What’s Wrong Here? A Blog Quiz-
If you see a pine with lushly growing moss on top of the soil media, like the one below, alarm bells should be going off. As pines generally don’t like overly wet soil media, lush moss is a lucky clue to adjust your pine care. And if things are really soggy, you might even see algae and liverwort growing on the surface, so those are double alarm bells.
If you see any of these indicators of high moisture, what are the causes? There are four main ones, but you might think of others.
A lodgepole pine with lush moss, a clue something is awry…
Algae on soil surface, a worse clue
Liverwort growing in a pot, another of the bad clues
For the many benefits of moss in bonsai practice, please check out Chapter 37 of Bonsai Heresy: 56 Myths Exposed Using Science and Tradition.
Also, Jonas Dupuich has some great tips on his recent blog post on watering conifers.
Hi Michael, I have put sphagnum on newly repotted pines in the first year as the soil allows for quick drainage of the water. I don’t have it on Established pines due to staying to wet. No moss in winter. Do you do anything similar?
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Yes, I think you could apply some in the summer for the first year. I don’t apply sphagnum to pines, usually only deciduous. Eventually some live moss grows but I’m only happy if it’s struggling a bit on the pine pots. And often take some off in the winter if it’s too much.
Jeffrey Robson Here. I’ll have a go 1. Mushrooms sprouting from the soil, 2. yellow or pale needles & 3. deformed needles and soft needles (I believe 2 and 3 are both symptoms of root rot due to excess water and fungal issues as well as #4. ) and I believe 4. could be the evidence of cankers on the trunk & bark.
Sorry, I was not clear: The possible four Causes of lush moss, algae, or liverwort. (I’m going to rewrite the post…)
If you have manatee’s or brine shrimp in the container it is too wet!
Hi Michael, here in wet Vancouver B.C. I struggle with liverwort especially in shallow pots in shadier spots. The liverwort seems to love the sphagnum moss top dressing and it’s little roots adhere strongly. It is impossible to remove without taking off the grated sphagnum. Maybe I just pull off all the sphagnum and reapply new top dressing?
Yes, it is exceedingly hard to control in the landscape as well. In the pot slicing it off is the best method. And then changing the care of the plant moving forward.
I’m in Vancouver as well…Langley actually..but for years battled with many unwanted guests growing in pots…I’ve tried everything over the years and have come to the definitive conclusion that being proactive is the best defence. Every time I water my trees, or even just take the time to walk around and look closely, I inspect for anything growing I don’t want. Liverwort, Irish moss, grass even…once they settle in you’re fighting a losing battle. Take the time to stop it before it begins. For me, it’s the only thing in our soggy climate that has worked magic.
2. Not enough light
3. Type of soil causing excessive water retention
4. Inadequate drainage (could be many reasons such as excessively small holes on the bottom, roots blocking the holes, shallow pots, etc.) that exacerbates the problem.
5. High humidity
6. Too much nitrogen fertilizer
7. Inadequate uptake of water due to a poor root system or the pot being too big relative to the tree
8. Warm temperatures
I guess that can be grouped into too much water, warmth and fertilizer, and not enough light.
Hi Michael – I have an ezo spruce. Do you recommend keeping ezo on the drier side like a jbp or is it OK to keep it a bit more moist with moss?
Ya, good question. Moss is ok on Ezo spruce, they like to be about as moist as deciduous trees.