Black-eyed Susans (Rudbeckia hirta) are perennial wildflowers native to North America. These yellow and black daisy-like flowers thrive in full sun, growing 2 to 3 feet tall and blooming from July to September. Black-eyed Susans are hardy flowers that require little care and maintenance. They will tolerate poor soil with little water but if given a bit of care, will bloom more prolifically for a longer period.
Black-eyed Susans can be grown from seed or by purchasing mature plants. If starting from seed, wait until the spring when the ground is thawed and workable and sow directly into the garden. Work the soil and loosen it up before scattering your seeds. If seeds are started in early spring, you may have flowers that first year. If started later on during the summer or in early fall, flowers will not bloom until the following year.
If planting mature rudbeckia plants, select specimens with ample buds. After tilling the soil to loosen it, dig a hole twice the size of the plant’s rootball. Backfill the hole with soil and compost and water thoroughly. Mature plants should be spaced a bit over 1 feet apart as black-eyed Susans tend to spread quickly and they can be invasive to other plants.
Whether starting from seed or using mature plants, keep the soil moist after planting to encourage growth. Also select a location that receives full sun. Light shade will be tolerated, but black-eyed Susans thrive in full-sun locations.
Black-eyed Susans are incredibly hardy low-maintenance plants. They can tolerate poor soil and dry conditions once established and are generally disease-resistant. With a little bit of care, though, they will grow and bloom even better.
To fertilize, in the spring apply a thin layer of compost along with a 2-inch layer of mulch to retain moisture and control weeds. Water weekly if rainfall is less than an inch per week. This is especially necessary during the plant’s first year when it will need supplemental water. Try not to wet the foliage on the rudbeckia when watering as this can lead to black spots on the leaves. Watering early in the day so foliage has a chance to dry off before nightfall can usually curtail this problem.
As your black-eyed Susan blooms, deadheading will keep the flowers coming and extend the blooming season. Just snip off dead flowers weekly to keep the plant blooming into the fall. Toward the end of the blooming season, stop deadheading and leave some seed heads intact for birds to feed on.
Black-eyed Susans are vigorous growers that can often be invansive to other plants. If you start to run out of growing room, divide your rudbeckia every three to four. The best time to do this is in the spring when new growth begins. All you have to do is lift the plants from the ground and divide them into clumps.