Heating

The UK’s Best Heated Electric Propagators For Seed Germination & Growth

a heated electric propagator in the home

Promote germination and growth of delicate seeds and cuttings in a heated electric propagator, which provides a controlled environment with the ideal temperature, and even humidity and lighting conditions both of which can be fine-tuned. Pamper your precious seedlings – get a propagator!

The heated electric propagator is a heaven-sent for keen gardeners in these cloudy, rainy British Isles. Regardless of cloud, rain, or whatever else, these propagators allow you to get all manner of vegetables, herbs, and even exotic plants going – right on your windowsill.

A propagator comprises of a longish box, usually with separate little containers, be it open trays, closed trays, or pots, inside it. Lids are clear and transparent to allow maximum light and with adjustable vents on the sides or top to control air-flow and humidity. The trick is in the base which is equipped with an electrical heating element. When the unit is plugged in, the base radiates a gentle warmth through to the growing trays. This warmth induces seeds and cuttings to germinate. Not only that, but heat also has an effect on the propagator’s humidity as well.

Heated electric propagators also control the temperature, keeping it within a narrow band regardless of the season; thus, sprouting seedlings are not subjected to large or sudden swings in temperature. For this reason, such propagators let you grow from seeds or cuttings year-round. Heated electric propagators bring several other benefits; see section When Is A Heated Propagator Necessary? underneath to learn about these advantages.

Most propagators are sub-divided into sections in which a number of smaller trays or containers are tidily arranged. Two propagators may be about the same size but one may have two big containers and the other seven small ones. These variables will play a part in how you can use the propagator. In the first type of propagator, you can plant more seeds in each of the bigger containers and you can allow them more time to develop roots but you are restricted to planting only two kinds of varieties, one in each container, as germination times and growth rates vary widely between plant varieties. In the second type of propagator, you can plant as many different varieties as there are containers and transplant each seedling “on its own time” but you can plant only one or two seeds per container and you cannot give them as much time to grow and develop their roots in a protected environment before they must be transplanted.

Our #1 Top Pick
Garland Super7 Electric Heated Windowsill Propagator G51
Value Pick
Garland Fab 4 Electric Heated Propagator, Green, 39x25x16 cm
Also Consider...
Britten & James® Heated Electric Propagator for Plants with Heated Tray and 7 Professional Quality...
Heating Power
13W
10W
13W
Cells
7
4
7
Dimensions
76 x 18 x 15 cm
39 x 25 x 16 cm
76 x 18.5 x 15 cm
Price
£35.27
£19.17
£39.99
Our #1 Top Pick
Garland Super7 Electric Heated Windowsill Propagator G51
Heating Power
13W
Cells
7
Dimensions
76 x 18 x 15 cm
Price
£35.27
Value Pick
Garland Fab 4 Electric Heated Propagator, Green, 39x25x16 cm
Heating Power
10W
Cells
4
Dimensions
39 x 25 x 16 cm
Price
£19.17
Also Consider...
Britten & James® Heated Electric Propagator for Plants with Heated Tray and 7 Professional Quality...
Heating Power
13W
Cells
7
Dimensions
76 x 18.5 x 15 cm
Price
£39.99

Last update on 2020-08-13 / Affiliate links / Images / Pricing from Amazon Product Advertising API

Big, little, and medium – heated electric propagators in various sizes and configurations are run through underneath so you can pick the one that is the best one for your needs.

Best Pick: Garland Super7 Electric Windowsill Propagator

Tried and tested, Garland’s Super7, in spite of the odd quality control defect, lives up to its deserved reputation and delivers consistently happy results.

Garland Super7 propagator is designed for windowsills of usual dimensions as it measures 76 centimetres long and 18.5 centimetres wide. It is 15 centimetres high. The propagator has seven trays inside it, each of which is 7.5 centimetres wide. Trays have clear lids with vents that are adjusted by shifting a bright red slider. Tray and lid together make a ‘mini-propagator.’

The heated base has a 13-watt carbon-fibre heating element which is meant to raise the propagator’s soil temperature to 8° centigrade above ambient.

