|I have one of these shrubs in a deep pot (hip high). I bought it this summer. Lately I'd noticed a yellowing of the inside foliage. I have a fear of overwatering conifers (killed one that way once) and so I thought perhaps I was watering it too much, even though I was watering at most once every two weeks. Now the inside foliage has turned brown and is somewhat brittle, easily removed: if I brush it, it will fall off. So far there isn't a lot of brown foliage on the shrub's interior but it does seem to be expanding. Is this then due to underwatering on my part? The original root ball still feels solid (under the loose potting soil) - should I break it up and re-pot it? I found some info on the web that suggested potting soil isn't the right kind of soil for this shrub - I have Black Gold Premium Potting Soil in the pot. I saw also mention of Chlorosis, but the leaves are no longer yellow, just brown. Help. :)|
|It's really difficult to judge just how often to water a containerized tree. Soil type, weather, and season all contribute. The best thing to do is water thoroughly by saturating the potting soil, then allowing the top 2-3" to dry out before watering thoroughly again. It's normal for the oldest foliage (toward the center of the plant) to brown and drop eventually. As long as the new growth is healthy, there's nothing to worry about. However, if there seems to be an excessive amount of browning, you might closely inspect the affected parts of the plant for insect or disease problems. Fungal diseases can start on the interior of the plant; spider mites can find protected areas in which to feed and breed. Use a magnifying glass to check things out. If you suspect an insect or diseas problem, take a sample of the foliage to your local Cooperative Extension office for positive diagnosis. Helpful folks there can provide control strategies. (OSU Cooperative Extension offices are listed under your County in the white pages of the phone book)
Best wishes with your tree!