At long last, we’re getting close to thinking about planting our veggie gardens.
Don’t get ahead of yourself, though. Stick with cool weather vegetables first and know that even they might need protection as there may still be some frosty nights. Cool weather crops include the brassicas, leafy greens, spinach, radishes and peas. Hold off with warm weather plants like tomatoes, eggplants, squash, corn and peppers until the soil warms up.
If you are starting from bedding plants or ones you seeded indoors in the last month, be sure that any plant starts you set out in the garden have been “hardened off” (gradually acclimated to the outdoor weather). This can be done by taking the plant outdoors during the day — at first in the shade and gradually in the sun. Bring them back into the house in the evening.
Early spring gardeners have options available to moderate temperatures and allow plants to grow in the garden while there is still a chance of frost.
Cold frames are used for starting seedlings and hardening off plants. They can be purchased or you can make your own with plywood on a frame and old window sashes or plastic for the lid or covers. Most are 3 x 6 feet but are often built in order to fit the old windows. Make the backside higher than the front and face it in a southwest direction to maximize the sun’s warming benefits. Another option is to nestle your cold frame next to a building for added heat and protection.
Some choose to surround the box with insulation. Make sure the cold frame has a venting system to let the trapped hot air out during the afternoon. Make sure you can prop open the windows or roll up or take off the plastic cover.
If that seems like too much work, you can also take your chances by putting your plants in the ground and covering them in the evening. Say you have planted your broccoli, cauliflower and cabbage in wide rows and a cold night is predicted. You can cover your plants with floating row cover, which is made of a polypropylene-spun fabric. It lets air, light and water through the fabric but traps the heat around the plant. Make sure you anchor the edges in case the wind comes up.
If you don’t want to have the plants touched by the covering and they are in a row, a low tunnel can be constructed. Flexible PVC pipe can be bowed over the row and stuck in the ground, or the ends of the pipe placed into stakes that have been hammered into the ground. It is then covered with cloth or plastic and the ends secured with weights. This allows for venting if too much heat collects. Once the last frost date is past they can easily be removed and stored for later use.
Another option for single plants are cloches. Traditionally, these were glass jars that were taken off the plant in the heat of the day and returned later in the day. An easier system is cutting the bottom off a 1-gallon milk jug and placing that over the small individual plant. During the day the cap can be taken off to let the hot air vent and the cap replaced later in the day.
A variation of this is the commercially available “wall of water,” a double-walled plastic structure placed so it surrounds the plant and is filled with water that heats during the day and sends the heat to the plant at night.
Another great option used by gardeners who have raised beds are high tunnels. You will need a framework of flexible, small-diameter PVC pipe and some stakes placed in the dirt at the edge of the bed. The pipe goes over the stake, is gently bent over to the other side of the bed, and is attached to that stake. The framework is then covered with floating row covers in milder temperatures or plastic when it is colder. Open the ends to vent when it gets hot. The other nice option with this framework left in place is to add shade cloth in the heat of the summer to keep cool weather vegetables like lettuce from bolting.
Once you have your chosen system, it is easy to use each year as you get a jump start on your garden or extend your garden harvests into the fall and enjoy even more fresh homegrown vegetables.