Dianthus: bacterial wilt, virus or something else?

Hi, I've been lurking here for a few months now and I guess it's time to post a question.

I have a balcony garden in Mediterranean zone 9. I had two different coloured dianthus in a pot. They had finished blooming and were deadheaded. When they started flowering again a few weeks later, I noticed that the red ones seemed to be having problems that didn't affect the pink ones. They were not as tall, the blooms looked wilted and faded as soon as they opened and had no smell, the stems were weak--in fact, some of the blooms were coming right out of the ground with no stems to speak of. They definitely looked diseased.

I noticed that some leaves seem to have white squiggles on them, as if someone had dipped a pen in bleach and then doodled on them. This was more apparent on the underside, though still visible from the top.

I also found some round balls in the soil that were about 1/2 cm in size, a yellow-green colour and were easily crushed between the fingers. They were white inside. I seemed to recall seeing these same things years ago in a houseplant that wasn't doing well and I really have no idea what they are, though I suspect some sort of crustacean.

In the meantime, I've separated the two plants as best I could, to see if the pink ones manage to survive.

Any help appreciated.

Lana

Lana:

With the information given, I can only attempt some fairly general advice. Whlle Dianthus species can suffer from fungal, bacterial, and viral diseases, let's take a different approach.

First, the second bloom phase of many plants is often weaker with smaller blooms. One of your plants may be stronger than the other, is all. Your plants may simply be fading out for the season in their own way and time. There are many species of Dianthus and I can't offer advice about how to treat yours during their down time, if in fact you can carry them over.

As far as the squiggles go, it sounds like leaf miners have affected your plants. These are various species of tiny flying insects that deposit their eggs in leaves; the larvae eat a path between the top and bottom layers. The usual advice is that there's not much you can do about these, except to remove affected leaves as soon as you notice them. Normally leaf miner activity doesn't affect the health of the plants overall, but can be an aesthetic problem. (Often, leaves will grow back and when leaf miner activity is over for the season, you won't see any more damage.)

If the plants are still in the soil mix they were grown in (or have some of it still around their roots), the odd little balls you found in the soil could be fertilizer pellets that growers will mix into the growing medium. Some dissolve more slowly than others, and one always finds a few left over in the soil. If that's what it is, no problem there.

So.....in the absence of more details.....I think it may very well be that your plants aren't suffering any dire diseases other than seasonal age. If it is disease, it doesn't seem that you'd be able to do much at this time other than dispose of the plants and the soil in which they're growing. (And of course treat yourself to some new and different plants for your balcony!)

Best, Tyra nNJ usa