With this recent cold snap, I've held off harvesting from my winter garden. The cold frames have been firmly shut for over a week and I've left the mini hoop tunnels hunched in the the garden surrounded by insulating snow, waiting until the extreme temperatures have become more seasonal. The only beds I have been harvesting from are the ones that were mulched in late autumn and hide a buried treasure of super-sweet root crops.
Protecting hardy vegetables with an insulating layer of mulch is perhaps the simplest and most cost effective way to extend the harvest of root crops, as well as vegetables like leeks, brussels sprouts, kale, collards, winter cabbage and even kohlrabi. Yet, there are several other ways that you can put ‘the magic of mulch' to use in your vegetable garden. For example, I also use mulch to protect against winter erosion and have had great success with the technique known as ‘sheet mulching'. Not only does it enrich the soil, but it also attracts an abundance of earthworms.
3 Ways to put mulch to work:
1) To Extend the Harvest - Like most avid vegetable gardeners, I learned early on that many fall and winter vegetables, such as carrots, taste better after they have been sweetened by a few frosts. The same rule applies to parsnips, beets, brussels sprouts and even the leafy foliage of kale. These cold season crops are seeded in mid-summer and by late November, it's time to top the bed with a one-foot thick blanket of shredded leaves or straw and add a fabric cover like an old sheet or row cover to keep the mulch in place over winter. Anytime we want to harvest, we just push back the cover, move aside the leaves and dig in the soft soil for our veggies.
2) Preventing Soil Erosion - By mid-autumn, most of our garden beds are filled with cold tolerant vegetables for a winter harvest, but a few of the beds lie empty, with the remnants of late summer and early autumn crops. At this point, it's too late to seed additional edibles and so these beds will remain vacant until the following spring. I don't, however, want to lose any of my rich garden soil to winter erosion, so I top the beds with a mulch like straw, shredded leaves or chopped seaweed, which will also help prevent weed growth. Once spring arrives, the remains of the mulch should be removed and composted or dug into the garden to enrich the soil, giving it a few weeks to decompose before you plan on planting.
3) Soil Enriching or Starting a New Garden - Sheet mulching is a fun and easy way to build a new flower or vegetable garden with no digging required. To begin, you need to select your site and gather a variety of organic materials to that will be layered together and allowed to compost down, creating a rich planting bed. To make these layers, start by covering the grass or earth with cardboard or wet newspapers. Then add your layers, alternating ‘green' and ‘brown' materials. Green items are often called the ‘nitrogen' or ‘wet' materials and include things like kitchen scraps, coffee grounds, tea bags, seaweed, grass clippings and aged manure. For the brown or ‘carbon' materials, stick to items like shredded leaves, shredded newspaper or straw. Layer the materials so that your finished sheet mulch is at least 12 to 18 inches deep. Water and give the bed 4 to 6 weeks to break down before planting.
Niki Jabbour is the author of The Year Round Vegetable Gardener (2012 Book Award American Horticultural Society) and the host of The Weekend Gardener radio programme, which has gone dormant for the winter. Find her on facebook at twitter @NikiJabbour.