Winter Garden Crops
While many gardeners consider winter to be a dormant time in the greenhouse, there is no reason that you can’t enjoy a colorful and delicious garden even during the coldest months. Depending on your climate, you may also be able to grow these plants without heat in your greenhouse or even outside. In order to achieve the best results, be sure to read the information available about the varieties you are planting. You’ll want to make sure that your plants are growing at an appropriate temperature. (To make sure, you may want to purchase an inexpensive Min/Max thermometer.
If it looks like your temperatures are too cool for the varieties you want to grow, check with local seed catalog companies. Many of these companies provide seeds that are developed to perform especially well in your climate. If you seem to have trouble finding what you are looking for, consult local nurseries for their suggestions.
Consider trying these vegetables in your cold-weather greenhouse:
- Brussels Sprouts
- Fava Beans
- Swiss Chard
You may even have luck with these flowers (which can be grown below 45°F):
- Christmas Cactus
- Sweet Pea
When growing in the winter, your plants are likely to have different needs than they would have during the summer. Drastically reduce the amount of water you provide; in most cases the first inch or so of soil should be dry before you water again. Also, because growth slows during the winter most plants will require only minimal fertilizer. Most plants will be just fine without it provided that you have some good organic content in your soil.
Even though temperatures are cooler in the winter, plants still need some ventilation in order to stay healthy. The greenhouse will need some gas exchange so that the plants have fresh carbon dioxide and can properly photosynthesize. Some gentle air flow also keeps pests away and will encourage sturdier stem growth.
While these plants may tolerate cooler temperatures, they may not tolerate low light levels well. Frequent cloudy weather may require the addition of a grow light.
For more ideas on plants to grow, including planting schedules, we highly recommend the book The Greenhouse Gardener’s Companion by Shane Smith. It’s sure to answer all of your greenhouse questions!