Nursery Notes by Mark Halcomb, Release May 16, 2007

Freeze Update

Update 5 weeks after the freeze that occurred April 6-9. Many of these entries are based on one account and possibly not witnessed by myself. I typed this May 14, 2007.

The wheat that was in the boot stage during the freeze died. Younger wheat survived. There might be some straw produced locally after all.

Recently emerged seedlings and first year buds were killed unless protected. I have received mixed reports on the survival of those protected; probably due to how well protected. Some peach seedlings survived on northern slopes because they were slower to warm and germinate.The same producer remarked that he planted slightly deeper than normal last fall.

Plants with busted bark: container Dwarf Burford that were under poly (Compacta, Blue Girl & Manhattan okay at same site); crapemyrtle, foster holly & Nellie R. Stevens holly in Alabama; Boxwoods younger than 2 years in Coffee & Warren Co; 2" Shumard oak on north side; Foster holly under 2'; 2" sawtooth oak busted at soil; splits in 2" Bost elm; 3 accounts of browning 5-6' Emerald Arborvitae reported 5-8-07 (1 nursery had found split bark; others probably had not checked); 3" Nuttal oak; 6 to 8" splits in trunks of Accolade Elm.

Village Green Zelkova, London Plane, ginkgo and Dura-Heat loss at another nursery, not previously reported. But, I do not know if bark busted. He said that he lost them. Another producer rattled off that his magnolia, locust, elm, ginkgo and Zelkova were killed.

Some Leylands browning. Brown areas (dead) on stems of 6' Cleveland pear liners. Various Prunus 5 to 6' whips and branched have a very dark brown color under the cambium. The ones I have seen will likely die during the summer. Not all Boxwoods are busted by any means. The American faired better than the rest. Some 6' Foster hollies have no foliage, while others only lost the newest spring growth. Maples and cherry generally look good.

I have seen irrigation running and others saying they needed to. We did get a rain Friday, a half inch for me and 2 inches in town. Moisture is critical for our already freeze stressed plants. Some survival chance and growth can be increased with good moisture. Do not procrastinate.

Summary: Begin to prune and lightly fertilize (if none applied this year) plants showing new growth. Cut into live tissue. Take 2" off of boxwoods with no bark damage. The variation in plant damage between nurseries can be explained by protection offered by slope and tree lines, etc. New growth is not a guarantee. Damaged plants may still decline after July’s heat and drought. Irrigate what you can. It will help cold damaged plants more than you might realize, eliminating that stress. Plants are not likely to survive with a medium to dark layer around the cambium. Strong suckering is an indication the stem is gravely damaged. Do not destroy plants without written permission from your crop insurance company.

Landscape: Standard nandina, pecan, hickory, dec. magnolia, fringetree, tulip poplar have been slower to put out. The pecan, hickory and poplar are beginning.Begin protecting dogwood foliage from powdery mildew. Rotate fungicide modes of action.Let me know if it would hurt you financially to be unable to market Ligustrum sinense, L. vulgare, Lonicera maackii, L. morrowii, L x bella, Elaeagnus umbellata, E. pungens, mimosa, or multiflora rose.Save money by cutting your normal field fertility rate in half. I doubt that you will notice a difference in growth.

May your rain gauge runneth over.

Mark A. HalcombUT Area Nursery SpecialistWarren Co. Extension201 Locust St., Suite #10McMinnville, Tenn. 37110mhalcomb@utk.edu931.473.8484 fax 931.473.8089