Seeds are solution to add colour

Cosmos should last until November. Picture by Tom Pattinson.
Cosmos should last until November. Picture by Tom Pattinson.

Time is up under cover for all the summer bedding plants, those raised from seed in-house and others bought-in as plug plants.

They’ve developed well in the cold greenhouse. Some have already been introduced to cooler nights outside as a toughening-up exercise.

Spring container displays have run out of steam and the change-over has arrived.

Last week all polyanthus plants were removed, some divided up and transplanted into rows on a spare piece of land that will be their home until the autumn. With occasional watering, they’ll remain healthy for replanting in October.

Half-hardy annuals introduced to hanging baskets then immediately fixed outdoors are at the mercy of our weather during May/June so the best approach is to complete their planting, then allow a period of development under cover – a polytunnel or greenhouse is ideal.

If you find the price of a tray of summer bedding too high, consider an alternative. A packet of hardy annual flower seed costs less than £2.50 and has the potential to fill one square metre.

We sow such patches in the mixed borders.

The shape can be irregular, but rather than broadcast the seed, create short drills, 15cm apart, with the back of a rake. When seeds germinate in rows you can distinguish between them and weeds.

Hardy annuals could be a simple solution for a piece of land in need of brightening up. Clear the area of stones or debris, fork and rake over, and mark out the sowing bays with sand.

Consider the colour and height of plants in deciding their position. Sow now and anticipate the first to appear in 14 days. They should all be in bloom for July and continue until September.

I noted 10 varieties capable of such a task in a seed display at the local garden centre last week. Agrostemma, godetia, lavatera, larkspur, cornflower, calendula, cosmos, nasturtium, eschscholzia and annual chrysanthemum would do the job, but the choice is yours.