Do your plants get morning sun in their E location...that can be very hard on azaleas - early morning winter sun can damage frozen leaves and buds.

I'm curious too as to why you added lime for these low PH shrubs...my acidic clay is amended with compost, but nothing else. Which brings me to the fertilizer. Fertilizing at planting time is generally not good, and these shrubs have low nutritional requirements - overfertilizing will make them more susceptible to winter kill. I'm not growing Hilda, but my book says winter hardy to approx -5F...colder than that and you may have to consider winter protection.

I know some nurseries rate azalea "Hilda Niblett" for Zone 5, but it is also only hardy to -5F which is not a good fit for your location. I live in zone 6 in SE PA and would not expect good luck with a plant rated to -5F. The coldest temperature we have ever had is about -10F, but because of the summer sun and winter cold, I don't expect anything more tender than -15F to survive.

Evergreen azaleas take a while to develop their cold hardiness. In general they don't develop their lowest cold hardiness until they are three years old. I always protect them from winter wind and winter sun for the first three years and even longer if they aren't doing real well.

Applying lime is a strange thing to do for azaleas. Azaleas like an acidic soil and do need calcium, but they can get it from gypsum which does not raise the pH.

When planting in clay, a large hole is very good, but also it should be mounded up and the plant should never be planted any deeper than originally planted. Good drainage is mandatory.

I think that evergreen azalea will always be a challenge for you. Here are some hardy low growing evergreen azaleas that may work for you.

Bixby, red, -20F, 2'
Helen Curtis, white, -20F, 2'
Hino-red, red, -20F, 1'
Hino-white, white, -20F, 1'

Here is a link that might be useful: Evergreen Azalea Reference List

Saluki,

If your Midwest soil is anything like mine, lime is the last thing you'll want to add! Do whatever you can to make an acidic soil mixture--peat, shredded pine bark, pine needles, a yearly sprinkling of elemental sulphur.

I agree with Rhodyman, evergreen azaleas are a bit of a challenge around here. So far I've had excellent results with 'Herbert', 'Karens', and, in a protected east side location, 'Stewartstonian'. I've had a terrible time with 'Girard's Pleasant White', and would love to try 'Helen Curtis', but no one around here carries that variety.

For a similar look, you can try the dwarfy lepidote rhodies such as 'Ramapo' and 'Purple Gem'. They've been really cold-hardy for me. They are pretty common at both the good nurseries and the big boxes. Of course, you can always get good cold-hardiness from deciduous azaleas, and all kinds of wild flower colors to boot!

A.J.