Friday, April 6, 2012
Keeping Those Plants Warm
Well, if you're like me and you fell for all the signs that we were all set to have a hot early spring...oops. Tonight is supposed to get cold here in Virginia! And of course, I have a few geraniums planted in the window boxes and I've got tomatoes hardening off on the porch. Luckily, having lived in the temperamental spring climate of Long Island all my life, I never put my tomatoes in until I'm absolutely sure we are well beyond the last frost date of spring. I keep them in pots, and they are in a nice, sturdy tray. On cold nights I just pull the tray into the garage, which is 10-20 degrees warmer than the outside air, or I pull them into the house for the night. The trick is to remember to bring them back out in the morning.
What can you do, however, if you got fooled into thinking spring was already here and you planted some tender vegetables, herbs or flowers? If there's a frost warning, you can make newspaper cones or tents and put them over the plants. Be sure to anchor them with rocks or sticks used like pegs and take them off in the morning. You can make something called a cloche, which is like a mini greenhouse, out of a 2 liter soda pop bottle or a gallon milk or juice container. Wash the container out thoroughly with soap and water and dry it. Then very carefully cut off the spout area, leaving most of the bottle open. Pop it like a cap over the plants and put a rock on top to anchor it in place. Always remove all covers from the plants during the day. Unless it's going to stay in the 30s or 40s by day, it is better to take the caps off during the day and allow for good air circulation and sunlight than to risk overheating the plants. You'd be amazed at how hot it can get under those protective covers. Newspaper will also block sunshine, which your plants need for photosynthesis to make their food.
My raised beds keep the temperature a bit warmer than the surrounding areas. A friend who owns a construction company gave me the most marvelous windows that fit right over the raised beds. He was remodeling a high school gymnasium and had to replace their windows, so these are big, metal-framed glass windows with louvers. I can put the whole window over the beds and open or close the glass if I need to. Now before I had the luxury of such windows, I used clear plexiglass anchored with rocks to make a little bit of a cold frame over my raised vegetable beds. Works just fine as long as you don't squash the plants with the glass AND you must remember to remove them in the morning. It's amazing how fast the temperature can rise inside the glass once the spring sun is up, and you don't want either cold (frost) or heat (from the sun baking through the glass) to damage your vegetables.
There are commercial products on the market to keep plants warmer, too. The "Wall of Water" is a plastic sleeves with bladders or pockets on it that fits around vegetable plants. You fill the pockets or bladders with tap water, and they act like solar heaters, absorbing the sun's rays by day and giving off gentle heat by night. You need one per plant if you choose to use them.
I made my own solar heaters for the porch where I have seedlings hardening off. I am testing them this year. I used plastic gallon milk containers and washed them out. I fill them with water and allow them to heat up in the sun during the day. Then I place a ring of them around the tender plants in their little pots on the porch. My hope is that the radiant heat from each of the gallon containers keeps the ambient air temperate slightly warmer. The plants are also under the porch roof, so that frost does not settle on the leaves. Hopefully, this will get the hardier perennials through the next few cold nights.
The good news is that the cool temperatures have encourage the tulips to last a long, long time. I love my tulips and the unusual and unseasonable heat meant that I lost some petals from the precocious bloomers, but the usual pastel mix is doing great. Pansies also do just fine during these cold snaps, and my purple and yellow pansies add a jaunty note to the garden.
I wish all my Jewish friends a Blessed Passover, and to all my Christian friends, a blessed Good Friday today as we recall Our Lord's death. Soon to be followed by Easter, the most joyful holiday of the year. If you aren't Christian or Jewish, then my wish is that the spring brings you many flowers, and the Easter bunny brings you much chocolate. I think that covers all bases today.
Have a beautiful day, everyone!