumble of types of different heights and colours flowering over a period in mid-summer.


Plant raising


Hardy annuals are raised from seed sown in seed trays or directly in the ground where the plants are to flower. They can be sown in March, April or May. March sowings can be affected by cold, wet weather. May sowings can be affected by dry conditions and, anyway, they tend to flower late. Early April is usually a good time.

Seeds of some types can be sown in September, too. These over-winter as young plants and flower earlier the following summer than the spring sowings.

Dig the ground, working in general fertiliser at 70 grams per square metre. Break up all lumps and rake the surface fine. Some peat or organic material might be worked in too if the soil is poor. Make little drills with a stick about 15 centimetres apart and 1 centimetre deep. Sow the seed thinly and cover with soil.

If the area being sown is larger than about 1 square metre divide the space into areas of about this size and sow a few different types. Seed can be sown broadly scattered about too, but sowing in lines makes it easier to distinguish flower seedlings from weeds.

Hardy annuals grow best in good, fertile, but not over-rich soil in full sunshine. Some kinds, such as California poppy and pot marigold, can tolerate poor, dry soil.



Californian poppy

Californian poppy



Aftercare for hardy annuals


When the rows of seedlings can be distinguished, lightly run a hoe between them to kill weed seedlings. Weeds should never be allowed to get established. Watch for slugs and snails, too. When the seedlings are about 2 centimetres high, a first thinning can be carried out, though, if the seeds were sown thinly enough, this will not be necessary.

When the seedlings are 5 centimetres high, they can be thinned to their final spacing. This varies from 5 to 10 centimetres apart for small kinds to 30 centimetres apart for large types. If there are gaps, they can be filled by lifting and transplanting excess seedlings carefully.

Some of the taller types may flop about when grown on good soil. Bushy twigs might be used for support. Hardy annuals often self-seed, so areas of the garden might be set aside for this to occur.