Hardy Geranium (Cranesbill)
Geranium spp.
Hardy geraniums (not to be confused with pelargoniums, the tender 'geraniums' of windowboxes) are among the most useful, reliable, and low-maintenance perennials for UK gardens. They grow in sun or shade, tolerate poor or rich soil, and form weed-suppressing mounds of attractive, often semi-evergreen foliage topped with saucer-shaped flowers from May to October. 'Rozanne' is arguably the finest garden perennial of the last 30 years — it flowers non-stop from June to November with large blue-violet flowers, and was the RHS Plant of the Centenary. 'Johnson's Blue' is the classic border variety. For shade, G. macrorrhizum is unbeatable — aromatic foliage and tolerance of dry shade under trees. For ground cover, G. × cantabrigiense forms dense, weed-proof carpets. After the first flush of flowers, shear the whole plant back hard (the 'Chelsea chop') and it will produce fresh foliage and a second flush of blooms. Virtually pest and disease free.
Plan where to grow Hardy Geranium (Cranesbill) using our vegetable garden planner.
When to Sow Hardy Geranium (Cranesbill)
Sow hardy geranium (cranesbill) in March, April, May.
Time to Harvest Hardy Geranium (Cranesbill)
Expect to harvest approximately 12 months after sowing.
Expected Yield
Long-lived perennials that form expanding clumps; divide every 3–5 years.
Common Problems with Hardy Geranium (Cranesbill)
Vine weevil (container plants)
Notched leaves and root-eating grubs. Use nematode biological control in August–September.
Powdery mildew
Cut back after first flush (the 'Chelsea chop') for fresh, clean regrowth.
Seedlings reverting
Self-sown seedlings may differ from the parent. Remove if colour matters.
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French Marigold
Tagetes patula
French marigolds are the workhorses of companion planting — their pungent scent confuses pests and their roots release chemicals that suppress soil nematodes. They're particularly effective planted alongside tomatoes, peppers, and brassicas. Beyond pest control, they're genuinely beautiful, producing a non-stop display of orange, yellow, and red blooms from June until the first hard frost. They're among the easiest flowers to grow from seed, germinating quickly and flowering within 8 weeks of sowing. Deadhead regularly to keep the display going. In the allotment context, scatter them generously between vegetable rows — they attract hoverflies whose larvae devour aphids. The flowers are also edible, adding colour to salads.
Daffodil
Narcissus
Daffodils are the quintessential spring flower in Britain, carpeting woodland edges, roadside verges, and garden borders with golden yellow from February to April. They're incredibly easy to grow — plant bulbs in autumn, pointed end up, and they'll flower reliably for years with almost no care. They naturalise brilliantly in grass, creating meadow-like drifts that improve year on year. The key rule is never to cut back the foliage after flowering until it has yellowed naturally (at least six weeks) — the leaves are photosynthesising to recharge the bulb for next year's flowers. 'King Alfred' types give large trumpet flowers; 'Tête-à-Tête' is a compact miniature perfect for pots and borders. Daffodils are toxic to rodents and deer, so they're left alone where other bulbs get dug up. They're also poisonous to cats and dogs, so take care in gardens with pets.
Sunflower
Helianthus annuus
Sunflowers are the flowers that children grow and adults never tire of — their cheerful, towering presence lifts any garden. Giant varieties like 'Russian Giant' can reach 3 metres or more, turning any allotment into a dramatic backdrop. For cut flowers, try multi-headed varieties like 'Velvet Queen' (deep burgundy) or 'Lemon Queen' (pale yellow). Sow seeds directly where they're to grow from late April — they germinate quickly and grow at an astonishing rate. In exposed positions, stake tall varieties to prevent wind damage. The seed heads provide valuable food for goldfinches and other birds in autumn — leave them standing rather than cutting them down. Sunflowers also have practical uses on the allotment: they can act as living supports for climbing beans, their deep roots improve soil structure, and they attract pollinators to your plot. Slugs can destroy seedlings, so protect them until they're large enough to withstand nibbling.
Sweet Pea
Lathyrus odoratus
Sweet peas are the quintessential English cottage garden flower, grown primarily for their intoxicating scent and delicate, ruffled blooms. They're climbers, reaching 1.5–2 metres, and need support — wigwams of canes, trellis, or netting all work well. The golden rule is to pick, pick, pick: the more you cut, the more flowers the plant produces. Once you let seed pods develop, flowering slows dramatically. For the longest season, sow seeds in October in root trainers and overwinter in a cold frame — these autumn-sown plants flower weeks earlier than spring sowings. Alternatively, sow in March–April under cover. Nick or soak the seeds overnight before sowing to speed up germination of their hard seed coats. 'Matucana' has arguably the strongest scent; 'Spencer' types offer the largest, most ruffled blooms. Sweet peas make sublime cut flowers, filling a room with fragrance for days.