slowly everything is dying Humidity? Fungus?

I live around Houston, TX and last year I had two butterfly bush, rosemary, thyme die the exact same way. The leaves from the bottom up curl up then turn yellow, fall off and then the plants die. I bought 3 encore azeleas around the same time and all three started doing the same thing. They did not die, but they lost all their leaves. Another butterfly bush suffered also, but did not die. Last summer we had so much rain and humidity I assumed it was a fungus and sprayed. I had to spray a lot and keep the infected leaves all picked up just to keep the last butterfly bush from dying. Now my iris are looking horrible and I am wondering if anyone in my area is having the same problem. I know rosemary does not like rain and humidity, but this was a 5 year old plant, that has always done just fine. Also I have a lemon tree that is doing the same thing.

I don't have any answers for you, but I had the same problem with several of my butterfly bushes in the past three years, and a couple of my spireas. It was only the ones that were planted in one particular bed.

The first year I thought it was just a weak bush, so I added fertilizers etc. They died anyway. Then I worried that I over-fertilized (even though it was with organics) so I dug out pretty much all of the dirt and started over with new plants and new soil (amended) from another part of my yard. The same thing happened. The third year (I know, I'm starting to look stupid, or at least excessively obstinate) I changed varieties of butterfly bushes and also added roses. So far this spring the results seem to be that the roses are extremely vigorous and happy, but the jury is still out on everything else. At least one previously healthy blue mist spirea that had gone through all three years apparently untouched is 3/4ths dead.

I really don't know what all this means. Soil fungus? I live in the high desert, and have very sandy soil. It seems unlikely that it is an airborne disease, since identical plants (some of which are seedlings or "siblings" of the now-deceased plants) are thriving in beds a stone's throw away.

I hope it helps you to know you are not the only one--I thought I was the only one! Everything I read says butterfly bushes are indestructible and untroubled by pretty much anything, but it seems like something is going on...I hope someone has some answers for both of us!

For the rosemary, thyme, and butterfly bush it could be too much water/humidity, they are all fairly drought tolerant so if you had a ton of rain I could see that wouldn't make them very happy. Azaleas need more water, but they're not going to want permanent wet feet either so if you had enough rain that could have been bad for them too. I don't think it's the sort of fungal disease that you can spray for, those typically are somewhat selective in what types of plants they infect, and since you've got a bunch of affected plants that are no way related to each other I suspect if it is fungal it's related to water/moisture, and those sorts of problems unfortunately can only be fixed by getting things drier, which can be hard when Mother Nature is working against you!

mudpiegirl--even though your symptoms sound similar, given your dry location I really don't think your problem is the same as cottagestyle's. What time of year have you been planting your butterfly bushes? If you are planting them too close to when the weather gets hot that could be most of your problem. That doesn't explain your Caryopteris...but I've found that they sometimes die back a little over the winter and also can get kind of ugly if you don't prune them, so is it possible that it's one of those things and it's not really dying?

Well, for the first plants, they were all established and growing well for at least a year before showing any signs of anything. (In the case of the most recent caryopteris, it was more than 3 years of healthy growth). I always cut back back my caryopteris and butterfly bushes by 1/2 to 2/3. The die-back is all the way to the roots. What I noticed is that one plant after another started showing the signs that cottagestyle was describing-- curling, yellowing, then brown and dying. This happened in the middle of the summer but the plants had been planted the fall (in the first case 3 or so years before, and in the case of the replacement plants/soil the previous fall) and had been growing well up until that point. I am really perplexed.

I don't suppose you have any pictures? I still think cottagestyle's problem is caused by too much water/moisture and I don't see how that would be possible in your climate, so unless you're really heavy-handed on the watering during the summer I think yours is a completely different issue.

