Photo Credit: Rebecca Anne Cole
Cabbage seedlings, those precious little plants that have been nurtured so tenderly throughout the winter months, will eventually need a final place to call home. The effort expended to start each plant from seed, careful watering and adjusting under grow lights to give them the best start in life, could all be lost without proper planning and care when it comes to setting them out for permanent placement in the vegetable garden.
Knowing when and how to transplant the tender seedlings is essential to successful growth and production of abundant cabbage heads. Cabbage plants are one of the first vegetables to be set out in the garden after weeks under indoor grow lights, usually in early spring. Once the plants have developed two to three true leaves, they are ready for transplant. True leaves, although small at first from underdevelopment, resemble the plant’s mature leaf in shape and color. They differ from sprouting leaves, which appear just after the seed has germinated.
Photo Credit: Rebecca Anne Cole
Prepare the soil with rich compost a couple of weeks before transplanting. Decayed leaves work well when they are incorporated several inches into the soil. In the fall I shred leaves and turn them into the soil of the cabbage bed so that the material is well rotted and ready for incoming spring plants. Cabbages needs full sun and moist soil for proper growth and development, so select a spot with plenty of sunlight exposure.
Set delicate cabbage seedling trays outside gradually for a couple of hours, then longer each day until they are accustomed to be being outside. This process is called hardening off, and can begin for hardy vegetable plants like cabbages when daytime temperatures and consistently above 40 degrees F. Once the cabbage plants have been exposed to direct sunlight, wind, and outdoor conditions, they will be more resilient to a light frost, and acclimate to their new habitat. Choose a location where the plants can be easily moved and protected from high winds and harsh sun. I use an outdoor shelf with a cover, enclosing three sides at first then gradually exposing more as the plants become accustomed to the elements.
I aim to transplant cabbage plants a couple of weeks before the last threat of frost, to take advantage of the colder temperatures and hopefully have less hassle from cabbage devouring pests. This means that I am starting to harden off cabbage seedlings mid to late March for my zone 7a garden. The early start also allows for an earlier harvest in the coming weeks. I am mindful to cover the cabbage bed with a sheet or tarp should a late hard frost arise.
After the cabbage plants have been property hardened off and the soil has been prepared, they are ready to make their final transition to the garden. Dig a space large enough to accommodate the starter soil and plant roots. Gently nestle the roots into the hole and pack in enough soil to support the plant from the base, leaving the stem and leaves exposed.
Depending on the variety, cabbage plants need 12-18” spacing in the garden. I like to use smaller, conical shaped cabbage head varieties like Kolibos and Early Jersey Wakefield, which require about a square foot per plant. Larger varieties such as Brunswick and Aubervilliers need more space to thrive and produce significant heads, so allow 16-18” or more in the garden per plant.
A layer of mulch applied after transplant to help retain water and keep weeds at bay. Biodegradable paper weed barrier has worked well for me in my cabbage beds. After I have dug all of the holes, I lay the weed barrier paper over the bed, then X out spaces to match. The plants are then set into the holes and covered with soil, which holds the paper in place. Putting in the extra work at the time of transplant is well worth the effort a few months later when I am not breaking my back pulling weeds from the cabbage bed.
When the cabbage plants are settled into their new places, water and weed as needed. The early start outdoors will help minimize insects and allow cabbage heads to develop for harvest in time for a second planting. I like to follow behind with snap peas and green beans, as the ground will be sufficiently warmed by the time the cabbage heads are harvested.