Sunflower Oil

Johnjoe · June 2023

I've just recently used Sunflower Oil spray ( One-Cal, so they'll not die of obesity!) on my Lily to get rid of Lily Beetle grubs and its worked a treat after 24 hours and a quick hose down. Do you think it would be ok for mild infestations of greenfly on Roses?

Johnjoe · June 2023

In the green bud stage, not open flowers?

punkdoc · June 2023

I don't think you need the oil, just a jet of water will do the job for greenfly.

nick615 · June 2023

..... or you can use the cooled liquid from boiled rhubarb leaves for aphids in general.

Dovefromabove · June 2023

I agree with Punkdoc 👍

Fairygirl · June 2023

Also - don't assume there aren't any more lily beetles doing their thing. I'm not sure of the effects of that oil on the plants long term either. Is there reliable info about it?

I also agree, a skoosh of water is all that's needed if there aren't any predators eating the aphids.

Pete.8 · June 2023

The problem with using oil on plants is that they'll likely bung-up the plants stomata (sort-of like our lungs). This prevents the plant from transpiring (breathing) properly which can then lead to further problems.
The only oil I'm aware of that keeps this to a minimum is neem oil - but I've never used it.

I've given up with my pot of lilies that I've had for years.
No matter how often I search for the little bu**ers they shred the plants in no time.

Lyn · June 2023

Best to check under the leaves and get the eggs or grubs in the first place, the beetles tend to drop off and turn upside down, it would be difficult to know if they’re dead or just hiding.

Johnjoe · June 2023

Thanks, all points taken on board! I see this morning there are a few lily beetle grubs that have escaped my oily wrath, so will do the hand-picking off, yuck!

bédé · June 2023

Vegetable oil is an effective way to kill inects. I use cheapest, usually rapeseed. I emulsify it in water with a touch of washing up liquid. The emulsion is more sprayable than neat oil.

The washing up liquid as a dilute solution is also a good contact insecticide by a similar mechanism.

My actual technique is to get in early at the beetle stage. I do a small hand spray of the beetle, that freezes them and stops then dropping off. I then chop off their heads with my thumbnail.

I usually get few grubs. Those I do, T reemove complete with the leaf.

Fairygirl · June 2023

You'll have to be vigilant for a long time with lily beetles @Johnjoe. They're very persistent. Cleaning off the grubs and their excrement is an ongoing bit of the process too. All part of the fun

That was my worry @Pete.8, re using oil. I couldn't see how that could be a good idea, and I wondered if transpiration would be the main problem. It's easy to forget how important that is for plants.
We never used to get lily beetles in any great quantities, but they seem to be surviving far more easily nowadays. I can understand why you've given up on growing them though, which is a shame. Too much hassle. I'm getting quite good at catching the adults and squishing them, but you have to keep on top of the all the rest of it with the grubs.

Sunflower Oil

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