Frosty Greenhouse

Overnight temperatures dipped into the mid-20s last night and early this morning. Winter is slowly creeping upon us. Although the greenhouse is covered in heavy frost each morning, I notice that the polycarbonate walls are clear of frost immediately next to my low-tech thermal heat device---a black plastic garbage can filled with water. It absorbs heat during the day and releases it at night, modifying the air temperature inside the greenhouse ever so slightly. As long as daytime temperatures are above freezing, it's a useful technique. Soon, I'll empty the water or else I'll have an ice-box in the greenhouse, which will modify air temperatures in the wrong direction. It's good to know that the garbage can technique is making a difference.

We're still growing spinach and herbs in the greenhouse. Spinach survives sub-freezing temperatures and tastes crisp and fresh. In the photo above, you can see that we've covered the raised bed with hoops and row fabric. This extra layer of protection will ensure survival over the winter. The greenhouse is also cold winter storage for a few small trees, specifically a zone 5 brown Turkey fig tree, and several small oak trees that we started from acorns a few years ago.

Our unheated greenhouse at Red Bucket Farm is small and humble, but it remains a useful tool to extend the seasons in fall and early spring. If you've ever dreamed of owning a greenhouse or hoophouse for gardening, I recommend giving it a try.