Growth Requirements for Brassica Seeds

Soil

• Preparing ground prior to sowing ensures healthy and rapid seed germination. Dig the planting site as deep as possible and incorporate organic matter like compost or well-rotted animal manure into the soil. This not only fertilizes the soil with micronutrients but also helps to improve soil structure and increases the water retention capacity. Test soil for pH. Recommended pH for brassicas is anywhere between 5.3 and 6.8. Add lime to fix pH in acidic soils.

Sowing Method

• Plant seeds in well-drained, moist and firm seedbeds with 6 to 8 inches between rows. Do not plant deeper than ½ inch, as germination is impeded when planted very deeply. Sow the seeds in a thin line and water with fine spray. Once seedlings are about an inch tall, thin to a distance of 2 inches between plants. If you need to move the plants to another location, water the ground well before lifting out plants and transplanting.

Planting Time

• Under optimal temperatures of between 40 to 70 degrees F, brassica seeds take between seven to 12 days to germinate. The recommended time for planting brassicas starts during early spring, as the vegetables grow best during the cooler, moist periods of the year. Certain brassica varieties such as turnips are cold hardy to temperatures as low as 15 degree F. Turnip seeds are among the brassicas that germinate in 40 degrees F soil.

Harvesting

• The harvesting time for brassicas differs with variety but is generally spread out through the year. Kale and cabbage are among the leafy brassicas that may be harvested during winter, spring and summer. Mustard, radishes and cress are used as sprouts and in their seedling and mature forms. Seakale is forced into shoots and harvested during the middle and end of winter. Rutabagas, radishes and turnips are root crops harvested in spring, summer and winter. The seed pods produced by radish plants immediately after flowering are also used for their peppery flavor.