5 Plants that flower all summer Hardy Geraniums not the annual version They have Pollinator-friendly blooms throughout summer and into autumn and many will grow happily in partial shade or sun Erigeron or campanula Ideal for planting in the crevices of walls, steps and paving stones. Sweet peas These popular annuals can begin flowering as early as May. For colour all summer long Penstemon If you’re looking for instant colour, penstemons are the answer. Plant in groups of three or five for impact