So I recently picked up a Pinus Strobus, Eastern White Pine, from Home Depot. It’s probably in it’s fourth year and it looked really healthy. I had a heavy dose of fertilizer on it and went away to Chicago two weeks ago for 4 days during that intense heat wave. I know in Chicago the temperatures reached over 100 degrees and the “feels like” temperature was something like 117 at one point. I live 4 hours west in Michigan on roughly the same latitude. I had thoroughly watered my plants before leaving and promptly when I arrived home. The pine was in full sunlight.
Upon arriving home, I noticed the newest growth on the most vertical candle was yellowing as was the top third of new growth elsewhere. Almost overnight the same yellowing needles had completely browned and fell off at the slightest touch. The rest of the needles seem fine with the exception of a few random yellow ones at the bottom of the trunk. Could this just be sunburn as a result of my unpreparedness?
I water daily. Some trees twice or even three times a day. True my trees are in Boon’s Mix for substrate, but even my nursery trees that are still in their original grow pots get watered once a day or at most, every other day. I am on the coast in zone 6B.
The good thing is that Strobus are tough trees. You may have only stunned it and not killed it. If it survives, it may even backbud which is not a guarantee with strobus at all.
Just fyi, because of the long needles, lanky growth, big internodes, and rubbery branches, most strobus make garbage bonsai. I have some but that is because I dug them locally so they were free to play with.
Hey, Carl. In a few of the archive videos I’ve watched recently, Ryan suggests that you should dial way back on fertilizer during the intense heat of summer. He says that it essentially acts as a salt in the container, and sonic competes with the roots for water uptake. I wonder if this might have been a contributing factor? We got hit with the same heat wave here, and I was having to water some trees twice a day. Was this in bonsai soil, or was it still in nursery soil?
I’ve also seen similar problems yesterday, after a week of being out of town and having the trees cared for while gone. I still have some fertilizer on some of them, so maybe I should remove it. As @Alex_the_potter mentioned, Ryan did talk about fertilizer during hot summer. But, it’s hard to tell when the “summer” has begun and the trees have gone to sleep for a bit. I’m still learning myself on my trees.
My summer weather is in the 110-120 regularly, and my plants can’t go for 2 days without water, even when they aren’t in full sun.
I don’t want to sound mean, but you very well might have killed the tree, or at least set it back a year or two, depending on how much die back you have.
@Alex_the_potter@mm1313: I wondered the same thing about the fertilizer myself. And yes, it’s still in the nursery soil. In the 5 Needle Pine Nuances video, Ryan says that when the sheathes fall off, the plant is no longer affected by fertilizer until the fall as the foliage is done growing. Also, because at the time of that intense heat wave the temperatures weren’t constantly at 90 degrees, I figured it’d be okay. I was trying to even out the “water pendulum” by thoroughly soaking the container knowing that I’d be gone for a few days and hoping the nursery soil would retain water longer.
Oh well I guess lol. I really was just wondering if this sounded like sun burn so I know what it looks like if it happens again as opposed to some kind of disease or pest.
@el_cheezer You don’t sound mean, don’t worry. But thank you. And I’m pretty sure it’s not dead, just set back a while. It’s still got all of its foliage from the past couple years and probably 50% ish of this year’s.
Carl, was the soil in the pot dry? As a number of people have commented, 4 days is a long time without water in the bonsai world. That’s why insanity is a requisite for growing bonsai. You can never leave your trees for very long during the growing season unless you have a knowledgeable waterer to come by. If the soil was the original nursery soil which is heavy on the organics, there is greater water retention like you notedl.
Also if it was inorganic, chemical fertilizer, this could contribute to the dieback when linked with the lack of water. Chemical fertilizers can burn the foliage.
Trees in the wild are subject to dry spells. They can take some foliage losses. If your tree is still green, you are still in the game. And a little wiser. Don’t give up on strobus. Learn all you can about them. Ryan has a clear approach. And then go and collect one with old bark. You will find them under a rainbow.
@DavidJ: Thank you for the encouragement. The soil was dry when I got back and it’s organic and had organic fertilizer on it which didn’t help I’m sure. I tried to thoroughly soak it before I left, hoping that the nursery soil would retain enough until I got home. Lesson learned lol.
@el_cheezer: Yes, the tree stopped declining the instant I watered it. The remaining needles are green except where a few others got burned on the tips. Besides that, I think everything looks good! I’m hopeful.
So there are methods to keep soil moist when away from home. A container filled with water and a cotton wick running into the pot will keep moisture for several days. Also the glass bulbs that are enclosed with an opening below the soil will slowly add water to the pot. I have a friend that trades watering duties when we are on vacation, and he also gives constructive criticism for techniques that I might try to improve my garden and trees.
