Black-eyed Susans Soak In Sun
by Shelly Nold
WHEN WE RETREAT into the comfort of our air-conditioned homes to escape the heat of late summer, what better way to bring the garden inside than with beautiful fresh-cut flowers? Rudbeckia hirta ‘Prairie Sun’ and ‘Denver Daisy’ are just a few of the beautiful half-hardy black-eyed Susans commonly available.
BLACK-EYED SUSANS ARE GROWN primarily for their large daisy-like flowers, which can be 4 to 6 inches in diameter. Prairie Sun has solid yellow petals with green disc flowers, and Denver Daisy has yellow petals with a splash of red/brown at the base of the petal and chocolate brown disc flowers.
THEY BLOOM FROM LATE JUNE until frost and benefit from regular deadheading. Later in the season, you can stop deadheading and let the flowers go to seed, a favored food source for many songbirds.
THE PLANTS’ GRASSY GREEN LEAVES, as well as the stems, are covered with stiff hairs or bristles. Black-eyed Susans tend to perform best in dry summers because the hairy foliage can hold water and encourage fungal leaf diseases like powdery mildew, which reduces vigor and destroys the foliage.
BOTH VARIETIES CAN GROW 2.5 to 3 feet tall and typically 1 to 1.5 feet in diameter. They can be planted singly or in small or large groups. They prefer full sun and tolerate a wide range of soils, but they do not perform well where the soil is wet. They are quite drought-tolerant once established. They add bright color to the summer and fall garden.
Shelly Nold is a horticulturist and owner of The Plant Kingdom. Send stories and ideas to her at The Plant Kingdom, 4101 Westport Road, Louisville, KY 40207.
ASK THE GARDENER
by: Angie McManus
I planted a rose bush about three years ago. It had blooms the first year, but none since. Why is it not blooming?
When roses do not bloom, it is usually due to lack of sufficient sunlight or inadequate nutrient levels. You mentioned that your shrub flowered the first year but has not in the past couple. Is it planted where it gets a minimum of six hours of direct sunlight? Is it receiving less light than in the past for any reason? If it is not getting adequate light, it will not bloom.
The same goes for nutrient levels: either too little or too much can cause plants not to bloom. This is why following recommended application rates is so important. These are the two main reasons roses stop blooming, but they also have their share of insect and disease problems.
Does the overall health of the plant look good? If not, you should take a sample to your County Extension Service to have the horticulture agent take a look or to a local garden center or nursery that has a knowledgeable staff. You can have your soil tested through the Extension office for a small fee. The results will tell you if you need to add anything to the soil.
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