With any mild weather, it would be tempting to go and buy some annual plugs. This can be achieved by sowing seeds though. Some are more hardy than others as the descriptions illustrate, some annuals can be classed as perennials since they come back a following year. If the parent plant doesn’t, it can throw its seed and the cycle repeats itself. The half hardy / hardy is an indication of what conditions it can withstand and whether this is for a prolonged period or a cold snap.
Calendula officianalis ‘pink surprise’- marigolds offer flowers from summer to autumn in warmer climes. Their demise is slug / snail related, not so much weather. Marigolds do best in full sun with well drained soil. They can self seed to prolong their lifespan. If you don’t want them, you need to pull them out once the flowers are spent.
Papaver orientale – Poppies can be sown for spring and if provided with good drainage, a full sun aspect will return the following year. Equally, Eschscholzia californica, an annual though, under the right conditions can be treated as a perennial. It may self seed so be mindful if you don’t want it populating.
Viola – Wild violets are prolific in meadow areas and woodlands alike. These will return season after season. They’ll self seed and appear almost anywhere. The cultivated variety is an annual and normally dies after its season. It doesn’t self seed. They’re closely related to the pansy.
Pansies – There are summer and winter varieties. Single coloured and tricolour. Often described as a “cool weather annual” they can often survive prolonged cold snaps and on occasions come back when they’re not meant to.
Dianthus or pinks are a carnation flower suitable in rock gardens / herbaceous borders. The cut flowers, we associate with a florists spray (carnations) but the smaller ones are perennials. The plant is low growing with mat forming foliage. It offers fragrant flowers in the summer. Pinks can cope in poor soil.
Salvia horminum – clary sage / annual sage needs full sun or light shade but offers a show from summer through to autumn. The flowers attract beneficial insects so a bio diverse choice. it needs a decent, humus rich medium and does not sit well in poor soil.
Polyanthus / Primula – although these are removed to make way for summer bedding, this perennial survives cold snaps and returns the following year. It is argued that they come back stronger and flower in profusion.
Nasturtiums – an annual / perennial in the right conditions. The perennial variety – Tropaeolum – is hardy. The annuals, however, need to be sown early spring. if you are buying them as plugs slightly later.
Nigella damascena “Miss Jekyll” – Love-in-a-mist offers a blue accent in summer. The annual suited to a sunny spot will do well if a little sheltered.