Do you grow your own herbs? If so, do you know the difference between a “hot house” and a “cold frame”?
Yes, I do grow many of my own herbs that I use in my products. Last year I started many of my seeds in the house in flats with florescent lights hanging above. In the middle of March my daughter and I made a hotbed at her place and started many more.
This year, I decided to forgo the in-house growing for a hotbed of my own. Because of my lack of physical help, I built up the sides of the hotbed with cribbing (5 inch by 5 inches sq. logs, similar to railroad ties) -which I bought at Laurel Valley Aluminum for $1.00 each; Dean helped me to load them- rather than digging down into the ground. Then my friend Jean and her neighbor Sandy delivered some fresh horse manure, which I spread on the bottom.
I bought 6 bags of potting soil mixture at Cairn’s Agway for $9.99 each and spread this on top of the manure. I adjoined the back of the hotbed to a shed, which gave me southern exposure and only 3 sides to build up. I also bought a big used window (48 x 72) at Laurel Valley for $3.00 and 3 hinges for $1.00 from their ‘junk’ shed. The window needed re-caulked and painted, but it was well worth the price. I hinged the window to the shed wall and built the hotbed to fit it.
Now I was ready to plant. This I did on the weekend of February 9th. As you know, we have had some pretty severe weather since then. I would run out and cover my hotbed on could nights, because I instinctively knew that it wasn’t generating enough heat.
After 4 weeks and not seeing any signs of germination, I did some research- this is what I found: a cold-frame is what I actually built instead of a hotbed and here’s the difference:
● A cold-frame is a protected plant bed, with the temperature difference from inside to outside differing by only 5 to 10 degrees. It is used to provide shelter for perennials, or to start ‘cold-tolerant’ plants such as cabbage. It does not ‘usually’ need any type of heat.
● A hotbed, on the other hand, is a heated cold-frame, used to give an early start to warm-season plants. It is in essence a mini-greenhouse.
Basically, the hotbed or cold frame is a rectangular box with the back higher than the front, covered with a transparent roof. The slope from back to front should be 1 inch per foot. Both should face toward the south, running east to west. Okay- so far, so good. For a hotbed that is to get its heat from fresh manure, one should dig down into the ground 14 inches and place at least 18 inches of manure on top of some gravel for drainage. You should also let the soil warm up before planting, which I didn’t do. I didn’t dig down and my manure was only 6 inches deep. I didn’t put down gravel and I didn’t let the soil warm up before planting. I realized my mistake when I didn’t see condensation on the glass on sunny days. This was a good indication that there wasn’t enough heat on the inside of the frame.
I have since learned that if you don’t have access to fresh manure, you can use a heat tape or electric coil. This should be placed beneath the soil in a squiggly fashion. I’ve also heard that you can use small votive candles inside the frame- use one candle for every 2 square foot of space. I opted not to do this, because I’m afraid of starting a fire. Whatever type of heat you go with, it’s important to make your hotbed air tight, checking for any leaks where the warm air could escape. I like to use sod or old insulation for this purpose. I also anchored down the front corners with a big rock, just to make sure it was a tight fit.
Am I worried that my seeds won’t sprout? Yes and no. Yes, because I know that there’s not enough heat in the hotbed now and no, because many seeds need the cold/warm process to sprout effectively and pretty soon the days will be warmer and the nights less frigid. I continue to remain hopeful that they’ll sprout. And if they don’t- well, I have plenty more seeds!
Have I learned a lesson? For sure! Next year, I’ll definitely dig down, put at least 18 inches of fresh manure on top of a layer of gravel and let the soil warm up before planting.
As I see it, all of life is a learning process and we’re never too old to learn!
