Petunias dying soon after planting..

I know it is July--I also know that we have had a horrendously hot summer (High 90's)
with almost daily drenching rains. This has been going on for about 2-3 weeks now.
The gardens are suffering--and many things are giving up the ghost...

However--I have tried to plant some petunias where there are some open spots--
most of which already had petunias in them that died a similar death.
These have been purchased from different sources and all looked
OK when planted, Then, within a week, they just shriveled up and died...
The stem were void of leaves--just looked dried up and dead.
Other plants nearby were not affected--even other petunias planted earlier.

OK! I know it is end of season--and, even at Nurseries, the plants are so-so.
Good deals to be had, though--and the flowers look OK--so I buy them.

One person suggested I may have nematodes in the soil--but this is happening
in 3 different beds a good distance from each other.

Could I have someone's educated guess what may be going on here??
Just FYI--I am a seasoned, informed gardener--but am lost in this case.
WHY is this happening????
Thanks, Gita

The last picture is so sad---these have been blooming beautifully, and now,
on the sunnier side, after another 2 days of rain--this is happening.
I really think, just in this case, they are simply dying from all the heat and water,,,
The same blue petunias, on the other side, are still OK. More shaded...
Pic. #4 shows the bed as it was...

Thank you, Gita

I have the same problem. I beleive its Phytophthora crown rot. Classic of hot dry conditions after wet warm weather. Remove infected plants. Dont replant in same area. Protect non infected plants with a broad spectrum fungicide such as chlorothalonil.

Pictures: a couple of my infected plants and one healthy one.

Dr. O--
Goodness! They sure look the same!! You are not far from me..One state up.
We just have not had "Hot dry" conditions....mostly Hot WET!

Should I assume it came WITH the plants? From the Nursery/Growers?
I have such a load of flowers in one of the beds...and these seem to be
the only ones dying off...that i can see...
The Petunias I planted earlier (Mid May) seem to be OK. How come?
Same weather conditions...same beds....

I DO have to say that my Begonia Grandis leaves are starting to show
signs of Fungus--or whatever---the leaves are getting spotty and look like
sections are rotting...BUT--I imagine that NO begonias like downpours
every other day, with no respite from the high temps and the Humidity
that the rains produce...
The affected plant's roots do feel and look rotted when I pulled them up.
Mushy!

I do not have chlorothalonil.
--Does it come under some Brand name in Big Box stores? I work at a HD.
How about Daconil? Been meaning to buy that anyway?
--How should i go about treating the Phytophthora crown rot.?
--Does it spread to other plants? Or--does it just stay in the area the
sick plants were?
--Do I dig up the soil around the plant's root base and discard it?
--How would I use the chlorothalonil? Soak the soil--spray all other plants?
--Is it "plant specific"? Like--ONLY petunias???
--Could I plant annual Dianthus in these spots to fill in?

Here is a picture of some of the beds--so many pretty plants in it...
These Petunias were in front...in several places.

Lots of Questions--but I thank you! Gita

Your flowers look beautiful. Great pictures!

I have heard some petunias...such as the wave petunias are more senstive to the disease. Whether the one you bought came with the disease or not is hard to know. It is a possibility.

The ones that were planted earlier were able to establish themselves under less stressful and less disease conducive environment. So that also might be a reason why you dont seem to have the disease there.

I would guess that many plant diseases are always there until the right weather and envirnomental conditions make them active and then become problematic. And each variety and each plant have differening sensitivities to disease. Even slight differences in location and microclimate can affect disease development.

Chlorothalonil is sold as ortho max garden disease control and yes they sell it at the Home Depot. http://www.homedepot.com/p/Ortho-16-oz-Concentrate-Garden-Disease-Control-0337060/100046414

A couple of applications a week apart should help stop the spread. I would remove and throw away all affected plants. Then treat remaining petunias by applying generously to the foliage and slightly drenching the soil around the base of each plant. I would also treat the soil where you removed the plants.

I'd wait a few weeks after treatment to plant the Dianthus.



This message was edited Jul 22, 2013 10:00 PM

Gita,
I think that Dr O could be right. But it looks like it doesn't matter whether it's fungus or nematode, the treatment is the same: remove the soil and plants and start over with healthy stock.

I don't have any experience with those fungicides so I can't say what to use on your remaining healthy plants. I think that the problem is that the fungicides only work when they come in contact with the fungus, and if it's a soil-borne pathogen, you're not going to be able to make contact with it using the spray....

I have no idea if I'm right. I've been wrong before. With this crazy warm/cool/wet/dry weather this year, it has been a good year to be a plant pathogen, not such a good year to be a host plant!

Dr. O--checked out your profile----you REALLY ARE a Doctor!!!

Karen--you can just click on his name and read his own profile at the bottom...

Now--a question:
I am full of them--but then--that is how one learns....a cumulative knowledge.

