Questions: Nursery stock newly repotted Colorado

I am just getting started with bonsai here in very dry Colorado. I have brought in a bunch of inexpensive nursery stock - mostly conifers - and have repotted due to many of the specimens being rootbound. I decided to just repot everything this spring, and get those skills well-practiced (Thanks Ryan and the MiraiLive team!), and wait until roots are re-established to work on pruning. I am keeping all of these plants outside.

My questions are basic:

  1. I am finding that with the coarse bonsai soil, the water tends to drain through the pot quickly. Should I keep a tray under the pots to reduce water loss?
  2. Depending on how hot the day is, some plants are drying out within 24 hours. Should I just water daily if the soil is dry?
  3. When should I start fertilizing?

Thanks for your help.

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Yes you should be watering every day, sometimes multiple times per day. The coarse bonsai soil does drain rather freely, and this is by design (because roots need air as much as they need water). It does have the drawback of needing more frequent watering.

A tray underneath will help keep humidity around the tree, but you don’t want it to impede drainage out of the bonsai pot. In my experience, a humidity tray is a minor help, and you should still be prepared to check your trees everyday and water accordingly.

As for fertilization, as we go into summer (northern hemisphere), trees will begin the summer dormancy phase while the weather is hot. The trees will still transpire water (a lot) but won’t grow much. During that time, we don’t need to fertilize as much or at all. You probably want to wait until temperatures begin to cool down again before you start fertilizing.


nmhansen, Thanks for answering my questions.

What about coverage over the soil? Can moss be used in Colorado? You don’t see very much moss growing in Colorado generally!. Are there alternatives to moss to help prevent soil washing away during watering?

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I don’t know about colorado specifically, but yes moss will help. If nothing else, dried sphagnum moss top dressing will help with that.

See the video below on top dressing creation. Even if the native moss doesn’t grow right away (or ever) the sphagnum moss part will help with water retention and making the surface of the soil more solid.

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Yep, its pretty normal to have to water more than once per day.
I’m in a routine (unless its been heavily raining), of watering in the morning, and then again in the evening (if its still light).
As long as you are watching for signs of over wet or parched soil, you are on the right path.

For fertilizing, all through spring, skip the hottest bits of summer and then through autumn, i think, generally. though it depends on if you want fast coarse growth, or more refined shorter growth how much and how often (and size of the pot).
I think its generally best to hold off for a couple of weeks direct after a repot, though i guess that was a while ago now.

Happy growing :grinning:

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