rhododendron brown spots
My rhododendron was purchased at the end of the season and I am keeping it in the house until spring. Some of the leaves have brown spots. What is wrong?
Rhododendron is not a houseplant, it needs to go to sleep, i.e. enter dormancy, to pass the winter. Late fall is not a very good time to purchase rhododendron, because of the problem of overwintering. A couple of approaches you can take. You can try keeping it in a cool, dim place; make sure the soil is thoroughly watered before setting it down, then checking the soil every few weeks, to make sure it doesn't get totally dry. The other thing would be to take it outside, in a spot protected from wind, the pot buried in the soil and mulch built up on top, the point being to protect the roots from freezing.
I don't know if this will be successful, but at least it gives your plant a chance. Come spring, you can plant it using the tips in this article, and with luck, it will start to grow: https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/rhododendron-care.htm