How To Harvest Root Crops All Winter
Well, it looks like winter will be arriving here starting today – nights down into the teens, daytime highs in the 30's, and a few inches of snow expected next week. Time to put my root crops to bed for the winter!
I grew my carrots, beets, parsnips, and turnips inside wooden cold frames, without any lids. To make it easier to harvest my root crops over the next few months, when winter arrives I cut the leaves off – leaving a couple of inches of stems sticking up to help me find the roots.
Then I filled the cold frames full of leaves – though you can also use dried grass cuttings or straw. I have about 8-10” covering my root vegetables. Colder climates might need deeper mulch.
I don't want the mulch to get wet and freeze solid. That would make it impossible to harvest my roots during very cold weather. So, we use clear corrugated plastic to cover our cold frames. These we leave naturally ventilated, so they won't overheat too much during warmer winter days in our climate.
Some gardeners choose to bury their root crops under tall, mounded piles of mulch and then cover the pile with a large plastic sheet. Just be aware that heavy snow can compress the mulch and may reduce it's ability to insulate the crops. Also be sure to anchor the plastic down well, as strong winds might blow it away.
Whenever I want to harvest my roots, all I need to do is remove the covers, brush aside the leaves, and dig them up. As my garden beds are raised nearly 18” tall, the soil will start freezing from the outside of the beds first, working its way towards the inside. I'll start harvesting the root crops closest to the sides of the cold frames first.
In my climate, the soil rarely freezes solid in the middle of my cold frames – if the soil is covered with deep, dry mulch, and I have a solid, clear cover that provides some solar heat. Beets and turnips won't last the whole winter under mulch where I live, so we make sure to finish harvesting them before mid-winter. But we can harvest carrots and parsnips through early spring.
As spring approaches, be sure to finish harvesting your root crops before they start sending up new leaves. We put ours in our refrigerator during April and May, before the spring crops are ready to harvest. The quality of the roots deteriorate if they are left in the ground when they start growing again.
We don't have a root cellar, so mulching our root crops in our garden is one way we can extend our winter harvest!