Crape myrtles do best in a soil pH of 5.0-6.5 which is pretty acidic. Most soil in Utah is quite alkaline. It may be possible to get some of the varieties that grow in your zone to survive with the use of something like blueberry fertilizer, or some other for acid loving plants. I'd talk to a knowledgeable person at a nearby nursery. Be aware that you can acidify your soil, but more than likely, your water is also alkaline.

It might be easier to find a substitute for myrtles that will do well there ..unless you just like a good challenge.

Crystal

Tonya,

Take a look at the link below. I think people grow them in St. George, but it's very risky around here. There is a variety they mention that's hardy to zone 6, which is much of this area. Some parts of Salt Lake Valley are zone 7, which is the bottom of their range for the regular varieties. They say they may grow OK in zone 7 but die back to the ground in hard winters -- they'll grow back, but they won't likely get very large here.

I do recall seeing a few crape myrtles at Temple Square -- they grew as shrubs, probably because they couldn't get big enough with occasional die back in hard winters. They eventually removed them, so they probably weren't performing as they wished.

Anyway, if you have a good microclimate, like a sheltered spot along a south wall of the house, you might make them work, but probably only as small shrubs that can handle an occasional pruning back to ground level when winter kills their above-ground growth.

Here is a link that might be useful: Crapemyrtle fact sheet

I agree with the call on marginal hardiness. The ones that I have seen my neighbor grow has never exceeded 3 feet in height. As far as the pH I don't believe that they need 5.5 nor are they as sensitive as blueberries. If I were putting them in this year now I would be sure to mulch them well.