Bonsai Tonight

An educational website about bonsai development

Drench for root aphids follow-up 1

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Back in July I treated a number of black and red pines for suspected root aphids (see “Why are my trees yellow“). I’ve noticed a few changes since then and wanted to share what I’ve seen.

  • Some yellow growth has turned green
  • The healthiest trees are sending out summer shoots
  • The weakest trees remain unchanged

My biggest worry when drenching the two- and three-year old pines was that the treatments would damage roots. Although it’s far too early to tell, I can report that there has been no evidence to suggest catastrophic changes to the trees that were treated. On a more positive note, I’ve noticed a few trees turn from yellow to green. The new needles on the pine below were yellow before treatment. Although the old needles remain yellowish, the new needles have greened up considerably.

Black pine

3-1/2 year-old black pine

Black pine

Spring growth

I have no way to tell whether or not the greening resulted from any treatment, but I’m happy nonetheless as it’s a sign of the tree’s health.

Some of the healthiest trees are now sending out summer shoots.

Black pine

Summer shoots on 2-1/2 year-old black pine

Black pine

Summer shoots

We often think of black and red pines as trees that send out new growth one time per year – two when we decandle – but healthy pines regularly send out summer shoots when they’re growing vigorously. This is particularly true of younger pines.

Black pine

1-1/2 year-old black pine

Black pine

Summer shoots

Red pine

1-1/2 year-old red pine with summer shoots

Pulling a flat out at random, I noticed that all but one of the trees had summer shoots.

Black pine

1-1/2 year-old pines

These trees will all need wiring and repotting before next spring. In the meantime, I’ll continue to feed heavily to help the trees prepare for winter.

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Comments

  2. Jonas, I read your first article on root aphids, but wanted to ask for your thoughts regarding the topsoil on my JRP. I tree is doing great, very green and lots of new growth. When I was rotating the fertilizer bags this week, I noticed what looks like white bacteria / fungus. It is only under the bags and I am hoping it is the good stuff we look for in our bonsai soil. Again, there is no yellowing and the tree is growing amd looks very healthy. Good fungus / bacteria, aphids or what?

  3. Hi Thom – I’d guess the good stuff, but it’s hard to tell without a pic. Feel free to post a pic and let us know what fertilizer you use at ask.bonsaitonight.com.

  5. Hi Ray – it’s too soon to tell. I’ll have a better idea around repotting time based on root health and the real test will be how well the trees come out next spring.

  6. Did you dunk the trees each for two minutes in the different solutions? Or some solutions you let them sit longer, or less?

  7. Thanks, any solution appear to be more effective than the others at this point on the ones you have treated?

  8. Not at this point – I don’t expect to know how the treatments worked for the aphids until I repot and get a closer look at the roots. I plan to follow up again towards the end of this year or early next year.