To grow Rudbeckia hirta, also known as Black-eyed Susan, from seed, you will need to follow a few steps. First, it is important to sow the seeds in early spring. This is typically around March or April, depending on your location and climate. By starting the seeds early, you give them plenty of time to establish and grow before the summer heat arrives.
Before sowing the seeds, prepare your soil by removing any weeds or debris and loosening it with a garden fork or tiller. Rudbeckias prefer well-draining soil, so adding compost or leaf mould to improve the soil structure and fertility is beneficial. This will provide the plants with the nutrients they need to thrive.
Next, scatter the seeds over the prepared soil, aiming for a spacing of about 12 to 18 inches apart. Gently press the seeds into the soil, ensuring they are in good contact with the ground. It is not necessary to cover the seeds with soil, as they need light to germinate.
To protect the seeds and seedlings from the elements and pests, it is advisable to cover them with a layer of horticultural fleece or a cloche. This will create a mini greenhouse effect and help maintain a more consistent temperature and moisture level. Keep the seeds and seedlings well-watered, but be careful not to overwater as this can lead to rotting.
Once the seedlings have grown to a size where they can be handled easily, usually around 2 to 3 inches tall, they can be potted on into individual pots. This will give them more space to grow and develop stronger root systems. Use a good quality potting mix and ensure the pots have drainage holes to prevent waterlogging.
At this stage, the seedlings can be placed in a greenhouse or on a sunny windowsill to continue their growth. They will benefit from plenty of light and warmth to encourage healthy growth. Be sure to water them regularly and keep an eye out for any signs of pests or diseases.
When the danger of frost has passed and the seedlings have grown to a size where they are sturdy and well-established, they can be hardened off. This involves gradually acclimatizing them to outdoor conditions by placing them outside during the day and bringing them in at night for a week or two. This helps them adjust to the temperature and environmental differences before being planted out permanently.
When planting out the Rudbeckia hirta seedlings, choose a sunny location with well-draining soil. Dig a generous planting hole, at least twice the size of the root ball, and incorporate compost or leaf mould to improve the soil fertility. Place the seedlings in the hole, ensuring they are at the same level as they were in the pots. Backfill the hole and firm the soil gently around the roots.
Water the newly planted seedlings thoroughly and continue to water regularly, especially during dry spells. Mulching around the plants with organic matter, such as straw or wood chips, will help conserve moisture and suppress weeds.
Rudbeckia hirta is a perennial plant, meaning it will come back year after year. Once established, it is fairly low maintenance and can tolerate periods of drought. However, it is a good idea to deadhead the spent flowers to encourage continuous blooming and prevent self-seeding. In colder climates, you may need to provide some winter protection, such as covering the plants with a layer of mulch or straw.
Growing Rudbeckia hirta from seed requires sowing in early spring, providing well-draining soil and adequate water, potting on the seedlings, hardening them off, and finally planting them out in a sunny location. With proper care and attention, you can enjoy the beautiful blooms of Rudbeckia hirta in your garden for years to come.
