Turnips are versatile root vegetables, appreciated for both their edible roots and nutritious greens. Understanding their distinct growth stages helps gardeners optimize conditions for a bountiful harvest. This guide details the turnip’s development from seed to mature plant.
Germination and Sprouting
Turnip seeds typically sprout within 4 to 7 days when provided with optimal conditions. For successful germination, soil temperatures ideally range from 60°F to 85°F, though they can germinate in temperatures as low as 40°F. Consistent moisture is essential during this period, as the seed absorbs water to initiate cell division within its embryo.
Once sufficient moisture is absorbed, the radicle, the plant’s first root, emerges from the seed coat. Shortly after, the hypocotyl (primary shoot) and two embryonic leaves, known as cotyledons, appear above the soil surface. These cotyledons are distinct from true leaves and contain stored energy that fuels the young turnip’s early development.
Seedling Development
After cotyledons appear, true leaves emerge, marking the seedling development stage. These true leaves are typically visible within a few days of sprouting and possess a different shape and texture compared to the initial cotyledons. As the seedlings grow, they establish a more robust root system beneath the soil, with the taproot developing rapidly.
Thinning is an important practice during this phase to ensure adequate space for proper root development. Seedlings should be thinned to 4 to 6 inches apart, depending on the variety, to prevent overcrowding which can lead to small or malformed roots. Consistent watering supports continuous growth, and protecting young plants from common pests like flea beetles helps ensure their establishment.
Root and Foliage Maturation
The turnip plant enters root and foliage maturation. During this stage, the turnip root begins to expand and develop its characteristic shape beneath the soil. This root acts as a storage organ, accumulating nutrients and energy through the plant’s photosynthetic activity. The foliage, consisting of elongated and slightly frilly leaves, continues to grow larger, capturing sunlight for photosynthesis, which is essential for the root’s development.
Consistent moisture is important during this period, as dry conditions can lead to woody or bitter roots and may cause the roots to split. Turnips typically require about one inch of water per week, either from rainfall or irrigation, to support healthy growth. Fertilization should be managed carefully; while a balanced organic fertilizer can be applied, excessive nitrogen should be avoided as it can promote lush leafy growth at the expense of root development. Monitoring for pests and diseases remains important to maintain plant health and ensure the edible part of the plant forms and expands.
Harvest Readiness and Post-Maturity
Turnips are typically ready for harvest between 40 to 60 days after planting, depending on the specific variety and growing conditions. The roots are best harvested when they are young and tender, usually reaching a diameter of 2 to 4 inches for most varieties. Harvesting smaller turnips often results in a milder, sweeter flavor. Turnip greens can also be harvested when they are 4 to 6 inches tall; cutting the outer leaves about 2 inches above the base allows them to regrow for multiple pickings.
If turnips are left in the ground past their optimal maturity, they risk bolting, meaning the plant prematurely sends up a flower stalk and goes to seed. Bolting is often triggered by environmental stress, such as extreme temperatures or inconsistent watering, and it redirects the plant’s energy away from root development. Once a turnip bolts, the root typically becomes fibrous, woody, and bitter, and the greens may also become unpleasant to eat.