Cold December is the darkest month of the year. Growth is at its slowest and supplemental light is needed if you choose to actively grow.
Temperature
For a cool greenhouse, your goal is a minimum night temperature of 42°-45° F and a maximum day temperature of 55°-60° F. Warmer temperatures can cause soft, spindly stems.
Ventilation
Ventilate sparingly to remove condensation. Use caution not to create a strong draft or extreme drop in temperature.
Watering
Water mid-morning as needed. Keep plants and soil on the dry side except if they are in bloom.
Pest and Disease
Check plants regularly. Deadhead flowers and remove yellow or diseased leaves.
Winterize / Insulate
In most areas, the coldest winter weather is still ahead. For energy saving ideas, visit our Greenhouse Climate Guide tips.
Growing Fun
- Bring pots of bulbs from outdoors into the greenhouse to mature faster.
- Move any bulbs forced for the holidays into the house as soon as they start to show color.
- Start seeds of lettuce, carrots, French Bean.
- Continue to harvest cool growing veggies.
- Move holiday potted plants now flowering into the home. Water with a liquid fertilizer. Keep in a cool place out of direct sun for best results.
