Dear all,

It's summer in Sydney. My balcony is being eaten out by the insects there. I tried some general pesticides and fungicides but they are not quite effective. The green worm is found on my plants everyday. The rusts are never gone. There are a lot marks appearing on quite pest-resistant plants as well. Is there anyone who could tell me how to get rid of them? At least the green worms. They are huge, fat and gross...

Worm-phobia,

Kate

I don't know about the other plants but I think the rose looks dry. The green worms are rose slugs (sawfly larva) and they are a real pest. There are sprays for them but I have no idea what might be available in Australia. I will say that we don't usually recommend those combo sprays as they are never full strength and tend to not be as effective. The only other method is to hand pick them off. That is tedious but very effective. There are also fungal sprays that will take care of rust but again I'm not familiar with brands in Australia. Make sure you find one that says specifically for rust. It will protect new growth and any leaves not infected yet but any existing rust infection on leaves will remain. Most fungicides are a preventive NOT a cure.

A good rule of thumb is to only spray for insects when you see them and have properly identified them using the appropriate spray for that insect. For diseases you can spray BEFORE you see symptoms to prevent an outbreak.

seilMI said:I don't know about the other plants but I think the rose looks dry. The green worms are rose slugs (sawfly larva) and they are a real pest. There are sprays for them but I have no idea what might be available in Australia. I will say that we don't usually recommend those combo sprays as they are never full strength and tend to not be as effective. The only other method is to hand pick them off. That is tedious but very effective. There are also fungal sprays that will take care of rust but again I'm not familiar with brands in Australia. Make sure you find one that says specifically for rust. It will protect new growth and any leaves not infected yet but any existing rust infection on leaves will remain. Most fungicides are a preventive NOT a cure.

A good rule of thumb is to only spray for insects when you see them and have properly identified them using the appropriate spray for that insect. For diseases you can spray BEFORE you see symptoms to prevent an outbreak.

Thank you so much for your advice. I hope other special pesticides will work. And you are right, that rose is dry. In summer， it could be more than 40 degrees in the balcony.

Basically I agree with everything Seil said. However, if it was my house, my balcony, I would not use any kind of insecticide or fungicide ; I don't use them out in my garden, so figure if I'd want these poisons right outside my door on my balcony! There are much safer and effective alternatives. Number one is try to improve your general culture of the plants-a lot of water, even provide some shade ; roses hate that kind of heat. If this interests you I'll try to get back with more ideas, but am in a hurry just now. Good luck!

bart2018 said:Basically I agree with everything Seil said. However, if it was my house, my balcony, I would not use any kind of insecticide or fungicide ; I don't use them out in my garden, so figure if I'd want these poisons right outside my door on my balcony! There are much safer and effective alternatives. Number one is try to improve your general culture of the plants-a lot of water, even provide some shade ; roses hate that kind of heat. If this interests you I'll try to get back with more ideas, but am in a hurry just now. Good luck!

It would be better if the problem could be solved without any pesticides or fungicides. May I seek you advice about that?


The extreme heat is only occasional.
Normally the temperature is between 25 and 35 degrees if the global warming is not getting worse.
LOL~

To start with, I'm posting this link to a short article that I found on Internet about natural fungicides and insecticides.
https://homeguides.sfgate.com/...

I encourage you to do your own research on this topic however; there are several different " recipes " for these home-made , natural fungicides. For example, there is one made with water and skim milk, too. Also, the article doesn't caution enough about avoiding the use of oils when the sun is out and the temperature is high,so again I advise to to do some Google-ing on the topic. Likewise with the ideas about companion plants that help repel insects -supposedly pink geraniums are a big help. for example ,but I've heard of others. I did not know that borage was so good until I saw this article, nor that garlic helps ,not only by it's smell, but by adding sulphur to the soil,so that just goes to show how helpful it can be to hunt around a bit on Internet and read up on a matter that is of interest.Also, this article doesn't mention one of the easiest and best natural insecticides-soapy water spray. But. again, look it up to find the recommended dosage, and, as always when spraying ,don't do it when the sun is out.
The thing is that even 25 degrees is quite warm for roses, and the fact that they are in pots on a balcony is going to increase the plants' subjective experience of heat-by this I mean that,on a balcony, the light and heat are reflecting from the paved surfaces, whereas in the ground, surrounded by grass, plants are going to "feel" cooler. So they will need a lot of water, and might prefer some shade as well. Good cultivation is the most important thing to help control insects and disease.

Like Bart, I wouldn't want fungicides (not to mention insecticides) right outside my window or door. Remember that ". . . cide" means that it kills something.

Decades ago, when a dog we loved began to seizure everytime we sprayed, we re-assessed our priorities. We decided that roses which rusted or mildewed to an unacceptable level without spray weren't going to work for us. So . . .

If it rusts, it goes. We look for cultivars that are resistant to fungus diseases. Without sprays, we have fewer harmful insects, rather than more.