I would blame the slow ripening and lack of vigor on the limited amount of sun rather than on the potting mix you are using. You really need more than 4 or 5 hours of sun a day, and the cloudy weather is reducing the sun exposure even more.
I have plants in MG potting mix in 5-gallon buckets in a sunny area and they are keeping pace with the plants in the garden. Can you find a better spot for your containers?
|