I was surprised to see two pots of impatiens along the walkway at school. This shade-loving plant has been in the news a lot lately. Here is an excerpt from the Washington Post:
"Impatiens are cheerful, mounded annuals that provide precious and steady floral display in shadier corners of the patio and border and look great in containers. But they are so good, folks with sun-robbed yards don’t think to plant much else. This year, they might have to.
A widespread and devastating disease, impatiens downy mildew, escaped the controlled environment of the growers’ greenhouse two years ago and has spread virulently in the gardens and commercial and institutional landscapes in 35 states.
The official advice is that if your impatiens melted and died abruptly last year, skip them for this growing season. Even if they didn’t, planting them will be a big risk as humid and moist conditions "
The article goes on to say, "The disease affects common garden impatiens, hybrids of a species called Impatiens walleriana. The more sun-tolerant New Guinea impatiens are bred from a different species and are tolerant to the disease.
In the early stages, the leaves begin to curl and develop a yellow cast. This often leads to a white fuzz on the underside of leaves — hence “downy” — followed by leaf and flower drop and, finally, a collapse of the fleshy stems.
The spores of the fungus can survive [the winter] in the soil and can survive on some weed hosts,” said Adria Bordas, horticultural extension agent for Fairfax County. She advised against planting impatiens where you grew them last year, especially if they succumbed to the downy mildew.
The spores travel in the air for miles and spread between plants in water on leaves, from rain or irrigation systems.
The diseased plants on one property, unless they are pulled and bagged right away, are likely to infect neighboring impatients."
Since these plants were selected by professional landscapers, I'm hoping they were grown from unblemished stock. Since Richmond's summers are usually humid, we will soon learn if they will survive the fungus.
