My petunias are dying. Please help!

[Kathy27]

Hello, my name is Kathy. This year I started all my flowers from seed. Petunias, snapdragons, begonias, baby's breath, verbena, etc. Hundreds of plants. I was so excited about this year because last year was not very good. The petunias I grew are from Eden Brothers and they are gorgeous. Appleblossom pink and tons of flowers. For some reason I noticed one of my plants wilted and died. Then, the one next to it. And then, the one next to that. Spaces of my flower beds are all dying off. The plant just wilts and dies. I know that we have a lot of earwigs and slugs around our house. I just started to treat the area with Sluggo Plus and I'm hoping it helps. We have had issues with powdery mildew and fungus in the past so I use Neem oil which seems to help. I don't think it has anything to do with that though. It is just breaking my heart to watch these beautiful plants die. One after another. And now it's 100 degrees outside! (38 degrees Celsius.) After a terrible season last year. I will take any advice you got. Please help!

Kathy

 

[Kathy27]

I have heard that watering in the evening contributes to the fungus issues that I have had in the past. The ground doesn't seem dry as I have been watering it every day. They started dying before the heat wave, though. One at a time in an area that keeps growing. I am going to try to break up my watering into smaller sessions. Thank you.

 

[cpp gardener]

It is very possible you have a Phytophthora root rot issue. One day they look fine and the next you’d swear someone cut them at soil level. It is very difficult to control once it infests your soil. I use a product called Garden-Phos on mine. As a preventative it works fairly well, but if they start to wilt they’re goners. It’s safe for veggies and pets.

 

[Kathy27]

Thank you all for your help. I have been told that you should only water the roots when it is sunny and hot because the water on the leaves can literally boil killing the leaves. That is really hard to do. I got up at 7 this morning to water everything and it is already over 90 degrees. Going over 100 today. I just wanted to add that only the petunias are dying. They are planted among snapdragons, ageratum, dahlias and Lantana. Why just the petunias? I tried to be more creative with my flower beds this year and not just plant everything in a row. But soon there won't be any petunias in my front flower bed. Leaving sweeping areas bare.

 

[Kathy27]

I appreciate that, thank you. All my different flowers are doing quite well. No problems. Only my petunias are dying. They are my pride and joy but a few more die every day. I still have some carnations to put out and I think I might just fill in the open spaces out front with those. I would like to move petunias from other areas into the front, but I'm just afraid they will die too.

 

[cpp gardener]

If they’re the only ones dying, I bet it’s Phytophthora. Almost instant death to Vinca, Petunias, Calibracoa, Pansy. Once you have it, it never goes away. Use Garden-Phos preventively or choose other plants.
As for water on leaves during the day, that is an old-wives tale that has been disproven numerous times. Choose some plants you feel you can lose, or some you cherish, it doesn’t matter which and spray away one sunny June afternoon and see what happens.
NEVER use newspaper or cardboard in a garden under mulch. It impedes water penetration and gas exchange with the atmosphere. It smothers the soil biome, including worms. Lots of mulch, yes, cardboard and newspaper, NO!

 

[cpp gardener]

California is about as far west as you can get in the U.S. without a plane and our Summers are plenty hot and dry. Regardless, paper and cardboard smother life under them when covered with mulch, or anything else. Use lots and lots of mulch, but don’t put anything underneath it.

 

[Kathy27]

CPP, I think you found my problem. I have read numerous articles on Phytophthora, and that hits the nail on the head. I guess I will just dig all the soil out of my front flower bed in the fall and replace it. Maybe I can remove it with the sterilization of the area. Probably not, but I gotta try. I think I know why it happened, too. We removed and replaced the soil to improve the nutrient levels in that area. That would be why they are only dying in that area. Do you know if it kills carnations? I still have about 10 carnations to plant, and I could put them there. I'll see if I can find it online. Google knows all. Lol! I do have copper fungicide, and I will try to spray it tonight. Thanks so much. I really appreciate it.

 

[cpp gardener]

Phytophthora isn’t a big problem for carnations.

 

[Kathy27]

Thanks cpp. That's great. I suppose I know where I'll be putting those now. I sprayed everything with copper fungicide yesterday, and I was surprised how much the plants perked up. The weather here is crazy. It's never consistent. Upper 90's to low 100's this week with humidity so thick you could cut it with a knife. Sometimes when I'm working outside, I have to change my clothes multiple times because of how sweaty I get. And today it is 74. It's supposed to go back into the 90's tomorrow. The statement, "it's not the heat, it's the humidity", couldn't be more true. I hate that I have this problem, but I'm glad to know what it is. Thanks again.

 

[stephenc]

you can also try some 4 o'clock flowers as a sub for the petunia. looks almost the same, but stronger and likes the heat.