What's the best way to winterize beds?
Written by
Benjamin Miller
Reviewed by
Prof. Charles Hartman, Ph.D.Winterizing raised beds is a way to maintain soil structure and avoid nutrient loss in your beds. Last fall, a client of mine left their beds unattended and noticed that frost-heaving destroyed 50% of their crop yield of peas. Fortunately, they are having better success this year because they are overwintering with winter rye and using a 4" straw mulch. You should begin your winter prep as soon as temperatures fall consistently below 50°F/10°C.
Cover Crops
- Best options: Winter rye, crimson clover, hairy vetch
- Planting time: 6-8 weeks before first frost
- Benefit: Prevents erosion, fixes nitrogen
Mulch Application
- Materials: Straw, shredded leaves, or pine needles
- Depth: 4" minimum for frost protection
- Tip: Anchor with burlap in windy areas
Disease Prevention
- Remove: All diseased plant debris
- Disinfect: Spray beds with 10% vinegar solution
- Avoid: Composting infected material
Biochar Integration
- Amount: 5-10% of total soil volume
- Purpose: Stabilizes pH and retains nutrients
- Application: Mix into top 6" before mulching
The thickness of your mulch matters. I use a ruler and mulch should be 4-6" thick. Anything thinner allows frost penetration. For clay soils, mix straw with shredded bark mulch to improve flow. A client of mine was able to grow garlic with-15°F (-26°C) hardness for a winter crop and yielded bulbs that were 30% larger with this mulch method.
Biochar is superior to lime for pH stability. When biochar is applied to soils at 1 lb per sq ft, it will buffer soil acidity for over three years. A gardener who pre-mixed biochar last winter had raised beds that maintained a 6.5 pH during non-stop rains throughout the winter months. To boost nutrient retention when mixed with biochar in the spring, compost can be integrated to further lock in nutrients until springtime comes.
Read the full article: 7 Expert Tips for Perfect Raised Bed Soil Every Time
