QuestionsHow to growFlowersSummer colour from seedFlowers for August 0 Vote Up Vote Down leone amon asked 15 years ago What flowers can I plant now that will flower and be 3 foot high by the last week of August? 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago If you can find cosmos or lavatera in the garden centres, these two will do the trick. Or you could go to the garden centre the week before and buy whatever they have in flower.