6 Ways to Keep your Greenhouse Warm in Winter

Don’t let outdoor plants freeze this winter – keep them alive indoors. Last week we explained how to do it in a loft. Here’s how to do it for a low cost in your greenhouse.

First insulate your greenhouse. All you need is bubble wrap. The bigger the bubbles, the better the insulation.

Cover all windows and doors to stop heat escaping. Once you’ve done this, heaters won’t have to be on for as long to keep your greenhouse warm. This really reduces heating costs.

A Grow Gadget heater is great in greenhouses. You don’t have to wait for it to warm up – it heats as soon as you switch it on. You’ll hardly ever need it on, so running costs stay low.

Make sure you monitor your temperature using a thermostat - AirComforts are big sellers!

You can then adjust your heating times to keep your temperature inside the right range. Place any probes or thermometers at plant level for accuracy. Ideally, you should aim for a temperature of 24oC - 28oC (lights on).

Just using a heater isn’t enough - you need to make sure the air in your grow room is being warmed evenly. Otherwise, you’ll get cold and hot patches.

To make matters worse, when this happens, you can get inaccurate temperature readings (depending on where your probe is placed).

The solution is simple - you just need to keep the air in your greenhouse well mixed. That’s where air circulators come into their own.

The KlimaHeat has an ‘air circulation’ function that mixes air. Or you can dot around some air circulator fans. They don’t cost much to buy, but help you keep your climate spot on.

Plants use CO2, but release oxygen and moisture. Unless you ventilate, you will end up growing plants in a humid, CO2 depleted environment. Mould, mildew & fungus can become a threat.

So it’s important that you keep your greenhouse well ventilated.

Just open your greenhouse vents periodically to freshen the air. Remember to close them during the night to keep plants warm.

There are lots of ways to do this. You can turn Flexi Work Trays upside down and place pots on these. Or you can put a layer of clay pebbles at the bottom of pots. Here you can see plants being elevated in an NFT system.