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Help with plant problems, please?

Posted by redding (My Page) on
Fri, Jul 22, 11 at 0:55

Can anyone help me solve these two problems?

I've managed to save the poor little dying buddleia bicolor, I think, since I put it into a jumbo pot and moved it into dappled shade. It was all but dead from the hot sun and clay soil. It has put out new growth now to replace what died, but the leaves look bad. Faded and mottled and just not happy at all after a few days. Is it chlorosis, or what? Does anyone know?
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Also, does anyone know what will cause cause canes on a hibiscus moscheutos to die back like this? I lost one entire plant this way last year, the beautiful big Luna Red one. It started one cane at a time, and then got faster and faster until it was gone. I had hoped it might come back this spring, but no such luck. This is a solid pink and I don't want to lose it also.
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Any ideas?

Pat


Follow-Up Postings:

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RE: Help with plant problems, please?

Pat,

Is it the new leaves? Are they quickly turning mottled and fading shortly after they come out? If so, I'd check the back of the leaves for spider mites. Sometimes red spider mites leave mottling and stippling on foliage, and the spider mites are quite abundant this year. I'd also look for whiteflies, but spider mites would be my first guess.

With hibiscus moschuetos, the kind of dieback you are seeing can be common in hot weather. I don't necessarily think it is a disease. Remember that they adore constantly moist but well-drained soil, and abhor drought and poorly-draining clay. The worst combination for them is heat/drought and dry clay. I do grow them in clay with no problem, but it is wet clay on the pond bank (well, normally it is wet there) and in our swamp where I planted them on the uphill side of the swamp so they'd be moist but not swimming in standing water.

Down in my veggie garden where I have Disco Belle and Southern Belle in well-improved sandy/silty/humusy clay on the semi-shaded northwestern edge along the veggie garden fence, they usually do quite well but are struggling this year because there are no living veggies in that section and it isn't getting watered. I try to remember to water them once a week, and that is keeping them alive, but not necessarily happy.

I did have a lot of trouble the first couple of years here with them being killed by cotton root rot, which is a horrible issue, particular in any soil where cotton once was grown, but after working exceptionally hard to amend the soil in the area where plants kept dying from CRR, I have grown them successfully ever since. With CRR, though, the entire plant dies, and you will see the disease progress right up a row of plants killing them one after another after another.

Your plants might be getting too dry. Mine had a little dieback on a couple of limbs just like yours during the two weeks we had a very high number of fires and I was away and didn't water them. I have watered them twice since I noticed the dieback and there's been no further dieback and the plants are putting out new foliage, so hopefully I started watering them in time to save them.

Dawn


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RE: Help with plant problems, please?

One of my forsythias is doing the same thing as your hibiscus. It's confusing because my other forsythia in the same row of shrubs is on the same watering schedule and looks great. I'm not sure why only one would struggle. :/


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RE: Help with plant problems, please?

Thanks again, Dawn. The hibiscus is in a pretty sandy location with good drainage and I do try to keep it thoroughly watered. Maybe it's just the heat that's doing it. I have a feeling that the two we lost last year might have been caused by the jumbo gopher I had working in there, although one of the plants appeared to have rotted off at the crown.

It would not be a huge surprise to learn that the dreaded spider mites are now attacking the buddleia. If that poor thing manages to survive after all it's been through, it will be a miracle. What's the best thing you can recommend to use for spider mite control? I know I have them in the veggie garden. They moved in just this past week. I think this evening I'm going to go out with the clippers and cut down everything that's infested and then dump all the stuff into big lawn and leaf bags and seal them shut. That should take care of all the ones I can see, shouldn't it? I certainly don't want to leave anything around that could continue to contaminate the rest of the plants. Then if I can spray the remainder, maybe . . . . . . .

If you can recommend a spray, and I don't already have it on hand, I'll be headed for the store this afternoon to get some, believe me! I hate to use the chemicals, but I think it's time for the big guns, while I still have any garden left to worry about.

Pat


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RE: Help with plant problems, please?

Here is the only way to get rid of spider mites when you have an infestation:

Pull the plant, put it in a black plastic bag and set it in the sun for a few days. That will rid the plant of spider mites. Mostly it just feels satisfying after trying so many wasted attempts from hand washing each leaf with insecticidal soaps to spraying the toxic sprays that say they get rid of spider mites and killing yourself in the wasted effort. They ALWAYS come right back in a couple days. Always.

Some years are just bad for them.

Avoid any plant in the future that says its prone to spider mites. Marigolds are notorious, for example.


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RE: Help with plant problems, please?

Janet, that's actually what I just did. I left the bag sitting in the sun in the garden and a few minutes later was very gratified to find that the temperature was approaching orbit range. I'd like to think I'm cooking all those greedy little beggars! As you said, it's a very satisfactory feeling.

