Azaleas (and rhododendrons) are extremely sensitive to aluminum toxicity so keep the aluminum sulfate well away!! If you need to fertilize (if soil pH is good they rarely need any), use cottonseed meal which is a natural acidifier. Or something like Espoma HollyTone.
All evergreen shrubs will have leaves that age, change color and drop or fall and that can happen rather randomly. It is not something that I'd be concerned about unless it happened in quantity. That shriveled shoot in the first photo could just be the result of the aluminum sulfate. Just snip it off.

All in all, your plants looks pretty good. But stay away from any aluminum products!! And all those other chemicals and fungicides. You don't need them and they are likely doing more harm than good.

I agree. No aluminum sulfate on azaleas or rhododendrons. When newly purchased, I use cottonseed meal on my Encore's (in the Spring only) for a few years. Since they are not heavy feeders and my soil has no issues (it is not sandy for example), after 2-3 years they start looking established and I let them feed off the decomposing mulch only. They probably will be fine even w/out the fert.

I see some old leaves falling in the pictures but not many. Unless there is an increase, I would assume they are dropping old leaves.

There are voles and chipmunks that can nibble at roots so keep an eye for pests.

I would not use pesticides or fungicides until I can confirm that a pest/problem is present and can identify it. Why did you select those two products??? What animals or insects have you seen?

Leaf wilting is usually a sign that the plant needs more water. But this symptom is not localized to a specific area and occurs randomly throughout or in all branches.

You did not say where you are or your zone or when did you plant the 18 azaleas. I was wondering if winter injury could have caused some dieback. It can happen in their first winter, specially if it is too cold or if winter was cold and dry. I would also look for azalea borer damage or bark split.

Check your soil acidity now and then if your soil is alkaline. There are some large but light green leaves in the bottom picture. They could be new foliage and it is normal then.

It is good to know that the azaleas have lots of new growth and are blooming well! I hope they keep that up!!! ;o)

The azaleas have lots of new growth and are blooming well.

==>>> then what are you fixing??? ... they look pretty good.. and on some level i think there will never be instant gratification on whatever you are trying to fix ... with shrubs ... whatever you fix today.. may not show until next year ... and in the meantime.. the ugly damaged leaves will continue to color and fall off ... but that doesnt mean.. you keep trying to fix it.. because you probably already did ..

were these just planted last year??? ....where are you .. what is your native soil.. when were these planted .. how did you plant them .. how did you water them .. was this the first winter.. what was winter like.. is the fence south facing ...

im wondering about your stock.. was it potted and rootbound???

im wonder about timing of planting ... did you do this in the heat of summer??? .. did you water them deply thru the root mass planted and then allow near drying .. before the net deep watering ...

im wondering about a dry winter.. or winter winds ... depending where you are ... or winter sun on winter dormant plants ...

whatever happened.. imo.. it was minor.. and you are showing some leaf damage.. which is not uncommon after their first winter ... and once a leaf is damaged.. it looks bad.. until they fall off .. so be it .. just like deciduous trees in fall .. but we dont treat them .. they just fall off ...

frankly.. they look better than most i ever grew here in my COLD winter MI ... and its normal ... they are what they are ...

lastly ... one of your issues is that you planted a monoculture.... so all the plants look either good or bad .... all at once ... so you start freaking out ... over time.. if some start failing.... replace with something else .... just to add said diversity ...and to reduce your stress when one type of plant has a bad winter ....

and frankly ... with all my experience.. if i planted 18 of anything.. i would expect a loss or two ... its just the way it is ...

ken

ps: i NEVER fert trees or shrubs .. imo.. fert is just a waste of money ... they are plants..not children ... and if you need to balance pH or something.. that is a soil amendment.. and should be dealt with as such... not thru fertilization ...

Thanks for all the replies. I used aluminum sulfate and blood meal because many many years ago a local nursery told me to treat my struggling azaleas with it. The combo made a tremendous difference. That was a different time and different place.

I live in North Alabama and my soil is clay. We planted the azaleas in the pics in October 2018. Last year the azaleas struggled just about all year until I add irrigation to them in the late summer of 2019. Last spring (2019) and this spring (2020) are in the top 5 wettest springs on record here. I used those two different fungicides because not a lot of air flow on the azaleas up against the privacy fence. The azaleas sit on the east side of the fence and I didn’t want it to be a fungus causing my problems. The systemic pesticide works great at keeping plant eating bugs at bay and its much better than a foliage spray. My setup here is 3 azaleas along the fence then a crape Myrtle, 3 azaleas then crape Myrtle, keeps repeating the entire length of the fence (125ft). Last year we got aphids bad on the crape myrtles and the trees were turning black from the fungus which grows on the sugary excrete. The systemic treatment worked great killing all the bugs, so I treated all the plants in this area with the dominion 2L this spring.

Do you all think I should treat the soil to ease the aluminum toxicity or just let it runs it’s course? I’m definitely going to get a soil test.

Thanks again!

Some times, it is best to do nothing.

Years ago, I too accidentally added some aluminum sulfate to an azalea before my brain said Oops. It was not much and the plant did not negatively react in any way. So if your a/s concentration (I assume you followed the product label instructions and not applied more than recommended) was as light as mine, they may be ok.

But how to know for sure? When you send for your soil test ("I’m definitely going to get a soil test"), ask this very same question. And ask at what levels would they consider you have aluminum toxicity in your clay soil. They can tell you for sure.

If your nursery recommended a/s, it may have been due to iron chlorosis and alkalinity in your soil. But while a/s is a quick soil amendment in a list of very slow acting amendments ;o) since you have azaleas, I would have used instead garden sulfur, composted manure, organic compost, greensand or iron-chelated liquid compounds sold at your local nurseries to address iron chlorosis.