border England english flowers garden Great Britain lavatera nature perennial petals pink plant ribbed shrub summer herbaceous mauve red stems a lot of flowers bloom blooming blooms flower flowering gardening green iris irises park plants spring yellow bush coast edible Eleagnaceae fruit Hippophae rhamnoides natural norfolk orange sea buckthorn shore wild woody plant Aconitum blue cultivar grow monkshood Ranunculaceae spikes tall autumn dahlias heads magenta perennials purple pale annual Asteraceae companion planting flora florets garden flowers garden marigolds garden plants herbaceous plants historical horticulture pungent ruffled petals sunflower family symbolic symbolism Tagetes bulb color colorful colour colourful floral garden flower garden plant horticultural leaves stalks tulip Dog's mercury Euphorbiaceae Mercurialis perennis poisonous uk united kingdom