Soil Grow is for vegative stage. Growers Ark Soil Food is formulated for growing in soil or an equivalent media (peat based or peat free compost, reused compost, fresh garden compost, manure based compost or a mix). Our Soil Food is a one part food and contains calcium and magnesium in addition to N.P.K. It is manufactured from high grade salts and EDTA chelated trace elements for the maximum ease of uptake by the plants. The Soil Food also contains humate as even when growing in soil the addition of extra humate (particularly the highly active form we use) is beneficial to plants.