Garden Detective: Transplanting rhododendron
Rhododendron shrubs transplant fairly easily due to shallow root systems. Credit: AP
The new location should offer some shade, and the soil there should be on the acidic side, with a pH level around 5.5. To keep root exposure to a minimum, plant quickly into a hole that you've prepared in advance. Mix equal parts compost or well-rotted manure with the soil removed from the hole and fill halfway. Tamp down firmly to eliminate air pockets and water before filling the remainder of the hole. Tamp again and water well. Mulch with an acidic variety like shredded oak leaves or pine needles.
Monitor soil moisture all season and water regularly until frost, as you would a new plant. Once re-established, rhododendrons typically don't require much attention.
Every year since then, the pathogen has been present and weather conditions favorable for a re-emergence. Now, for the fourth consecutive year, it's back: Late blight was identified earlier this month on a farm in the Riverhead area.
The disease is caused by a pathogen that can release millions of spores per plant per day, especially during wet weather. Those spores are carried by wind "typically within 30 miles but potentially long distances until air currents or rain bring them back down," said Meg McGrath, a Cornell University plant pathologist stationed at the Riverhead office of the Cornell Cooperative Extension of Suffolk County. Theoretically, spores from one infected plant in Nassau County could destroy an entire crop on a farm in Riverhead, she added.
The disease results in elongated brown lesions on stems and large grayish-green to brown spots on leaves that cause the plant to blacken, wilt and die. White mold full of spores encircles spots visible on the undersides of leaves.
Start inspecting potato and tomato plants now, and continue to do so every week throughout the growing season. "Keeping an eye out for symptoms, reporting and managing late blight are the responsibility of anyone growing these crops," said McGrath.
If late blight is detected, plants should immediately be bagged tightly in plastic and set in the sun for a few days until they die, then disposed of only in the trash -- never composted or left on the ground in piles, as spores will continue to form until the plant dries up.
