Why we shouldn’t grow trees under trees…

Generally speaking, mushrooms grow better under trees than trees do. When talking about bonsai, there are a number of reasons not to grow them underneath larger trees. To take just one, there is usually not enough light. The following photo illustrates this poignantly…

tree under tree

This is on my morning walk. Three small pines were planted under a large spruce. The one on the left is getting the bare minimum light to be healthy. The one in the middle isn’t getting enough, so it is weak and leggy. The one on the right, in deepest shade and fully under the canopy of the spruce, is dead.

Conifers in particular need a LOT of sun. But even a deciduous tree would be weak if grown under the canopy of the spruce in the photo.

Keep your bonsai in the sun! And then water them.

9 Comments

  1. Its not a tree, however, I wonder where you fall on the matter of shade cloth? At 6500′ we have some intense sun and I put my trees under 50% shade cloth to keep them from overheating and to protect them from hail (which is way more present than I’d like). I did notice my trees tend to grow maybe slightly larger leaves (I’m talking of my japanese quince here) but I may only THINK they are growing larger leaves because this year they actually HAVE leaves (I didn’t have hail protection last year). Either way, the foliage looks 10 times better than if I were to put them in full sun. The only trees that don’t get put under the cloth are my olive trees (euro olives). They seem to do just fine even with the hail.

    • crataegus says:

      Yes, good point, technically not a tree. I tend to use ‘tree’ somewhat indiscriminately, and should have said ‘bonsai under trees’. The pines in the photo are shrubs, yet have the same light requirements as full size trees.

      Shadecloth: Good protection from hail. Try to keep as low a percentage as possible while still providing protection. If you can do 20-30% that would be better for the trees. All you need to do is take the edge off, and keep the ambient temperature down. Too much shade, above 55%, and we can really mostly only grow shade loving plants.

      I used 55% in Arizona when I lived at 4,500 ft. and it worked, although my conifers were on the outskirts and got more sun.

      Slightly larger leaves might be seen, yes. But it’s good to take the edge off, a good tradeoff.

      • Ah ok…well I figured the 50% was pushing it but at 6500′ it’s still pretty strong sun. I think I will push the pines to the eastern edges so they can enjoy the sun a bit more. Thank you!

  2. Alan Jabs says:

    Here in Adelaide South Australia we get temps maxing out at around 48c in summer which can last a day or a week. I place my trees under shade at these times to protec6t them mostly from drying out and burning. I currently use a green cloth but am planning to move to a white version. The green does make the trees produce larger leaves where the white seems not to. I must add I also have a fogging system that gets turned on on days where the temp is above say 36c as it drops the temp significantly and adds to the humidity. (I also have a weeping Mulberry that I place smaller trees under on these hot days with littel problems other than actually having to go and move the trees around. My Olives do stay out in the sun longer than all others but even at 48c they also come into the shade for a few days. Prevention is better thann starting again.

    • crataegus says:

      For short periods, yes, putting some trees in the shade is a wise policy. I do that too. It’s really important to be alert to changing weather and how it affects our trees.

      Long term growing in the shade will work for a few shade-loving plants, but we don’t work with many. Yet, too much intense, long, hot sunny days will weaken most of the traditional bonsai species and site modification with shadecloth is a great idea. Fogging is also a very good thought in really hot climates, as long as the water doesn’t actually touch the leaves or one might get hard water deposits.

      Like anything I write on this blog, read it with a grain of salt and apply as it applies to you. Some might not.

  3. Alan Jabs says:

    apologies for the poor spelling in my comment. Seems I am all thumbs tonight. Cheers Alan…

  4. Mike Miller says:

    A few things to consider that I’ve not read mentioned which would support Michael’s contention are bugs& diseases.
    I live in the Seattle area and have a special affinity for Japanese Maples. My property is sprinkled with a plethora of Doug Fir, Western Cedar, Bigleaf Maple, etcetera. Growing Japanese Maple bonsai can be challenging in terms of individual specimens’ preferential micro-climate (particularly on hot summer days). I’ve found that sheltering from some hot afternoon sun under the protection of my 100 foot cedars to be quite beneficial. But if I leave them under the landscape trees for too long (weeks-to-months), or in rainy weather, my bonsai are likely to end up with the same bugs & diseases that plague their larger cousins. We’ve all been taught that it’s a mistake to allow our bonsai foliage to touch the foliage of other trees on our bench. This is a different application of that same principle. Critters can fall or jump just as easily as they crawl. “As above, so below.”

  5. Mitzi says:

    I over pruned my juniper and now have juvenile grown on many of the tips. What can I do at this point?

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