How to Grow Parsnips in Containers

Blend equal parts of peat moss, pasteurized soil and vermiculite. Mix in ½ tablespoon of 14-14-14 slow release fertilizer for every 1 gallon of soil mix.

Set an 18-inch deep container in a location that receives six hours or more of daily sun, and then fill it with the prepared soil mixture. Use a container with bottom drainage holes and that is at least 18 inches wide. Water the soil until moisture drips from the bottom holes and the soil becomes evenly moist throughout.

Sow the parsnip seeds ½ inch deep. Space the seeds 1 inch apart in rows and set the rows 4 to 6 inches apart inside the container. Mist the soil surface with water to moisten it after planting. Water with a gentle spray as needed so the top 1 to 2 inches of soil remains moist until the seeds germinate, which can take up to three weeks.

Cut off the excess parsnips that germinate at soil level with scissors so the remaining plants are spaced 4 inches apart in the row. Avoid pulling up extra seedlings, because pulling may disturb the roots of the remaining plants.

Check the soil moisture daily in the container. Water when the top 1 inch begins to feel dry, adding enough water so that the excess moisture drains from the bottom of the pot. Containers can dry out quickly and may need watered daily.

Check the underside of the parsnip leaves for pests, such as aphids, that feed on the sap in the foliage and weaken the plants. Rinse pests off with a sharp spray of water. Container-grown parsnips rarely suffer from severe pest or disease problems if you keep the leaves rinsed.

Dig up the parsnip roots for use when the plants are at least 100 days old, or about 3 ½ months after germination. The roots develop the best flavor if you harvest them after one or two fall frosts have occurred.