I'm new to container gardening, after years of tending perennial beds. So, it's trial and error. Two weeks ago I put a new hosta in a fairly large self-watering container, along with a coleus and a spike. Cute combo. Anyway, quite a few leaves on the hosta were yellow this morning. Too much water? I haven't gotten the hang of the self-watering container; so perhaps I've added too much water. The unusually hot weather sent me into rescue mode this week. The pot sits on a covered porch and gets about two hours of late day sun. I mixed the soil - mostly peat, compost, perlite, and a handful of granular organic fertilizer with a very small amount of good top soil.