Do I have a pest problem?

[RomanW]

Hi I'm growing two superpetunias "Beautical" in pots on a terrace beneath a balcony. I noticed they have some small black grains on stems, and leaves seem to be eaten by somethng (see photos). The weather was quite rainy and cloudy, so they didn't get much sun recently. What should I do? Thanks

 

[pepper]

That black stuff is poo, probably little green caterpillars but that's a guess. You should look closely around and under the leaves to find what it is then post a pic of it.

 

[pepper]

And welcome to the forum

 

[RomanW]

I couldn't find anything under the leaves, maybe because it's dark, I'll try tomorrow but something is eating the leaves.

 

[pepper]

They will probably be hard to see, they are good at blending in if it is green caterpillars. But yes, the leaves are getting eaten.

 

[RomanW]

What do I do?

 

[pepper]

What do I do?

You could spray it with an insecticidal soap, that should work. I personally wouldn't use anything on it, I would get a sheet of white paper and gently fluff the plant to see what falls out of it, and go over it leaf by leaf picking off the caterpillars.. but I know I'm weird lol. Most people would just spray it with some poison.

 

[RomanW]

I'm keen to avoid using poisons, especially that my cat walks around the terrace (or some neighbours' cat might). I'll give your advice a go, hope it will save them Thanks.

 

[pepper]

I'm keen to avoid using poisons, especially that my cat walks around the terrace (or some neighbours' cat might). I'll give your advice a go, hope it will save them Thanks.

No problem let us know what you find. There is probably some safe for pets soap stuff you can get but I don't know for sure, and I don't know how well it would work. There is different homemade recipes on Google using oil and dish soap but I don't see that being good for the plant. Once you see one and know what to look for it will be easy to find them.

 

[pepper]

Just to mention it doesn't at all look like slug droppings but there are some leaves that have holes in them that could be from slugs so if you can check it at night or very early in the morning just to rule them out. If there are slugs a little beer in a cup will help get rid of them.

 

[RomanW]

Today morning I shook the bushes a bit and found 3 caterpillars (2 big, 1 small) on one bush and another big one on another bush. Is that the expected number? How many are usually to be found on a single petunia bush?

And how do you use this beer? Sprinkle it on the leaves?

 

[pepper]

Today morning I shook the bushes a bit and found 3 caterpillars (2 big, 1 small) on one bush and another big one on another bush. Is that the expected number? How many are usually to be found on a single petunia bush?

And how do you use this beer? Sprinkle it on the leaves?

I don't suppose you took a pic of them did you? Without seeing them I don't know what kind they are so I can't say how many there would be. Some moths lay a single egg, some lay many so it depends on what they are. But there is probably more. I will look into some natural pet safe insecticide soap and let you know in a bit what I find. It might be the best method for you.

The beer you don't put on the plant you just put it under it in a dish or something to hold an inch or two of it and the slugs drink it and drowned. But I wouldn't worry about that at this point, I'm pretty sure it's just a caterpillar problem now that you found some but didn't see any slugs.

 

[RomanW]

Thanks

 

[pepper]

So, some insecticidal soap kills caterpillars and some doesn't. It is pet safe but keep kitty inside when you spray it on so not to inhale the mist. I don't know what kinds you have where you are so you would have to read the labels to make sure they kill caterpillars but Safer's apparently works on them.

Another option that apparently works is 2tbs of vinegar to 4 Lts of water sprayed on.

Neem oil is a popular option but I have heard lots of horror stories about it hurting the plant worse then the pest did.

I've never tried any of these so I am only going by hear-say and google. But I would use the neem oil as a last option.

 

[RomanW]

Thanks! I suppose vinegar is easiest.