I titled this months article “Summer Finale” because for many people here in the U.S. and especially those in the northern states, summer is just about over. For those of us in the south, it won’t be long for us either.
With that in mind, maybe this would be a good time to reflect back a few months to both Spring and Summer. Remember how nice your trees looked right after the leaves opened. everything looked so good and so green, and you said to yourself, “this year I’m going to do whatever it takes to keep everything looking this good no matter what”.
You made sure your trees were always watered whenever they even showed a hint of dryness, and no one had to remind you about fertilizing them that’s for sure.
But then the summer months started rolling in, and with them came the heat, and for some, like us here in the Lone Star State, that heat was relentless and seemed to drag on forever. Summer heat is not only bad for humans as it taxes their body to extremes, but is just as bad for plants, because it puts stress on them to dangerous levels also. Just because you water your trees two or three times a day, doesn’t necessarily mean all is well.
As the heat begins to take its toll, your trees become susceptible to stress, and when that happens, insects,especially the kind you really can’t see, will start to wear your trees down even more. All of a sudden your trees are looking just the way you hoped they wouldn’t, leaves turning yellow, and some even browning out, and because they are mixed in with the many green leaves that are still holding on, you just hope for the best and pray that things will turn around soon enough. You think that maybe you over watered, so you cut back a bit on your watering, but the problem persists.
The insects that are almost microscopic are usually the ones that will cause you the most problems, mainly because it’s “out of sight, out of mind”.
One thing that every bonsai owner should develop a mindset for, is Preventive Maintenance. Just as you should be going to see a Dr. on an annual basis to try and stop something before it becomes life threatening, so should you be trying to prevent life threatening or even minor damage to your bonsai.
Everyone I’m sure would like their trees to look in the best of health all year long, and even minor yellowing can take away that possibility.
Aphids are just one of the very hard to see pests that can play havoc with your trees. Spider mites and Scale are another of the very hard to see also.
Some scale is microscopic and so camouflaged on some trees, that the damage isn’t apparent until it’s too late causing major damage to tree limbs. One of the things to counter an attack of scale, is horticultural oil, because the oil will smother the scale and cause them to die. But using this product in the summer could be dangerous for your trees as they might not be able to transpire as well as they should causing just as big a problem or even worse than the first. Even a summer type horticultural oil might cause problems.
For me, I found that Neem Oil, which is an organic product, works very well for scale on my ch. elms, and with no side effects. Any type of oil should be used with caution though in the summer.
Some problems as with aphids, will show signs that are quite apparent that something is not right. One of these signs is ants. If you notice ants traveling up and down some of your trees, it’s not an ant problem, but most likely an aphid problem, because the ants are harvesting the aphids. In the pictures below, notice the dead aphids on the leaves and even on the wire, after being sprayed with an insecticide.