A heated propagator produces a microclimate of steady warmth and humidity. This encourages seeds to germinate quickly and reliably, and cuttings to root very easily.

You could sow exotic seeds like morning glory or canna or the climbing glory lily.

heated propagator

Canna 'Golden Gate' in the Berggarten botanical garden in Herrenhausen near Hanover, Germany. © Michael Gäbler and reused under https://creativecommons.org/licenses/by/3.0/ Canna seed will germinate in a heated propagator.

You could sow cosmos, kale, tomatoes, sweet peas and salvias in February or dahlias and summer bedding in March and April.

You could root streptocarpus or campanula cuttings. Or start off begonia tubers.

What does a heated propagator look like?

Different styles of heated propagator, some with thermostats, are available. Perhaps the most common used by amateur gardeners is about the size of a standard seed tray with a transparent and ventilated lid.

The base contains an electrical element which distributes heat evenly.

The ventilated cover ensures good air flow reducing the risk of fungal diseases.

heated propagator

X Stream Heat propagator © Nutriculture. Thanks to Home Garden Labs.

Where to put the propagator and what to do

You’ll need somewhere with an electric socket.

Bear in mind that the propagator lid (however clean) cuts down some light, so locate the unit in good natural light for cuttings to grow. Possibilities are a greenhouse, bright shed, garden room or bright window sill.

heated propagator.

Streptocarpus. © Graeme Churchard and reused under https://creativecommons.org/licenses/by/2.0/
It's easy to root streptocarpus cuttings in a heated propagator.

Place your seed tray or pots in the unit and make sure the ventilation slots are open. Make sure you've switched it on! Check the unit daily and water sparingly. Take the lid off to air for half an hour every day, and wipe off excess moisture. Clean the unit before using it for another batch of seeds or plants.

Once seeds have germinated take them out of the propagator (or switch it off). If you don’t, they will get too hot and will die. Put them somewhere with plenty of natural light so they grow into strong and sturdy plants. Depending on the plant, grow them on slowly in cooler conditions (perhaps another window sill with no heat or an unheated greenhouse).

Warning! It’s so tempting to sow lots of seeds early when you’ve got a heated propagator but remember to ensure that you have a place for them to go next. It might still be too cold outside! It can be best to hang fire for a week or so if the time isn't quite right yet.

I wouldn’t be without my heated propagator. It’s a great and relatively inexpensive tool for the amateur gardener.