plant heaters indoor

Feel the heat: keeping plants warm indoors during winter

With winter on its way the house is beginning to clog up with plants seeking a warm spot to see them through until next spring. In years gone by my windowsills and shelves were like death rows for pot plants as they perished in turn due to lack of proper care and attention. This was partly due to watering neglect, but mainly due to lack of consistent light and, more importantly, consistent warmth. Although those windowsills ramped up the heat during the day, at night the cold drafts snuck in through the dodgy frames and the temperature plummeted.

Now my plants stand a better chance of survival. A few years ago I moved to a new home, which has a conservatory with two radiators separately plumbed to the heating unit, allowing me to give the room a warming boost without paying to heat the rest of the house. The plants love it so it’s just the ‘neglect’ part I now have to take care of.

I appreciate that me and my garden exiles are lucky, and not everyone
lives in a home with a curiously beneficial plumbing set-up. Thankfully there are numerous gardening tools and devices that do the job, along with a few DIY options, so here are five suggestions for ways to provide steady warmth for those in-bound plants…

1 Bubble wrap

One of the cheapest and easiest way to provide some snug warmth for overwintering plants is to dress them up in bubble wrap. The temperature will still vary according to the temperature of the room they’re in but that extra layer of bubbles will help insulate against colder snaps.
Try this: Roll of bubble wrap from Amazon

2 Electric white goods

If you’ve got a fridge or freezer in a place that gets natural light you could simply place your plants on top of it. It takes a fair bit of power to keep your ice-pops frozen and, in doing so, some gentle warmth will escape. Just be careful watering around electrical goods and try not to spill soil over your oven chips.

3 Programmable radiators

For the ultimate plant (and human) luxury, consider a programmable electric radiator that can heat a single room without wasting energy on the rest of the house. They offer maximum control and can automatically adjust to sudden changes in room temperature. And there’s no need to rip up the plumbing.
Try these: Electric radiators from VeriSmart Heating

4 Heat mats

I have been known to rest my shivering plants on the top of an old brewing heat mat, designed to keep booze fermenting at a constant temperature. Far more reliable than this approach is to use heat mats designed for the task.
Try these: Hobby Heatwave Propagation Mats from Gardens4Less

5 Heat lamps

Instead of heating from below, you could try heating from above with foliage friendly heat lamps. Not only will they given your plants a suitably warm glow, LED bulbs also provide some beneficial light.
Try these: Tesler lights from Lamps Plus

6 Electric Propagator

Since first writing this piece I have invested in an electric propagator and it’s plugged in every February, bringing me great success. Ideal for windowsills it’s essentially a tray, lined with a heat mat and covered with a clear lid. You can also use individual lidded trays and sit them on the mat to soak up the heat. Perfect.
Try this: Electric propagator from Amazon

With cold weather looming there's a garden exodus underway. Here are five tips for keeping plants warm indoors during winter…

7 Practical Heating Solutions for Your Indoor Grow

Takeaway: Heating your indoor grow can be a problem, but it’s a problem with some practical solutions

It’s a challenge keeping your leafy friends warm in winter when cold air finds its way through every nook and cranny. Shannon McKee offers some options to keep your plants cozy until the warmer months arrive.

Winter is in full swing, and you may be noticing that your grow room is just a tad too cold for your plants. It may be time to look into adding a heating source. No matter if your grow room is set up in an outdoor hoop house, greenhouse, or your basement, there are heating solutions that will work to keep your plants at a pleasant temperature that will keep you growing all season long.

Soil Mats

One of the first options available for heating your growroom is focusing on heating the soil rather than the air. Soil or seedling mats sit underneath your trays and pots to provide the warmth that growing plants need. These soil mats are a great option when you want that ideal soil temperature between 75-85°F but can’t imagine trying to keep the heat in your home or greenhouse at that temperature. Some people only think of this as a germination mat, but it’s valuable for heating plants that have already germinated.

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Heat Lamps

Another option is heat lamps, but depending on your set-up, this may not be an ideal solution. Some people may opt for heat lamps rather than heated soil mats, but this can sometimes backfire. Depending on where you have it located in your set-up and how long it’s left on, the heat lamp can dry out your plants and result in burns to your foliage. When using a heat lamp, you’ll want to keep it on just for a short period of time and ensure that you’re checking the moisture levels of your soil. There’s a good chance that you’ll need to water regularly to keep the dirt moist.

Compost Generated Heat

It may sound crazy, but you can use compost to warm your plants. This option is one way to create a heat sink and is excellent for greenhouses and hoop houses. You can dig a trench inside of your greenhouse, and cover it with a type of removable walkway so it’s not a problem.

This compost will heat up thanks to your daytime temperatures and will release this heat later in the day. Plus, you’ll get the bonus of having all that black gold ready to add to your garden. Just keep in mind you’ll have to carefully consider where you’re going to put that mainly open compost pile.

Water Storage

Another heat sink idea is to store water around your greenhouse or hoop house. You want the water storage to be placed in an area where it can be heated by the sunlight during the day. Then, during the night, the heat energy will be released into the surrounding area as the water cools off.

This option offers the benefit of having water on hand for your garden, but you have to make sure that you add the water back in as you siphon it off. Removing the water means that you’re eliminating heat storage space.

A good starting place for this method is a 55-gallon barrel, but you can use whatever water storage containers you have handy. To help get the most heat absorption, use dark materials for your tanks.

Electric Room Heaters

A popular option is an electrical room heater. There are some horticultural options that are made explicitly for greenhouse heating, but others do use regular room heaters. This type of heater means that you’ll need either an extension cord or outlets in the area where you plan on using the heater. Keep in mind that you have to use these types of heaters appropriately; you don’t want to create a fire hazard because your heater was too close to flammable materials.


One thing that you need to keep in mind when using any of these heat sources is to circulate the heated air throughout your space. You don’t want hot and cold spots popping up in your greenhouse. Plus, this helps with the condensation that can happen when heating an area in which you’re watering or growing plants hydroponically. Some heaters will have a circulation method, such as a fan, built in, but you’ll have to determine if you need additional circulation for your set-up.


While insulation is a passive heater, it can make your efforts more worthwhile. Insulation may not be appropriate in every situation—like covering up greenhouse windows for insulation, as you’ll then be blocking the sunlight from coming in—but there are other areas where adding some insulation can come in handy. Gardeners that grow in basement areas or different rooms inside of their homes may find that merely adding insulation goes a long way towards keeping the chill out of the room and the heat inside.

The temperature that you need in your growroom is going to depend on what you’re growing and your current set-up. Once you determine what temperature you need to try to reach, you’ll be able to personalize your heating plan based on your needs. You may find that you need to mix and match some of these options to get the right level of heat in your growroom.

It’s a challenge keeping your leafy friends warm in winter when cold air finds its way through every nook and cranny. Shannon McKee offers some options to keep your plants cozy until the warmer months arrive.Winter is in…