What is the Best Type of Greenhouse For My Use? Will I Need to Heat My Greenhouse in the Winter?

What is the best type of Greenhouse for my use? Will I need to heat my greenhouse in the winter?

I am often asked what Greenhouse is best for wintering plants? And my question back has always been two fold; "Where do you live and what type plants are you wintering over?" Your location and type of Greenhouse you have, or plan to get can make a big difference in whether or not you can do what you intend.

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A simple plastic covered greenhouse that is being used in a cold climate area where the night time temperature drops to 40 degrees or less is only good to store dormant perennials that are potted so that any freezing wind won't damage your plants roots and will help warm up the pots in early spring for faster growth and budding. You can add some form of heat to speed up the warmth but it has been my experience that this can be costly as the plastic covering does not hold in heat.

If you want to propagate perennials all winter and store older plants then a greenhouse constructed with polycarbonate glazing is what you need. The polycarbonate glazing will either come in single layer sheets or twin-wall panels (triple wall is also available for harsh climates).

Greenhouses made with polycarbonate sheets will give you the benefits of UV protection, light diffusion and help control condensation but will not perform much better than plastic sheeting covered greenhouses for retaining heat. I recommend investing in a greenhouse made with twin-wall polycarbonate panels. These panels consist of two polycarbonate sheets connected by ribbed channels. This gives the panels the insulating effect of thermo windows allowing you to heat your greenhouse when needed. Twin-wall panels come in different thickness, the greater the measurement the more air space between the panels. The thicker the panel the more insulating properties it will have.

The most common twin-wall panels are, 2mm, 4mm, 6mm, 8 and 10mm. The 8 and 10mm panels are best suited for the colder climates.

4mm and up approx R values:
o 4mm twin wall polycarbonate = R 1.43
o 6mm twin wall polycarbonate = R 1.54
o 8mm twin wall polycarbonate= R 1.61
o 10mm twin wall polycarbonate= R 1.89

So with the twin-wall panels you get the UV protection, light diffusion and condensation control benefits of the single wall panels plus the insulating effect of the panels allowing you to heat your greenhouse during the winter.

Heating your greenhouse can be accomplished with a propane, natural gas, or electric heater depending on the size of the greenhouse and your situation. No matter what type of heat you choose I highly recommend adding good circulation fans so that the heat is distributed evenly through out the area of your greenhouse. Good circulation can reduce heating cost by 5% and prevents mildew and damping off on plants. Ventilation is still important in any greenhouse so keep that in mind, yes even in the winter.

A few rules for a "green" thumb

o Cold Temp of lows in the 40's and below in a greenhouse will help keep off hard freeze of dormant plants.
o Cool Temp of 45 to 50 degrees is good for leafy and root crops that like cooler weather.
o Moderate temp of 55 to 65 degrees are good for propagation, cucumbers, beans, herbs , Ivy and flowers.
o Warm loving plants need temp of 65 to 70 degrees do well. Tomatoes, Peppers, Tropical plants, they also need added growing light if started in winter when sunlight is low and short term, and good heat pads to propagate well. In fact in the winter any plants you are trying to grow, or start will need the added benefits of growing lights and bottom heat to make for healthy roots and strong stalks that are not leggy.
o In the heat of the long summer days you will need to consider the cooling and ventilation needed to keep your greenhouse plants healthy.
o Water and fertilizing is equally important for healthy plants.
o Shade cloth is a good thing to have available for hot days as well.

For those who live in moderate to warm climate the single pane polycarbonate house do a good job in keeping your plants. For those in colder climates, you will have the most success, and happy plants if you invest in a twin-wall polycarbonate paneled greenhouse.

You can purchase the panels and build your own greenhouse or greenhouse kits are widely available on the Internet. When buying a kit, I recommend going to a greenhouse specialty store rather than buying from one of the "big box" chains. Though you may pay a slightly higher price for the kit, the specialty store will usually superior assistance after the sale in case you have problems or questions regarding your new greenhouse.

Greenhouse growing is not hard to learn and having a greenhouse can sure make the long winter days seem shorter and your spirits high.

What is the Best Type of Greenhouse For My Use? Will I Need to Heat My Greenhouse in the Winter?

I am Theresa Saldivia, I have over 30 years of commercial and hobby greenhouse growing and have been an organic grower all my adult life. I have the great pleasure of being the Sales Manager for 4seasongreenhouse.com.

THERMO SPA