Start off in a seed tray indoors and plant out in borders. Fill a seed tray with good, free-draining, damp, seed compost. Sow seed on the surface of the compost and cover with a very fine sprinkling of dry vermiculite or finely sieved compost. Place the seed and tray in a propagator or seal inside a polythene bag and keep at around 20-25C (68-77F) until the seeds germinate. This will take about 7-21 days. Don’t exclude light as this helps germination.
When the seedlings are large enough to handle, transplant them individually into 7.5cm (3") pots or multi-cell trays. Before planting out, acclimatise the plants to cooler conditions by putting them outside for a few hours a day for a few weeks. Plant out when all risk of frost has gone about 30cm (12") apart.
Feed and water rudbeckia plants regularly. Deadhead faded rudbeckia flowers to encourage more blooms to be produced.