Grow Anywhere: Year-Round Gardening With Cold Frames

Plan the size of your cold frame. Measure and cut the 2-inch-by-8-inch boards to length to create the front, back and sides of the planter box. Karla's box uses two boards in the front and three in back. Cut six shorter pieces for the sides. Cut two of the side pieces to angle down from the back of the frame to the front.

Cut 1-inch-by-6-inch vertical supports to length. The supports should be just a bit shorter than the height of the walls. The rear wall will be taller than the front, so the supports for the back will be a few inches longer than the front supports.

Cut 2-inch-by-4-inch boards to length to run along the top edge of the frame.

Finally, cut 2-inch-by-2-inch boards to length to frame the cover.

Start by assembling the base with the 2-inch-by-8-inch boards and 1-inch-by-6-inch boards. Attach the 1-inch-by-6-inch vertical supports to the interior faces of the side boards, 1-1/2 inches from each end. These supports will help you get the stability you need to support your frame. Remember, the longer supports go toward the rear.

Run the front and back boards between the side pieces and attach them to the vertical supports. Once the base of the box is assembled, attach the two remaining vertical supports to the center of the front and back boards. Then attach the second row of 2-inch-by-8-inch boards to the vertical supports.

The lid will rest on top of the planter box at an angle. Attach the angled side pieces to the supports as well as the final 2-inch-by-8-inch board for the back of the frame. Then secure the faces of the 2-inch-by-4-inch boards to the top edge of the box.

Assemble a frame for the lid with the 2-inch-by-2-inch boards. Use a staple gun to attach 6-mil plastic sheeting to the top of the frame. Make sure the plastic is tight and cut off any excess plastic at the edges of the frame.

Use hinges to attach the lid to the 2-inch-by-4-inch board running along the rear of the planter box. Attach a handle to the front of the lid.

You'll need some way to secure the lid. Karla attached a hook to the front of the box and ran a bungee cord between the hook and the handle.

One of the most important parts of building a cold frame is insulating it. You can use anything from hay to woven mats to foam board insulation. Karla used foam board, cutting it to size to fit the interior of the box. Don't worry about attaching it because the soil will hold the insulation up.

Once you have the insulation in, it's time to add soil. Karla recommends a mixture of organic soil, compost and peat moss. Compost and peat moss are great amendments that help improve your soil's structure and add nutrients, which in turn will help your plants. Mix the soil and amendments well.

Now it's time to plant. Stay away from nightshades, like tomatoes and peppers, because they don't do well in the cold. Plant hardy greens like:

• Kale
• Collards
• Arugula

You can also try some root vegetables like:

• Beets
• Carrots
• Turnips

You can plant seedlings (sometimes called starts or starter plants) or sow seeds as Karla did. She created markers to identify each of the plants.

Once everything is planted, give your seeds or seedlings a healthy dose of water. Finally, Karla added a layer of seed-free hay or straw on top of the soil. This is another way to insulate the plants and keep the heat in the soil.