You could be watering too often. The yellow leaves can indicate over watering. Is the plant sitting in drainage water? This could cause root rot. I suggest you poke a finger into the soil and water when the top inch of soil is dry. Yellow foliage can also be a sign of lack of nutrients. If you have not fertilized yet this year you can add some Osmocote granules around the base of the plant and work them gently into the top inch of soil. Then when you water the fertilizer will be slowly released to the plant as it needs it. Good luck, I think your plant will be looking better soon. Keep growing, Marianne Binetti