Hi All,
I am writing for assistance with my first bonsai--I believe it is a Chinese juniper. I am aware that junipers are meant to be kept outdoors and many of you will advocate against keeping it indoors at all. Unfortunately, having it outdoors permanently is not an option under the circumstances. That being the case, I am asking for help with keeping the tree alive under the circumstances available, wherein I can keep it outdoors about a third of the week. I purchased the three about three weeks ago after the shopkeeper responded affirmatively when I asked whether I would be able to keep it alive in my office if I rotated it outside every weekend. But my current regimen appears not to be working and the leaves are progressively yellowing.
Sun/Outdoors
This bonsai is in my office. I work in Palo Alto near San Francisco, where the outdoor temperatures are currently in the mid-70s and it never snows or gets too cold. Monday-Friday, I keep the bonsai in my office in front of a large but unopenable window (see picture). The window gets a good bit of indirect sunlight for most of the day and direct sunlight 1-2 hours at sunset (and I assume sunrise). Fridays at 5 p.m. I bring the tree outdoors to a patio area, where it remains in the sun until I bring it back inside on Mondays at around 10 a.m.
Water and Food
I am aware that junipers often die from overwatering and prefer to be a bit thirsty. Accordingly, I have been watering it every 2-3 days when the soil feels dry to the touch after I dig about a half inch below the surface with my hand. I also mist the tree 1-3 times a day during the week when it is indoors. The article I am linking to below indicates how a (Japanese) juniper can be kept alive
fully indoors in San Francisco. As the article recommends, I purchased a humidity tray and will place the bonsai pot into the tray to help with humidity. I hope that will help with or solve the problem, but the tray has not yet arrived and the tree has been without that advantage thus far.
homeguides.sfgate.com/grow-japanese-juniper-inside-74905.html
I also fertilized the top of the soil with organic greenish yellow fertilizer ball that I pour water over.
The Problem
The tree was fully green during the first week or so that I had it indoors. Then I brought it outside for the weekend and noticed on Monday that some of the leaves were yellowing at their bases and some others had dried out and were easily falling off when plucked with my fingers. The soil was very dry when I brought it in, so I thought I had maybe erred too far on the side of underwatering and it dried out too much over the weekend when it was in the sun. I took it back inside for the week and believe that it got better or at least no worse during that week, but it's hard to notice change when looking at it every day. On Friday evening I took it out again and this time I thoroughly watered it to make sure that it had enough water while it was outside in the sun for the weekend. But today I brought it back inside and it is obvious that many more leaves are yellowing/drying out, some are kind of sagging to the side rather than standing perkily upright, and the small branch that had the first yellow leaves now appears to be mostly brown/dead.
I get the sense that rotating it outside is what is killing it--because it becomes much worse for wear over the weekend. But as I said before, I can't be sure. I have read that dramatic changes in environment can harm junipers, such as when they are brought from indoors into scorching sunlight instead of gradually into indirect/shady sunlight. But the environmental change when I bring it outside isn't dramatic--it's coming outside into a warm but not scorching hot and dry environment. Can this weekend change in environment be what is killing it? I have read that fully indoor junipers typically look fine for many weeks before they start dying, so the relatively rapid decline of my tree over two weeks with what I think are relatively good partially indoors conditions is surprising and concerning. I feel like at three weeks it wouldn't be yellowing this rapidly even if I had left it fully indoors?
Solutions?
What can I do to try to save my tree? I have the humidity tray coming and I hope that helps--it sounds like some people in my climate are able to keep junipers fully indoors with such trays. But what else can I do? Is my indoor/outdoor rotation strategy unsound? Keeping it fully outdoors is not an option, so should I try keeping it fully indoors with the humidity tray, as in the linked article? Should I double down on the rotation strategy and bring the tree outside every weeknight and bring it back inside every morning, a well as weekends? Should I prune away the dead/dying branch and the yellow leaves?
Any assistance is much appreciated. Thank you.