Karen--you said "Remove the soil"...How much of it should i remove!!!
I am willing to dig out some of the surrounding soil where these plants died in.
How much soil would be enough? Just around the roots? Gotta be reasonable here......

Dr.--(you must have a first name????) The last 2 Petunias I bought
were in 6" pots and they were "Waves"...Last chance--$1 each at the
garden center. They looked leggy (understandable) but were all in good bloom..
I planted them, as usual, just barely loosening the root ball.
When i pulled them up--DEAD--the whole root ball was still there...intact..
What was going on inside of it--I do not know...

On the single dead petunias from cell packs--the roots were barely there--
and were mushy and stringy. When you said "Crown Rot"--that is exactly what the roots looked like. The crown of the roots, where it joined the plant--was all mushy/rotten...

It makes me me less stressed out--knowing that YOU--the DR.--had the same
problems. Of course--I thought I had screwed up..somehow...(not likely....:o)
What have YOU done to the locations these were in? The soil, that is???
Or--what do YOU plan to do there?
Have you had other plants with fungus issues? Which ones?

Thank you both--and Good night! Gita

Gita,

My name is John.

Just because I am a plant doctor doesnt mean I don't have problems with plant diseases. However, I usually do have a fairly good idea though of what I am seeing or what happened. I don't like to use chemicals any more than anyone else. You never know what will happen in any given year. There is alaways something to learn no matter how much school or experience you have. This is the challenge and fun with gardening. I get all sorts of diseases...from early blight to late blight in potatoes and tomatoes, brown patch in turf, powdery mildew in squashes. I get all the same diseases as everyone else...its kind of like the rain...the weatherman gets rain at his house too.

You can remove the soil if you want...I would remove the entire original root balls and an extra inch of soil arounf them. This would help reduce the inoculum of the disease and potentially reduce future problems. Karen is right...but for me it isnt practical. I didn't remove any soil. I just removed the dead plants and wont plant anything there for a while.

Karen is also right about placement of the fungicide. Since these infections take place in the crown right at or slightly beolw the soil line, its not easy to get the fungicide where it needs to go. Also most fungicides are preventive...not curative so if the disease is already taking hold, though you dont see symptoms, you might be too late. It is best to drench each plant so the fungicide soaks into the soil around each plant...as if you were watering each one with a watering can.

No you didnt screw up. Its just the weather conditions in my opinion.

John--that's better!

Karen is a degreed Plant Biologist and works someplace around DC in a lab
that deals with all kinds of plant diseases and problems.
Please ask her--I may not have all the facts....but I know BOTH of you know
what you are talking about...

You will be an enormously great resource for us.
Please join us on the Mid Atlantic Forum--we are a very nice, active group.
We have 3 Swaps a year--we meet just to get together---plants are almost
secondary. LOTS of cumulative smarts around here!!!....

We just had a Plant swap in NJ in mid-May. Just over The Bridge..
Next one coming up will be in mid-September. Look for Threads re all this...

Now--it is really getting past my bed time.....zzzzzzz Gita

Hi Gita:
I had the same problem. Luckily for me, I just popped my petunias (beautiful, healthy, happy purple ones) out of their 3 store-bought pots into an old HUGE pot petunias had been in the year before.

They'd been beautiful for two weeks in the house in their store-bought pots, but as soon as I put them out in the outdoor pot they started shriveling up (even though I had an automatic waterer on them). So it wasn't lack of water.

The temperature here (dry wind area) hit 100 though and held for four days that way, and the wind here is heavy, so they were being hit by hot, dry wind.....I think that's what killed mine (though the rest of my garden area had no problem with it, and the Pink Skullcap Scutellaria suffrutescens, which I brought home to Washington state from Texas, didn't seem to be bothered and it was in the same pot???).....

Anyway, this will be the second year I've tried to enjoy petunias and I think I'll just give up on them, since everything else in my garden seems happy here.

Just thought I'd let you know you are not alone.

upnorth--

So--now we have to worry about the Downy Mildew on Imaptiens,
Crown rot on petunias--
and the latest one--the HVX Virus on Hostas.

http://www.hostalibrary.org/firstlook/HVX.htm

What's next? Gita



This message was edited Jul 23, 2013 4:16 PM

John--

If you are still interested in the fall Plant Swap--it will be on
Sunday,Sept. 8th at SallyG's place. She lives just S. of Baltimore
In an area called "Millersville"--which is just S. of Glen Burnie...

I live right off of I-95 Exit 67B. (White marsh Town Center (BIG Mall)
in a subdivision called Perry Hall--aka Nottingham.
Directions will be posted later...

The "Haves and wants" Thread is up and running...Take a look.
I sure hope you will come! These are very nice and social....
You DO NOT have to have plants to swap in order to attend...
Gita

http://davesgarden.com/community/forums/t/1327565/

thanks! ;)