They are now moving on to my pepper plants, and I am declaring WAR! The peppers are just about the only thing that's producing well. I just broke my own cardinal rule of not doing any overhead watering during the summer, and gave everything a nice hand-held shower. Kill or cure at this point. I should have the Ladybug spray by next week, but I may or may not have any garden left to use it on.

The tall African marigolds I planted are supposed to be resistant to disease, but that was in the original form. I imagine that they have been hybridized now to the point that they're no longer effective as insect control and are simply insect magnets instead.

Last year it was the worst infestation of whitefly in the lantana that I have ever had the misfortune to see, and now the spider mites in everything else. I suppose I need to go out and examine my poor struggling young maple to see if the mites are also attacking it. The tree is 5-6 years old and was just getting a really nice shape to it. I'm going to be really cross if I lose it.

Pat


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RE: Help with plant problems, please?

Spider mites outnumber people in rural Oklahoma about a billion to one, so I just ignore them. There's no way I am going to be able to control them in any shape, form or fashion. With thousands of acres of wildland all around us, they're simply everywhere and on everything. I plant what I want and what I like and enjoy my plants whether they get spider mites or not. While most of the plants in my veggie garden have had spider mites on them since April, the mites are just now showing up on my marigolds. Some years they hit the marigolds first. I don't see any rhyme or reason other than the fact that the hotter and drier it gets, the worse they are.

Spider mites are just a fact of life here. Even though they bother a lot of my plants, they generally don't kill them. Even the tomato plants that have heavy infestations of them and which are not receiving water still are pushing out new growth at the top of the plant and are blooming and attempting to set fruit, even though they are covered in spider mites. I'd pull the plants and dispose of them, but every time I step outside the fire pagers go off, so I'm staying inside today in the hopes that we'll have a quiet day instead.

I don't know how easily or rapidly spider mites spead in a more civilized area, but here in our rural area there's just so much native pasture land and woodland around that they move freely as they choose with nothing to stop them.


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RE: Help with plant problems, please?

Well, I'm glad I read that post before I went back out to the garden! I was just about ready to yank out half of my squash and tomatoes in an effort to slow the mites down.

You're right. I live in a very rural area with vegetation everywhere. The thicket across the street is so dense that I don't think you could walk through it, and there are cedars, oaks and willows all around the garden area. It's a losing battle for sure.

At least now I won't be in quite such a panic over it. I did pull up and destroy the worst of the marigolds. They were just big fuzzy blobs of infestation. But I was afraid I might also have to get rid of some of the tomatoes that are just now trying to produce.

The good news is that, as much as the damage on the squash looks identical to mosaic virus, it's also apparently mites. I'd a whole lot rather have them than to think I've gotten mosaic in there. That would be a nightmare, but I examined the leaves really closely this morning and it looks like mites after all.

I do so hope you have a quiet day with some reprieve from the fires!!

Pat


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RE: Help with plant problems, please?

I never plant marigolds. They always get spider mites. I don't plant anything susceptible to mites, rust or powdery mildew. You can look up any plant and check in advance and save yourself the grief. Its just asking for trouble to plant certain things.

One thing I don't like about Crepe Myrtles is they get white mold on the leaves when its humid and they are prone to aphids. I had one dripping syrup in my courtyard onto the tiles for three years with ants continually marching in a long line toward it to lick up the syrup and finally dug it out after getting tired of spraying and cleaning up the sticky mess.

Sorry to bring up the myrtles again.


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RE: Help with plant problems, please?

It's hard not to bring up myrtles when they're just about the only thing blooming right now. Although my cosmos is really happy too.


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RE: Help with plant problems, please?

My myrtles seem to be doing okay, even though the blossoms are getting pretty crispy in all this heat. The monarda that's under them completely quit blooming very early, and the spiderwort that's in the sun is a total disaster. Smaller ones that are getting some shade are still in decent shape. The coreopsis is okay, but hardly what I'd call thriving. The new baptisia seems to be okay, as are the new white sage and the perovskia (which is actually a perovskia this time, instead of a mystery plant). The bearded iris are about normal for this time of the year, in spite of the grasshoppers, and they look a whole lot better than the ones in a garden a few miles from me. The salvias and lavender seem to be the happiest, but the biggest surprise of all is in the peonies. The foliage looks terrific on them. I thought they'd really be suffering, and they aren't.
Of the hybrid roses, the Pinata is suffering the least by far. The others are alive, but they don't look happy. Both the Goldflame and the Montezuma honeysuckle are struggling, although they're alive and will recover if it ever cools off at all.
The grapevine that I found on the property and transplanted to the front fence appears to be thriving. I'm pretty sure it's something that someone planted here years ago and then totally forgot it. Why it survived under a succession of owners and zero care is some sort of miracle. Eventually I may see what sort of a grape it is. For now, it's a vine.

Sheeeeesh. Here I go, writing a book again. Sorry about that.

Pat


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