Oils (i.e. neem) on junipers and other trees

(bflin) #1

Hello Bonsai Tonight-

I have had luck with neem oil, on may types of trees (e.g. junipers, pines, fruit trees, etc), for handling aphids mites, and some fungal issues. I typically follow package instructions, and in the warmer seasons I spray at night. Recently I’ve read several notes on junipers being sensitive to oils.


If oils might be bad, what are safer 1st line defense sprays against common pests on junipers? Recipes?

Anyone have problems with oils on junipers?


(Raymond Mack) #2

No problems with neem oil on junis or other conifers. I mix in soap. Spray and get them out of sun til fully dry. Oil is the only thing that will kill mites except expensive miticides

(Jonas Dupuich) #3

Great primer on oils - thanks for posting!

I’ve used neem oil on a wide variety of bonsai with no problems, but I’ve heard - not seen - others that have burned junipers with neem oil. The only odd effect I noticed was that it turned blue junipers like procumbens a shiny green color.

Soaps are a safe alternative to oils. Pesticides are usually safe for trees, when used correctly, but can be bad for people, bees, etc.

I’ve made notes about different pests and treatments here:

(bflin) #4

Thanks your pest compilation is great. The unce article echos your observation of neem removing blue hues. interesting…

(Paul) #5

Having good luck using fish and seaweed fertilizer as a foliage feed and it seems to work well keeping insect under control. It could be that there are oils in the fertilizer that coat the skin of insect that breath thru their skin. Since I am on the east coast Neptune’s Harvest is my choice. There must be fish and seaweed fertilizers on the west coast and around the great lakes that would work as well.

(bflin) #6

Hey Paul, that is very interesting. I’m curious when you say “insect under control”, does that mean as compared to before you started foliar spray, or simply you’ve never had problem with insects before? When I use fish emulsion, I dump over the foliage, but intended for the soil, so I never see much “residue” from the fats. In your case do you spray with instructions on bottle or at higher concentrations? Very interesting insight, id like to look into more. Thanks.

(Paul) #7

Yes. About 3 or 4 years ago I questioned one of people at the University of Idaho’s seedling program about foliage feeding with fish fertilizer and was told it works and it would also help with insect control. Before that time I used neem oil and still have some left over and keep it just in case but have not had to used any. One of the nursery near me has an overhead sprinkler system for watering plants, trees and bushes and they infuse it with fish fertilizer. I really don’t know if they use it for insect control or just as a fertilizer.