Rudbeckia
Rudbeckia fulgida
Rudbeckia (black-eyed Susan) is one of the most reliable late-summer and autumn-flowering perennials, producing masses of golden-yellow, daisy-like flowers with distinctive dark brown-black central cones from August well into October. They bring warm, sunset tones to borders at a time when many other plants are fading. R. fulgida var. sullivantii 'Goldsturm' is the gold standard — compact (60cm), incredibly floriferous, and tough as nails. It has an RHS AGM and performs reliably across the UK. R. fulgida var. deamii is slightly taller and equally tough. Annual rudbeckias (R. hirta varieties) are also brilliant — sow under cover in February for flowers from July. 'Cherokee Sunset' offers double flowers in bronze, russet, and mahogany; 'Cherry Brandy' is a striking deep red. Perennial rudbeckias prefer full sun in any reasonable soil — they tolerate clay, drought, and neglect once established. They spread steadily by underground rhizomes, forming impressive, long-lived clumps. Divide every 3–4 years in spring to maintain vigour. The dried seed heads look architectural in winter and provide food for birds. They're excellent cut flowers and combine superbly with ornamental grasses, asters, and salvias in prairie-style plantings.
Plan where to grow Rudbeckia using our vegetable garden planner.
When to Sow Rudbeckia
Sow rudbeckia in February, March, April.
Time to Harvest Rudbeckia
Expect to harvest approximately 5 months after sowing.
Companion Plants
Expected Yield
Ornamental — flowers August to October; outstanding for cut flowers and pollinator value.
Growing Tips
Incredibly tough and reliable; divide every 3–4 years
Common Problems with Rudbeckia
Powdery mildew in late summer
A white, powdery coating on lower leaves is common in late summer, especially in dry conditions with poor air circulation. It's largely cosmetic and doesn't usually affect flowering. Improve air circulation by spacing plants adequately, water at the base, and remove affected leaves. 'Goldsturm' has reasonable mildew resistance.
Slugs on young spring growth
Emerging shoots in spring can be eaten by slugs, especially in wet conditions. Apply organic slug pellets or nematode control in early spring. Once stems are established (15cm+), they're no longer vulnerable. Established clumps are very robust.
Plants becoming congested
After 3–4 years, clumps can become dense and flower less prolifically, with bare centres and vigorous outer edges. Lift and divide in early spring, replanting vigorous outer sections with fresh compost. Water well until re-established. This rejuvenates the planting and provides free new plants.
Plan your rudbeckia in the allotment planner
Drag and drop plants onto your plot and get personalised sowing reminders.
Open PlannerMore Flowers
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.