This is a small boxwood, about 10 in tall. For the last 2 years it's been battling boxwood blight here in southern NY but this summer I felt it had turned a corner. I repotted and had been pruning off dead leaves and the new growth was slow but steady. It has 3-4 chips of BioGold on the soil surface.
About a month ago I moved it into my basement with 9 other non-hardy trees, boxwoods and ficus, and put them under a full spectrum grow light for about 18hrs/day.
Under the grow light they had a nice growth spurt, new leaves all over the canopy. But in the last 5 days all the new growth has gone yellow as in the picture. A few of the leaves on some ficus plants under the same light have turned yellow also but nothing like this.
I'm wondering if this could be too little water? I had been watering every other day but then I noticed fungus gnats in the area so I decided to let the soil dry out a bit to alleviate the gnats. I didn't water for 4 days, the gnats went away and the soil did not look dried out at all. Perhaps too much water?
If the picture can us something I'm all ears.




thanks,

Rob