How long does it take to recover from spider mites?

[justBonsai]

My trees recently got hit with a solid spider mite infestation. Deciduous trees are pretty good. Junipers not so much. Mostly discoloration but some dieback.

Fortunately the most heavily infested tree was a small shohin shimpaku. Unfortunately it is also one of my nicer trees. I secured the soil and submerged the entire tree in a 5 gallon bucket for an hour. Spent a good time rigorously washing and cleaning the foliage while it was submerged too. It's been a day and visually I cannot see any more spider mites.

I've sprayed with neem oil and will try to have repeat applications done every 1-2 weeks. I also plan to have the foliage jet washed every few days or so to continue to dislodge any stragglers.

Assuming my plan is successful how long can I expect it to take for a tree to bounce back? The tree in question has a lot of foliage and a healthy root system. Prior to this outbreak of spider mites it was super strong. I'll add pics later.

 

[Brian Van Fleet]

Probably a year. IME, neem oil is not strong enough to eradicate spider mites, and I don't like using oils in the summer, I'd step up to malathion. Don't expect much from the junipers for the rest of the year if they were hit hard, just let them grow and recover. Plenty of foliage is required to get them strong.

I nearly lost this one to spider mites in early 2015, and it's still recovering. Healthy now, but much slower than the other shimps in the garden even this year.

 

[justBonsai]

Probably a year. IME, neem oil is not strong enough to eradicate spider mites, and I don't like using oils in the summer, I'd step up to malathion. Don't expect much from the junipers for the rest of the year if they were hit hard, just let them grow and recover. Plenty of foliage is required to get them strong.

I nearly lost this one to spider mites in early 2015, and it's still recovering. Healthy now, but much slower than the other shimps in the garden even this year.

I do have malathion on hand and will try some of that. I read somewhere that it's not effective on mites but maybe alternating treatments might be better.

I think I caught the problem before it became too bad. Definitely some yellowing characteristic of spider mites but no significant "dulling" or grey coloration. My other juniper hardly has any discoloration but some small branches were sucked dry by the pests.

I've only been growing bonsai for a bit over 3 years now but never have been hit with spider mites before.

 

[Brian Van Fleet]

Well, are you sure it's spider mites? This time of year, Shimpakus shed old interior growth.

 

[justBonsai]

Well, are you sure it's spider mites? This time of year, Shimpakus shed old interior growth.

Positive. My vision is pretty good and I could see the tiny buggers crawling over the foliage. Also the fine webbing they leave in the interior of the branching.

How often did you treat with malathion? I read that because spider mites have such short reproductive cycles improper insecticide use can create more resistant generations.

 

[Brian Van Fleet]

5-10 day intervals.

 

[chansen]

I've had good luck with pyrenthin as well. I usually rotate between chemicals and insecticidal soap, just to make sure they don't get too used to one treatment. If you really want to go all out, get sultan. It kills them at all stages, according to the label, and the other treatment options don't get the eggs. It's expensive, but you heavily dilute it.

 

[milehigh_7]

Before you treat with the chemicals, spray upwards from underneath the foliage with as high a pressure as you dare. This will physically blast them off the tree. Then treat. I have gotten away with no chemicals at all if I catch the buggers soon enough and blast them off every day for a week or so. In this case, I would just do it prior to your treatment regimen.

 

[justBonsai]

Before you treat with the chemicals, spray upwards from underneath the foliage with as high a pressure as you dare. This will physically blast them off the tree. Then treat. I have gotten away with no chemicals at all if I catch the buggers soon enough and blast them off every day for a week or so. In this case, I would just do it prior to your treatment regimen.

Yeah that's what I've done the past 2 day on all the trees and followed with neem after. I think physically I have pretty much removed most of the spider mites. I know there must be eggs so I will continue treatment and rotate between neem and malathion.

 

[milehigh_7]

Yeah that's what I've done the past 2 day on all the trees and followed with neem after. I think physically I have pretty much removed most of the spider mites. I know there must be eggs so I will continue treatment and rotate between neem and malathion.

Evil little buggers...