I'll throw out some suggestions for the various things that I've seen kill or damage established plants in my garden with symptoms that sound similar to yours so you can see if anything sounds like a possibility.
1. Underwatering. I don't run into this too much since I have clay soil, but for your plants, once they've gotten bigger and their roots have gone down into your sandy soil rather than being in the nice amended soil you planted them in, they may not be finding much water down there.
2. Overwatering. Less likely for you given your soil/climate but not impossible. And many drought-tolerant plants are susceptible to root-rot fungus if they get too much water when the soil's warm. I grow a lot of California natives which are adapted to our wet winters/dry summers, in winter when the soil's cold the root-rot fungi can't really grow so the plants can handle being in wet soil, but when the soil warms up then the fungi can grow so if you water even a little too much you can kill them. Your plants will be a bit more forgiving than that, but if you do water a lot it's certainly a possibility worth considering.
3. Gophers (or other underground root-chewing critters). From time to time, I'll see a plant that was looking gorgeous and healthy start to wilt, then the leaves dry up and the plant often dies. When I go out to investigate, I'll find that it's missing most of its roots.
4. Scale or other sucking insects. I've had a few occasions where I didn't notice the scale until the plant was already wilting pretty badly, if you let it go too long then the leaves would yellow/dry/fall off
5. Spider mites. This is actually a strong possibility in a dry climate like yours, they aren't particularly picky about which plants they eat, and they spread easily from plant to plant so it would be very easy to see if you don't catch it how everything in a bed could wind up with them. And if you don't treat them, the leaves will eventually do exactly what you're seeing. They make a telltale yellow stippled pattern on the leaves...if you keep an eye out for that then you can catch them early before they kill anything, but if you're not really looking for them and they get out of control you can lose a ton of plants (and the stippled pattern is only telltale if you're looking closely at your leaves...in a garden bed if you're not examining plants carefully it could be easy to overlook until it's too late). I lost a bunch of container plants to them a couple years ago before I recognized the signs of their damage...now I know what to look for so I can catch them early and get rid of them before they do too much damage to the plants.

Good information, ecrane3. You ladies might want to contact your local extension agent with this problem. They should be able to help you with it.

I don't have pictures, unfortunately. I don't think it is a watering issue, especially since the same plants in nearly gardens are doing fine and are on the same basic schedule. I do have a mole problem in my yard,I have lost a couple of plants to that critter, because of it's disturbing the roots without me noticing. But the mole hasn't been hanging out where this problem is. Scale isn't such a problem here. We have a huge grasshopper problem, but they will just defoliate the whole plant. Spider mites could be the problem, we do get them, and sometimes bad. They are really hard to see and it seems like it would be possible not to notice them, especially on a plant that is already silvery so it would hide their webs. I wonder why they would be in such a localized area, though.

Since I planted a different variety of butterfly bush last fall and so far it seems to be coming up ok, I will keep a very close eye on it, and also what's left on the caryopteris that was so badly damaged over the winter, to see if I find any spider mites. That sounds like the most likely cause I've heard so far. Thanks. Do they not have spider mites in Houston?

Thanks for your help. I will see if that is the issue this summer!

mudpiegirl, I sometimes think spider mites are the Virginia state bug!! Pesky critters!!!

Spider mites don't like humidity, so while they're possible in Houston it's less likely and since cottagestyle had so much rain and humidity last year I think it's much more likely her problems are fungal

I do think spider mites are a strong possibility in New Mexico though. And anytime I've had them they are always very localized...one plant will get them and then they'll spread to any of the plants around that one if I don't catch them fast enough (don't ask me how they got there in the first place, most of the time when I get an infestation it's on a plant that I've had for a while with no other new plants around it, so they're not coming in on things I purchased).

Spider mites are very abundant in Houston. :-{
I have a question for you, cottagestyle. You live in New Caney - so we have basically the same weather and planting conditions. What kind of soil do you have, and do you have raised beds? What kind of irises are you growing?

Hi ceejaytown All the soil is pretty neutral and rich in organic matter, I started new beds about 6 years ago so none of it is clay. I dont know about the irises, its the ones with the purple flower, they are all over my yard. I only had that bunch look bad. My only butterflybush left looks bad already, leaves are turning yellow and falling off. I think since we had all that rain last summer I must have got a fungal disease, and I am thinking it is somehow in the soil. I have replanted some roses and dahlias in the bed that 2 butterfly bushes and rosemary and everything else died in. So far nothing I planted is doing well in that bed. I am watching carefully. I clean up the leaves everyday and keep everything clean. It's driving me crazy. I will try to post more pics. Thanks everyone for your help.