This has been a tough year in my bonsai adventure. Towards the end of last year, I felt like I was starting to get to a point where I was comfortably competent in my skillset. Repotting has become second-nature, I’ve mostly memorized seasonal maintenance timings, my wiring is where I wanted it to be, and I’ve learned more about fungicides and pesticides.
This final point is where I think I got a bit over-confident possibly. I’ve watched countless hours of Ryan Neil and Bjorn. They give pretty specific advice on pest control, so I thought I had it figured out.
This spring, I dug a couple of massive yews, and pretty quickly, they developed a massive scale infection.
I have a story about pesticides, but I’m going to redact chemical names because I don’t want anyone to make the same (mistake?) that I made. Systemics are pesticides which stay in a tree’s system for a fairly long time, and continue to be active. Contact pesticides kill on contact only. Some are designed to stay on plant surfaces for slightly longer (up to a few days), but they essentially only kill at the time of treatment.
I treated the scale with “Systemic 1” and “Contact 1” pesticides. I read all of the instructions, mixed it properly, put on protective gear, and sprayed with the proper nozzle.
When I came back the next day, I still had some scale, so I decided to wait a couple of days and then treat again with “Contact 1”. I also figured that while I was at it, I would treat all of my trees with both chemicals. This should give me a few months of no pests.
When I came back, the solution worked wonders. No scale. Well.. a handful of stragglers, but I jabbed them with bonsai wire and they were done fore. There also seemed to be no harm to any of the trees, so that was exciting as well.
About a week later, I noticed that one of my pines was in bad shape. Needles were spotted and “leaking”, and there was an almost dusty-look to the foliage. I did some digging, and found that it was most likely mites. I took a look around the garden and realized that a lot of my trees were looking “dull”. They just didn’t have the same shiny, lush verdant green to them.
Upon closer inspection, I noticed little strings of web-like substance on quite a few of my trees. I looked these things up, and it was clear that I had mites. The major problem with mites is that by the time they start leaving clear signs of their existence, they are already at population levels which can cause problems.
I immediately started to dig into solutions. I also segregated the trees which had more signs of mites. I found two major solutions to the problem. The first one is to just blast the foliage with water every day. The second was another chemical, “Contact Miticide 1”.
I treated my trees with this new chemical before bed, and quite literally had nightmares about waking up to an explosion of mite population with webs everywhere and dying trees.
When I woke up, half of my nightmare was true. There were webs EVERYWHERE. There were webs between my trees. There were webs from my trees to the ground. There were webs from my trees to the dog’s run. The sight made me sick to my stomach. I blasted the foliage of all of my trees with water before going to work, and was feeling pretty defeated.
That day I ended up Googling more solutions to mites, and came up with ANOTHER chemical “Systemic Miticide 1”. Systemic miticides are extremely rare (it may be the only one?). I ended up purchasing this chemical that day. $225 for a tiny bottle. Luckily it’s so concentrated that it should last me a couple of centuries.
After making this quite un-fun purchase, I drove home and expected to find a warzone in my trees. I was expecting the absolute worst. What I found was…nothing. No new signs of mites. I went to bed, got up the next morning, and again, no mites. I kept checking my trees a few times per day. No mites..
I still have no idea what that morning of apocalyptic webs was. Were the mites abandoning their newly poisoned tree ships? I just don’t know. It’s now been a few weeks and I have no signs of a mite infestation anymore. My trees are starting to green up significantly, are slowly taking up more water, and just look healthier.
After and during this fiasco I spoke to quite a few people about their pest routines, and most people said they do nothing, and don’t use any systemics. I thought I was being proactive, but I’m almost certain that I caused more problems than I would have had if I only treated the specific trees which were affected by the scale in the first place.
I’ve learned a lot about pesticides and pests through this process, so I’ll take it as a learning opportunity. I’ve learned about groups of pesticides, how to rotate pesticides, generational immunity in pests, different actions of pesticides, and most importantly that there is no “ultimate” pesticide. They are all going to leave some pests, and if you manage to kill all of their predators off with a specific pesticide, you run the risk of creating a massive boom in population.
From here, I feel like there are two solutions going forward: Take the “do nothing” approach. Or use the “Systemic 1” for everything other than mites, and also add the “Systemic Miticide 1” to that routine. I’ll be honest, I just don’t know..
After some brief chat about soil PH in our club, PH is going to be my next adventure.