Can leeks survive winter in the ground?
Written by
Olivia Mitchell
Reviewed by
Prof. Charles Hartman, Ph.D.Leeks can be overwintered, but it's crucial to understand exactly how cold-hardy they are. The cold makes leeks sweeter, so if you prepare them correctly, those hardy little vegetables will survive a winter blast. In some regions, you can even harvest fresh leeks throughout the entire winter.
Variety Selection
- Choose cold-hardy types like Tadorna and Bandit
- Avoid summer varieties with low frost resistance
- Check seed packets for winter hardiness ratings
Pre-Winter Care
- Stop fertilizing 6 weeks before first frost
- Water deeply before ground freezes
- Remove diseased foliage to prevent rot
Mulching Techniques
- Apply 6-8 inches straw before temperatures drop below 25°F
- Cover with row fabric during extreme cold snaps
- Add evergreen boughs for extra insulation in zone 4
A proper application of mulch will protect leeks from freezing. Apply 6 to 8 inches of straw before icy temperatures settle in below 25°F (−4°C). Avoid materials, such as leaves, that become compacted, leaving little air pocket insulation. In zone 4 and lower, add evergreen boughs over your straw for additional protection. Check your mulched bed periodically throughout the winter and replace any sections that have been displaced by wind or animals.
Harvesting techniques change when the ground is frozen. At a 45° angle, insert a digging fork under each plant and use the prongs of that tool to lift it out. If the soil is rock-hard, place the leeks to thaw in cool, running water. Don't twist frozen stems, for they break very easily. The leeks are always the easiest to extract when that little thaw occurs at midday.
Monitor during the winter for early signs of rot or damage from mice and other rodents. Whenever there is a warm spell, lifting the mulch should be done. If decaying leaves or other refuse are found, they should be removed without delay. Ventilation must be done at times when the temperature is above freezing to prevent the tendency for moisture to accumulate. Protection should be replaced when the temperature grows colder again.
Spring Care Revives Plants over Wintered inside Gradually remove mulch when the weather is above freezing. Trim back all winter-damaged leaves to encourage new growth. Fertilize with a balanced fertilizer when green growth appears on the plants. Most of the crop plants will produce one or more early spring harvests before bolting.
Discover the flavor surprise of overwintered leeks. The cold turns the starches in the stems into sugars, giving them a sweeter flavor. Harvested after a frost, these leeks have a complex flavor that makes fabulous soup and makes for painfully good roasted dishes. Your winter will taste quite amazing!
Read the full article: 10 Essential Steps for Growing Leeks
