Cornflower seeds - Double Mixed - Seeds For Kids Ref: SUT140783 Features - A 'wacky' character to encourage children's interest in gardening, Flowering Time - Mid June-September Height - 90cm (36")., I'm Crazy. Choose a sunny site in the garden, with weed free soil. Put each seed into the soil, about 13mm (½") deep. Lightly cover with soil and water them well. Help them grow by feeding with plant food and watering them when they need it. You can also plant Cornflowers August-September to flower the next June-July. Price: £0.99 Quantity: