Crepe myrtles don't need fertilizer. It is a myth that trees and shrubs must be "fed" in order to thrive.

You shouldn't be seeing buds in April! Crepe Myrtles are late to break dormancy in Spring and they do not bloom until mid- to late-summer; their buds come well after they leaf out. Just sit back and relax; there is nothing to worry about right now. Take a deep breath. The green inside the twigs is a good sign -- the tree is alive and should be breaking dormancy soon. You shouldn't see buds for at least another month and probably two months depending on when your particular variety blooms.

If I may tweak mista 's comment regarding fertilization, there are often reasons when fertilization is beneficial. But it shouldn't be thought of as a mandatoty routine practice.

You can rest assured that Crape myrtles are often the last deciduous tree to leaf out in the spring. ( I understand that you mean leaf buds, not flower buds.) One morning you'll wake up and the trees will be covered with little leaves.....in a couple of days, in full foliage.

If I may tweak mista 's comment regarding fertilization, there are often reasons when fertilization is beneficial. But it shouldn't be thought of as a mandatoty routine practice.

You can rest assured that Crape myrtles are often the last deciduous tree to leaf out in the spring. ( I understand that you mean leaf buds, not flower buds.) One morning you'll wake up and the trees will be covered with little leaves.....in a couple of days, in full foliage.

^ Good point rhizo. My point was really meant to be crepe myrtle-specific -- they don't have a particular need for fertilizer, all else equal.

I would say that there are circumstances in which you might need to fertilize a tree or shrub (e.g. if you are in a dense urban area or an area with very sharp draining soil). There seems to be a perception out there that all trees and shrubs must be fertilized or they won't flower or grow well, which is not true. Most trees and shrubs don't need any supplemental nutrients in most soils. A little 10-10-10 slow-release fertilizer is cheap insurance that your soil has plentiful nutrients, but I wouldn't consider it necessary.

Thanks mistascott and rhizo.
It mystifies me how I can pretty thoroughly research a topic (such as crape myrtles) just before purchasing and planting ... and how most of that information has left my mind the following spring!! ;0) Thank you both for the reminder regarding blooming time which is directly linked to the buds. The varieties I planted are 'Catawba', 'Dynamite', 'Natchez' and 'Tonto'. After considering bloom color, growth habit, bark and mildew resistance, these were my favorites ... and I was fortunate to find them late last September. Again, I appreciate your advice.
mistascott, where are you located? I'm just outside Roanoke. The zone charts insist on calling us zone 7 but, being only a stone's throw from Blacksburg's zone 6, I've always erred on the conservative side.
gary

I am in northern VA (Manassas area). I find it very strange, given the elevation in Roanoke that you are in 7 and we are 7 up here too. There even appears to be parts of the Roanoke area that are 7b and we are only 7a here. I wonder what sort of micro-climate exists there? I am very intrigued.

Hi mistascott
Very intriguing, I agree. I'm actually in Daleville, approximately 8-10 miles (as the crow flies) northeast of Roanoke. According to the Agricultural Research Service of the USDA (as recent as one year ago), Roanoke is in the 7b plant hardiness zone while we are in 7a. The elevation doesn't change between the two; I suppose those 8-10 miles northeast is the answer??? Christiansburg, about 32 miles west of Roanoke, falls to 6b; that's understandable, since the elevation is significantly higher. Blacksburg, even higher, is also 6b. Manassas, as you mentioned, is 7a.

But now is when it gets crazy. According to the National Gardening Association, both Blacksburg and Christiansburg jump up to a 7a; Roanoke falls to a 7a; and Clifton Forge (30 miles north of me with the same elevation) drops from a 7a to 6b. That's all wrong. After spending time in Clifton Forge in all seasons, the temps are nearly identical to Daleville and, compared to Blacksburg and Christiansburg, it's a tropical area. In Clifton Forge, you need sunscreen; in Blacksburg, a parka.
Moving on to the Arbor Day Foundation (which omits the "a" and "b" designations) Manassas and Christiansburg drop to a 6-7; all the others are 7. Which is to say that Blacksburg, tucked away up in the mountains, is now higher on the scale than Manassas. And, to end this madness, it appeared (to me) that the National Gardeners and Arbor Day are drawing their information from the USDA.
Intriguing, I think, is far too mild of a word! :o)

Arbor Day did their own thing without reference to ARS or the USDA map.

The zones in the current (2012) map are 5 degrees each, a and b. So if you are at 4 degrees F average lowest temperature you are in one zone and if you are 6 degrees F you are in a different zone even though there is only 2 degrees difference between the two.

On the interactive USDA map you can get the actual average low temperature as well as the zone number. I found it as 6B at -1.0 degree for Christianburg. East of Blacksburg was zone 7A at +1.8 degrees F. The west side of Blacksburg was 6B but at -2.7 degrees F. bTotal differences in temperature about 4 degrees.

The new map can see microclimates as small as about 1/4 mile square.

The new USDA map is based on much more sophisticated math and a much bigger database than anything ever done before.

All of that aside, onothing is going to be more knowledgeable about your own garden than you.

I was actually part of the team that created the new USDA map.

Wow! Now I know why I should have paid more attention in math class. Two degrees difference between two zones is what I'd call "fine tuning it". A big congratulations, kimka, to you and your team. The new map is a far cry from the solid bands of different colors that so many of us swore by. (Still, it feels like I'm freezing my buns off more in Roanoke as compared with Daleville.) :o)
BTW, I heard (or read or dreamed) that something had been done that took into account high temperatures. It would aid in determining what plants were not suited for specific higher temps. Is there, in fact, a chart/map of this sort?
gary

American Horticultural Society did a heat map based on high temperatures, but it is pretty simplisitic. It only takes into account the average number of days each year that a given region experiences temperatures over 86 degrees (30 degrees Celsius). That is the point at which plants begin suffering physiological damage from heat. The zones range from Zone 1 (less than one heat day) to Zone 12 (more than 210 heat days). But it does not include wet or dry heat which makes a major difference and other points.

Here is a link that might be useful: AHS Heat Map

A lot of people still post their old USDA zone here, but the new ones are much better as mentioned.

Still strange why parts of Roanoke are 7b. Could be historical data, but I wonder what about that area makes it 7b because most of Virginia is 7a or colder except the Tidewater area. Interesting mystery.