I thought this info from Tony Avent of Plant Delights Nursery might be informative and helpful to those suffering plant damage from the recent spring low temps in parts of the U.S. About the fourth paragraph down he talks about plant physiology and prospects for recovery.

Tony Avent, Plant Delights Nursery:

"We made it through winter in great shape, but then early spring jumped

up and bit us in the you know where. Gardeners in many parts of the

country were hit with devastating cold in early April after spring

temperatures had already fooled many plants into beginning to grow. Web

ordering provides us with a fascinating glimpse into gardeners’

real-time state of mind. Everyone was going crazy ordering during the

warm first week of April, only to be shell-shocked days later when the

cold weather returned. We can see folks just starting to recover enough

to think positively about gardening again...perhaps we need an on-line

gardening therapist to help with the recovery...where is Dr.

Philadelphus when you need him?

In Juniper Level, we had been in the 80's for two weeks, before

encountering five consecutive nights below freezing with the worst night

reaching 22 degrees F. A couple of days later, we got to enjoy a

smashing hailstorm, followed by an entire day of 50+ mph winds. I know

this is a typical spring day to many midwest residents, but in our neck

of the woods, it’s a big deal.

Although we covered quite a few perennials in the garden and kept the

damage to a minimum on those plants, the trees and shrubs were not as

lucky. Magnolias, celtis, crape myrtles, and idesia were fried to a

crisp. I read a laughable article in our local paper just a day before

the freeze explaining how native plants would not be hurt and how they

should be planted instead of plants from foreign lands. Guess

what...native oaks, walnuts, fringe trees, redbuds, maples, and many

more look like my darkened efforts to cook toast. I guess I should have

let my native plants read the article.

Now it’s a matter of wait and see if the plants will recover. Many of

these plants have dormant buds along the stem, which under normal

circumstances would not develop. The plants must first get over the cold

shock, then we will learn if the physiology of the plant will allow the

dormant buds to develop without some additional stimulus such as an

additional number of chilling hours. In many cases, the death of a

terminal bud may be enough to change the hormonal balance that often

keeps the dormant buds from growing. In any case, it will take 2-8 weeks

of warm weather before we will know for sure what to expect from our

plants. There will be some cases where the plants only sprout from the

base and others where they may be completely dead. Not only is each

plant different, but the physical state of each plant is another part of

the equation. Plants on the north side of a building may have remained

dormant and avoided damage, while the same clone in a warmer location

may have been killed. Many nurserymen who had recently dug balled and

burlapped crape myrtles actually saved their plants. The process of

digging and root removal caused the plant not to begin growing as early.

These dug plants are mostly fine.

It seems that nursery growers in the wholesale production regions of

Tennessee got hit the hardest, with several growers suffering losses in

the 100,000's of plants as temperatures dropped into the mid-teens after

many plants were in full leaf. Our thoughts go out to them during what

will be a financially difficult time recovering and staying in business."