Getting your seeds off to a great start in life is made a lot easier (and quicker) with the help of a heated propagator.
Whether you are looking to germinate seeds early, or have been struggling to get seedlings to thrive, a heated propagator can provide very beneficial surroundings for young plants.
They create an environment that’s just a few degrees above air temperature, creating conditions that help many seeds to germinate. The best part is that they cost just a few pence a day to run.
If you want to buy a heated propagator, the following information should help clear up any doubts or questions you may have:
Choosing the Right Size
The size of propagator you should buy will depend on the space you have available, and how many seeds you want to propagate.
Take a look at the product’s dimensions and match them up with the space you have available – propagators come in a range of sizes, so you’ll find one to fit your space with a bit of searching!
To give an idea of size: there are units that are small enough to fit onto windowsills, whilst others will need to be placed on a table/worktop/greenhouse shelf.
Large, one-cell units that measure around 52 x 45 cm can be used to try to germinate around 140 seeds. They’re often big enough to fit 2 x 24-pot seed trays, and if you get 3 seeds in each pot, this can mean the potential to plant 144 seeds.
Some smaller units have individual ‘cells’ for each pot so you don’t have as much free range with how many different seeds you can plant at a time.
For example, on this page, there is a seven-cell propagator, which would make it possible to plant around 21 seeds (if you planted three seeds in each cell). However, the good thing with individual-cell propagators like this is that you can have better control over the temperature in each cell.
Having an idea about the length of the propagator’s cable before purchasing is also a good plan. Some propagators have short cables of 1 m, whilst others are slightly longer at between 2 and 3 m. Depending on where you have a power outlet, either in the house or greenhouse, you may have to use an extension cable.
Lid Height for Better Growth
The lid height will dictate how long you can keep your produce growing in the propagator – if the plants start pushing the ceiling, they’ll have to be taken out.
Generally, a height of around 20 cm will allow enough space for your seedlings to establish properly, giving them enough time to grow good roots and 3 – 4 full leaves before having to transplant them.
The tallest propagator featured on this page is 28 cm. This sort of height will give a lot of flexibility on the types of seeds and cuttings you can propagate in the unit.
Number of Compartments
The number of compartments will allow you to grow several types of different types of seeds; you can adjust the soil type and environment to suit the individual seed.
Most standard propagators either come with on large seed tray, or one larger tray and a few separate smaller trays. These may be contained under the same roof, or in individual ‘cells’.
If there are separate trays, or there’s enough space to use your own pots, you can have a lot more flexibility on using different soil types and planting different seeds.
Having a propagator with separate ‘cells’ will mean you can choose to ventilate certain cells and not others which allows you to adjust the environment to the individual seed.
For example, on this page, the Garland Super 7 Propagator is one of the best heated electric propagators for catering to different seeds; it has seven different pods and each one has its own ventilation. These type of set up allows you to keep some seeds cooler than others, all whilst using the same propagator.
The Effect on Your Energy Bill
The idea of adding a propagator to your house might seem daunting – doesn’t it cost a lot of money to have a heat source on for a long time?
Electric propagators can range in wattage, and the size of the propagator will also affect how much power you need. The wattage determines the cost of running it.
Generally, you want to be keeping the temperature of the soil inside the propagator at around 10 – 15°C depending on the seed. If there’s no thermostat or temperature control, you can use a thermometer to check the temperature and make sure the propagator isn’t on, using power, unnecessarily.
You can buy propagators that range anywhere from 8 – 100 W.
A propagator of between 13 – 22 W is generally sufficient for home use.
Calculating Running Costs
First, you will need to know how much your energy provider charges per kilowatt-hour. Let’s say they charge 14p per kWh (a relatively standard rate in the UK).
Then, you’ll need to multiply the wattage of the propagator by the number of hours it’ll be used each day. Divide this number by 1000 and multiply by 14 (or your specific kWh rate).
For example, if you run a propagator of 100 W for an hour, at this rate, it will cost you 1.4p for that hour. A propagator of 50 W will cost 0.7p for an hour. And a propagator of 22 W will cost you 0.3 p per hour.
As you can see, at these low wattages, keeping a propagator running is quite affordable.
Plus, if you get a propagator with a thermostat, it will regulate the temperature and save energy by turning off when it reaches a certain temperature.
A lower-wattage propagator will heat up more slowly, but cost less to run, than a higher-wattage unit.
A high-wattage propagator will heat up quickly; however, if there’s no thermostat then you’ll have to be around to turn it off, to stop it from heating unnecessarily and using up too much power.
Back To Contents