Here at Debs we've been using Natures Source Fertilizer on all our plants in the Greenhouses and our personal plants for years now. It is the only fertilizer we recommend. When you pre-order it, we will hold it here for you until you pick up your plants in June. This is a liquid plant food with easy to use pump. just do 3 pumps per large watering can for outdoor plants and 1 pump/large watering can for indoor plants.