Because it is a fast grower, you can still get a massive, beautiful Lemongrass plant in just one summer in Oklahoma. Wait until late April or early May to plant. If the soil is colder than 60°F, it will just sit there. Once the Oklahoma humidity and heat kick in (June–August), it will explode with growth. Since it won't survive the winter here, many people grow it in large decorative pots on their patio. If you want to keep it alive, you can bring the pot inside to a sunny mudroom or garage before the first frost in October. Lemongrass is a thirsty plant. It needs full sun but wants consistent watering. If it dries out too much, the tips of the leaves will turn brown and crispy.