Dianthus are dying, fungus or heat? Please help!

This is my 1st garden in our new home. I was so proud of all my hard work. Everything was thriving! I deadheaded my flowers 2 times a week and they had so many blooms that they were just beautiful!
The heat came, then my Dianthus stopped producing. Someone told me to trim the tops of the stems and they would produce more. I did this and now 2 weeks later, they are all turning yellow and dying.

I've tried....
Loosing the soil to get more air, watering more, taking off the dying leaves,

Not sure if my trimming did this..the heat is doing this..or is this a fungus? Please help!

I'm including a picture so you can see what they are doing :o(

My one plant did the same thing. It isn't well established and I figured it was the heat.

Dianthus don't like a lot of water and so while important to have a nice rich soil - it must drain well. If you are giving extra water -- make sure draining and don't overwater.

The drainage is good. The beds are new and I didn't have any problems until the high temps came. The only reason I'm giving extra water is the temps here in GA have been over 90 degrees for the past 2 weeks. Today it is 95!
I'm sure I'm not overwatering..as I check the soil for moistness before I water. And I always water in the morning to avoid getting a fungus.

I wish I knew what was causing this as the plants were beautiful before they started dying :o)

They could just be suffering a bit from the heat--especially if they were newly planted this year they will need some extra water, etc. The other possibility is that they may need a little less sun than they're getting--when you live in a climate with hot summers sometimes things can't handle quite as much sun as the plant tag would lead you to believe. Something where the tag says full sun might be happier if it gets a little shade during the hot afternoon, etc. I don't know if that's the case with Dianthus or not--I don't grow too many of them and the ones I do have are not in full sun.

Also, even though it'll look a little ugly, you might consider leaving the dying leaves in place--if you're going to continue to have hot weather they can help provide shade for the leaves underneath and could help prevent the problem from continuing to get worse. Otherwise every time you cut off dead leaves, you're exposing new leaves to the sun and then they burn and you end up cutting them off, etc.

It looks like heat has hit it. I would only water when needed. My dianthus looked cruddy the first year and died out in a couple spots, but it did come back the following year with alittle more gusto. This year, it came back beautifully. If your plant is newer, just water as needed and let it be for now. Heat and being newer (if it is) will take a toll on it. If you do not see any new growth and it does look pretty dead ...then you may want to give it another go with a new plant in the fall time so it can establish roots before winter. So when Spring rolls back around, you will have a plant ready to bloom for ya... :) Fall may be a better time for planting in your area because the roots will establish and not be blasted with heat/humidity like I have in my area.

This message was edited Jul 23, 2010 12:59 AM

I'll add that your Dianthus looks like one of the D. chinensis hybrids that are used like pansies as spring and fall bedding plants in the south. If this is the case, they don't love the heat and they look pretty typical (if anything, better than typical). If they make it through the heat they'll look good again and bloom again in fall. If not, you may want to consider replacing them with on of the more heat tolerant D. gratianopolitanus cultivars.

I agree with plantfreak, I have the same type of Dianthus as yours and mine have pretty much quit producing flowers, too. They can't take the heat at this time of year. If they've been healthy so far, keep watering them like you have been to encourage root growth; they should bloom again in the fall when temps are cooler if they survive the summer heat.

thanks everyone! I am beginning to think it is the heat also. Just to be safe I purchased something that kills bugs and funguses. I have sprayed them just "in case"..
I so loved these flowers as they were just beautiful! Next year I think I'll find a part shady spot and try again :o)..
It's so nice to have a place to go to where you can ask questions and learn. For a new gardener like me the resources on this site are so needed!

Happy Planting!

My "Super Raspberry Parfait" Dianthus did the very same thing in mid/late May, down here in the tropics, after blooming so nicely all winter & early spring. At the end of May, during one of my lazy moments, I whacked them down to the ground, instead of just pulling them out. A couple of weeks later I noticed the plants all reappearing with 100% new growth. They're just starting to rebloom again with lots of new buds. Here's what they are looking like today. If this strategy worked in the heat of South Florida it may very well work in Georgia also.

Jon

Barb, fyi spraying plants "just in case" can often make symptoms like that worse and is usually not the best practice. In this situation, it would be like you taking antibiotics to cure sunburn and heat stroke. Not helpful, right?

Hi Barb, just wanted to let you know that my dianthus do exactly the same thing once we hit the hottest part of the summer. I'm not sure it's the right thing to do, but when that happens, I sheer them back hard. They seem to like that, and they do look nice again once the temperatures go back down. Some of them even bloom again before winter.

Barb, there are so many varieties of dianthus available today, Some are more heat tolerant than others. I have some that bloom all summer, but they only get morning sun....other die back in summer and bloom again in the fall and some are annuals that only hang around til the temps get high. Here are a couple links for you.

http://www.thegardenhelper.com/dianthus.html

http://oldfashionedliving.com/dianthus.html

Hi I was hoping someone could tell me if the Dianthus I planted in my flower box this Spring is an annual or perennial? Also, will it flower through Summer? Or should I move it to a bed after the blooms fade? It is my only window box, so I'd definitely like to keep color all Summer. I'm in zone 7b.
Thanks

Ali hoke, this thread was from 2010, start a new thread so folks can see it, plz. Dianthus can be deadheaded and blooms will return