Winter vegetable harvests are carried out when the pantry is packed to the brim. When shelves are full, the only way to store vegetables is to leave them in the ground in the tunnel. Although it seems detrimental to plants, favorable conditions will be achieved with proper protection of the polytunnel. Growers who intend to improve storing conditions of plants often use the greenhouse for this purpose.
This method of storing plants in garden tunnels is neither innovative nor often used, as vegetables and fruits can be bought in stores all year round. Using this method can be another valuable experience for gardeners looking for new challenges during winter. On the other hand, proponents of permaculture often operate that way to have constant access to fresh goods, and just like vegan and vegetarian who value their independence, can easily limit the purchase of vegetables in stores. Remember, however, that in order to store plants in the soil, you need to select species and varieties that stand out for their resistance to frost and cold.
Resistant to frost
Not all plants can withstand temperatures below 0 ° C. Heat loving vegetables such as tomatoes, peppers and lettuce can get damaged even by the lightest frost, therefore they are planted first to have enough time to ripen, avoiding situations where summer yields get exposed to low temperatures late in the season. Just like there are plants susceptible to cold, are there any with a high resistance to frost? Many of us probably encountered such species and varieties or at least heard of them. These are “elite” vegetables that do not stop growing even in extreme conditions, eventually halting at -12 ° C or even -17 ° C for some of them. These tough vegetables include:
- Brussels sprouts
- leeks – winter varieties
- root parsley
- scorzonera hispanica
Growing vegetables during winter in a polytunnel
Freezing (and defrosting) does not in any way impair the quality of the plants listed above. Although they are very resistant, it is worth growing them under cover. The polytunnel is used not only to extend their growing cycle but also to protect them from winter. Soil that has not completely frozen will be much more favorable and the yield in such substrate will start to grow much earlier.
The above mentioned plants, thanks to a greenhouse, can remain in the soil until January. As the following months become warmer, it is worth giving the plant a moment to rest. However, it can be difficult to remove them from frozen grounds in the case of root crops. In the garden tunnel, we do not have that problem.
Plants wintering in the ground
Leaving the plants in the ground is a very old method; in the old days, it was one way to store goods. Plants can be harvested on a regular basis, which helps to avoid most storage diseases.
Depending on climate, such action will only be effective with a few species. They can be divided into two groups: frost resistant vegetables to -5 ° C and heavy frost-resistant vegetables.
Light frost resistant vegetables
This type of plant is harvested in late autumn and beginning of winter. The crop of this group must be sheltered so that it cannot get damaged by temperatures lower than -5 ° C. Solid cover and galvanized foil tunnel should be sufficient. However, if the gardener has limited space or does not want to allocate a full-size tunnel, a smaller structure can be used.
- Crambe maritima
- Broad bean
Cold and fully frost resistant vegetables
There is a large group of plants that is characterized by high resistance to frost. Representatives of this group are able to withstand temperature dropping down to -17 ° C. They can be harvested throughout the winter. This kind of crop become a valuable addition to vegetables purchased in stores. Below are listed some of the most resilient vegetables:
- Brussels sprouts