Rutabagas grow well in fertile soil containing plenty of organic matter. Before planting, work compost or well-aged organic material into the soil to improve fertility and structure. A balanced vegetable fertilizer may be useful if your soil lacks essential nutrients, but excessive nitrogen should be avoided because it can encourage leafy growth rather than desirable root development. A soil test can help determine whether additional nutrients are needed. Keeping fertility balanced, rather than heavily fertilizing throughout the season, generally supports healthier roots and steady plant growth.