Horticultural or neem oil and Passiflora - Orchid Board

estación seca · #1 02-28-2021, 12:28 PM

Has anybody used horticultural oil or neem oil on Passiflora species? I can't find online whether it is safe for this kind of plant, and product labels don't mention Passiflora.

Mr.Fakename · #2 02-28-2021, 01:04 PM

What's your issue? Local nursery has a collection of Passiflora, I could ask for you.

estación seca · #3 02-28-2021, 02:22 PM

Thank you. Florida wax scale on a Passiflora quadrangularis, one of the largest-leaved plants of that genus. I don't want to use a systemic insecticide because I'd like to eat fruit from it eventually.

This plant (and a few others) arrived last fall from a reputable nursery in Louisiana. They had no pests I saw. The Passiflora has grown rampantly as I wrap it around a tomato cage in a large nursery pot. Now, months later, this scale I've never seen before appeared suddenly on a few of the plants from that shipment. The shrubby plants have several to a dozen adults on the stems. The Passiflora has only a few adults on the stem, but hundreds of tiny juveniles along the veins of about a dozen leaves.

Fortunately it doesn't seem to affect orchids, and isn't on every plant from that shipment. I haven't found the scale on other tropicals I have in my sunroom.

I sprayed the Passiflora with 70% alcohol and removed all the adults I could find. I rubbed the juveniles on the leaves when they were wet with alcohol, but I may have missed some. I've sprayed the other plants affected with neem oil. But they're shrubs with sturdy leaves, not the filmy Passiflora leaves. That is why I want to use neem oil or horticultural oil if it will not harm the plant.

Mr.Fakename · #4 02-28-2021, 02:45 PM

Dully noted. I'll give them a call tomorrow, I'll keep you updated.

Mr.Fakename · #5 03-01-2021, 08:44 AM

So, they said they rely principally on predatory mites and ladybugs when they need to kill scales/insects.

Another solution is "black soap" (Bidon 5L savon noir liquide a l'huile d'olive - sorry it's in French) which is made from linseed oil, olive oil, salt and potassium hydroxide.
When diluted with warm water, it's super effective at killing and repelling pests.

I'm not sure if you have an equivalent product in the US, but it's oil-based and tried-and-tested on Passiflora, I hope it's somehow helpful to you.

estación seca · #6 03-01-2021, 03:38 PM

Thank you. We do have insecticidal soaps. Je parles internet translation.

kg5 · #7 03-21-2021, 10:11 PM

Hi estación seca

Long time since have looked at neem oil. It was back in the early 90's.

Big stand out is neem oil is used as a contraception medication in India for centuries. Neem oil is more than horticultural insecticide. It was a new product back in the early 90's with lots of new issues to be sorted concerning treated by this oil.

Your scale must of been doormat in the soil mixture incomeing.

Doing a search surprisingly shows very little about this product. When it had so much potential back when I had contact buying weed, pests & diseases spraying poison's for the city council that I was a multidiscipline horticulturist supervisor for around 120 people.

Search says, no more than we already know. eg "Regardless of the type of plant being treated, neem oil can damage plants by burning their foliage. Do not use on recent transplants or otherwise stressed plants. Though plants must be completely covered with neem oil for the pesticide to be effective, it is a good idea to test the product on a small area first."

Am very interested. Had totally forgot about neem oil as am concerned about using insecticides to kill ants that are nesting in my Tillandsia & Platycerium clumps etc that could past-on the poison, to a plant buyer.

estación seca · #8 03-22-2021, 02:23 PM

Thanks. When I found the bugs I sprayed with 70% isopropyl alcohol then isolated it. No bugs seen since then. I'm going to wait to spray with oil until I see more bugs.

kg5 · #9 03-22-2021, 08:35 PM

In the past have used fingers and mentholated spirits to good affect. Have watched the ants carry the scale & mealy bugs from their nests up into the trees so they can harvest the execration from the scale & mealy bugs. It is a very communal happening. Amazing to watch.

Fuerte Rav · #10 06-07-2021, 07:32 PM

Hi
Still 'Neem' but off of the original tack of this thread - hope that's OK?

I gave all my Phals their monthly shower of Neem and Hort soap today, no problem there BUT I forgot that I had a tray of rooted Milkweed cuttings that I had just potted up nearby. Now Neem and Monarch caterpillars don't mix well and I'm sure these young plants will have caught some spray/drift. Has anyone any idea how long the Neem will stay active in the Milkweed plants? I've put netting over these milkweeds for the time being to stop the butterflies laying eggs on them but I'm going to have to construct a cage with fine mesh that caterpillars can't get in through from other parts of the garden as well.

It's actually been quite a good learning point. I was going to put the milkweeds in a border amongst some hibiscus but I have to spray the hibiscus with Neem or a chemical pesticide 3 or 4 times a year against cochineal so I need to think again about where I plant them!

Any advice about longevity of Neem gratefully received!