I hope they flower this year at all, trying to be optimistic.

That is especially true if right after you planted them last year a late spring freeze occured in your area after they had broken dormancy, and especially if your area was hit with this year's late freeze around the Easter week that hit much of the country.

Now, all you can do is to feed them well and again after their first bloom. You also must make certain they receive at least 1 inch of good soaking rain each week, and if not give them at least that amount of supplimental watering. Finally, just wait until they bloom to see if your young CMS can recover those currently damaged tops of the trunks.

If they do not recover, then by late summer, the dead part of each trunk needs to be cut off, back to a bud which is growing fairly straight up and looks to be a good candidate to resume the role of becoming a continuation of that Trunks' multiple leader role.

Try to continue the feeding cycle as needed, but also make certain to end that feeding cycle in time for any new growth to harden off well enough that colder winter temps will not as easily freeze that newest growth.

I, too, recently planted four 3 gallon potted sized, Tuscaroras which suffered even worse than the description you gave about your CMs' damage, but there is one I planted 3 years ago which never showed any signs of winter damage to its three main trunks. The description of how I planted that tree and what factors were present to help it survive so well is described in the following paragraphs of this reply post.

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About 3 years ago in the late summer, or early Fall, I planted a three trunked, 11 foot tall Tuscarora Crepe Myrtle; to grow as to grow as a speciman tree at a friends house where a maple tree's 6 inch trunked Maple had been broke off, during a storm.

After the Maple tree's roots was pulled out of the ground, a large hole had to be filled. It took a half ton pick-up truck's bed filled with fertile sandy loam garden soil. Prior to filling the hole, mixed amendments into the clay soil found around the bottom and sides of the 10' wide and about 2'-3' deep hole. Then filled the hole with a mixture of the garden soil and 4 huge bags of Miracle Grow potting soil purchased from Sam's Warehouse. Along with all of that I also mixed in more slow release non-burning food.

After planting the Tuscarora in the very middle of this refilled Bed, I planted 4 "White New Dawn' climbing roses around the tree. For each of the rose bushes, I mixed into the soil a bag of rose bush, soil amendement. The Bed was finished off with a planting of a hedge of dwarf Youpon 'nana' holly which acts like a boarder to help contain the rose canes which grow long and are wrapped in a circle around the bed.

This Tuscarora I planted for my friend has not suffered any trunk die back at any time during the first 3 winters and early spring freeze events, after the tree was planted in the above described bed. The only reasons I can determine as to the health of the tree, is that the tree must have stayed very healthy and unstressed due to the fertile bed it was planted in; also due to how thick its trunks were when first planted; along with the tree being kept well watered with a soaking hose we had wrapped throughout the bed, around the tree and under the roses.

Yes, it can happen, especially if the plant was growing in a well protected area and made a lot of new growth late in the summer/early fall. Because this growth would not have hardened off as well as it might have done, it would be liable to cold damage over the winter. This sounds like what happened to yours.
Trim off the dead stuff, when you are SURE it is dead, trimming back to the trunk or to a larger-diameter branch OR to an outward facing bud. Doing that, you should avoid getting a mess of small growth, all from one point, as CMs will do after they have been "Crepe Murdered" or cut to a stub.

For an undamaged tree, my advice would be to cut off those new shoots that sprout from the root ball; in your situation though, any leaves forming on those otherwise considered trash shoots should become helpful to convert sunlight into more food for the roots.

my reasoning for such a conclustion concerns the potential for slight amounts of root deprivation, which your new trees' roots might suffer, depending on what percentage of the main trunks and branches have already died.

If you do choose to let those shoots continue to grow, and if you do not want the CMs to develop into huge shrubs instead of a nice clean trunked tree form; then early next year's spring, just prior to leaf bud-break, you could prune off those shoots.

New plants can be more sensitive to cold damage than older, more established plants are, it all "just depends". As the CM gets older, and if you manage to miss out on late frosts for several days next year, your CM should be fine in future years.

I believe the reason had nothing to do with the variety, but rather lack of moisture the previous fall of 2005 and drought in the early part of 2006. The tontos are planted on a ridge which tends to dry out more than the ones on the side of my property.

I beieve there is no typical winter die back. I am farther north than you are and other than that caused by the drought, I have had no winter die back in seven years. I have 175 crape myrtles on my property.

I simply cut out the winter die back. At first, I decided to leave it, thinking the newer, lower growth would hide the die back, but decided that the die would be unsightly and could leave a way for insects and disease to attack the crape myrtles.

One last thought, have you given them time to completely come out yet, we have had unusual cold weather at times this year. I have no sign of life on mine. Last year they were coming out about now. Trees and shrubs will start to green up lower on the stems before greening up at the tops. Of course, you can snap or thumb nail scrap the stems to see if there is any green.

I have 8 CMs. 2 had just begun to leaf out before Easter. The ones that hadn't yet started are only now beginning to show swollen buds. I figure I will have some tips of branches to trim off, but I am waiting to see, so it may be June before I am done tidying up my CMs.

Anyway, Laurie grower, about the question on your Tuscarora, funny you should ask as it just dawned on me about the condition of my Tuscarora--why it isn't doing as well as the others. According to this link, I found out that Tuscarora is susceptible to winter damage and may be heavily infested with aphids. Now I'm thinking of replacing it with an Osage because what I'm most afraid of is that it will attract aphids and then have them spread to my surrounding plants.

Since I'm a newbie with gardening myself, I would appreciate any further feedback here.

http://www.clemson.edu/crapemyrtle/tuscarora.htm