Quality control is dodgy because sometimes a few trays may not have their drainage holes cleanly punched through requiring you to finish the job or sometimes one or more vents may not be adjustable or a vent slider may have come loose.

There is no on-off switch, the same as with most propagators.

However, this propagator works like a charm; it germinates seeds and cuttings very consistently and reliably, including those of exotic varieties. Moreover, the propagator and its components are strong and solid, and there is next to no flex.

Garland’s Super7 gets strong competition from the Britten & James in this review as the two are very similar in layout, design, and specs. Even though the latter may be better overall, it is a new challenger and is an unknown quantity whereas the Super7 is tried and tested, and can be vouched for.  Therefore, it gets the nod as our Best Pick.

Pros

  • The dimensions and layout are perfect for most windowsills.
  • Consistent and reliable heating of the interior to the right temperature.
  • Tried and tested over many years, it is almost as good as it always was.

Cons

  • Now and again a unit may have some or another minor defect.
  • No on-off switch.
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Value Pick: Garland Fab 4 Heated Propagator

Perfectly defining the term ‘cheap and cheerful,’ Garland’s Fab 4 propagator has a squareish orientation and is an ideal starter set for budget buyers.

Evidently designed by Garland for Beatles fans, the ‘Fab 4’ propagator has a more square’ish and boxy shape than most. The propagator measures 38.5 by 24 centimetres and so is not well suited for most windowsills as sills are usually wide and shallow. It is perfect for smaller but deeper sills, and for placing on a stool or a kitchen counter. The height is 15.5 centimetres.

The propagator contains four trays, each with a vented, clear lid. These ‘mini-propagators’ measure 14 centimetres long by 9 centimetres wide. They are 11.5 centimetres high. They are a cut above those of the Super7.

The trays are perforated with drainage holes. The red sliders for adjustment of the vents are not sufficiently firmly fixed. Sometimes they can become loose and even get detached.

The sealed electric base contains a 10-watt carbon-fibre element designed to raise the propagator’s soil temperature by around 8° centigrade.

There is no on-off switch. But plug it in, and this kit just works. The 10-watt heating element raises the temperature enough to make the world of a difference for germination.

Build quality is very good.

Such a nice little propagator at so cheap a price is undoubtedly a standout value for money and has to be a Value Pick in anyone’s book.

Pros

  • Reliable and consistent heating leading to reliable and consistent results.
  • Mini-propagators are of excellent quality and design.
  • The ultra-low price.

Cons

  • The vent sliders can come loose, and now and then get detached.
  • No on-off switch.
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Britten & James Heated Electric Propagator

An up-and-comer propagator, Britten & James’s kit is as well designed as it is well made; for those who are not swayed by name brands, it may be a best buy.

Britten & James propagator has dimensions of 76 by 18.5 centimetres. It is 15 centimetres high. 

The propagator has seven growing trays with clear lids which have adjustable vents. These ‘mini-propagators’ measure 15 by 8 centimetres. They have drainage holes.

The seven individual ‘mini-propagators’ are virtually identical to those of Garland’s Fab 4 but the arrangement is the same as Garland’s Super7. These ‘mini-propagators’ are better designed than those of the Super7.

The mini-propagators rest on a base tray that is gently heated by a 13-watt heating element that is meant to increase the soil temperature by about 8° centigrade above ambient. 

However, it lacks an on-off switch.

The vents are very easy to adjust; combine this with the fact that this propagator somehow induces more humidity than others, and you have a kit that is a top choice for exotic or tropical varieties. That said, this propagator works very well for all kinds of seeds.

Overall build quality is impressive.

In layout rather similar to the venerable Garland Super7, our Best Pick, this Britten & James propagator is of much more recent vintage. Also, this company is a relative unknown where propagators are concerned. However, we feel it is an up-and-comer model that competes strongly for the Best Pick position.

The electric cord is 133 centimetres.

Pros

  • In arrangement and layout, and quality of the ‘mini-propagators,’ it combines the best features of the Best Pick and Value Pick.
  • The dimensions and layout are perfect for most windowsills.
  • Mini-propagators are of excellent quality and design.

Cons

  • No on-off switch.
  • Not a proven product from a company specialising in propagators.
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Neptune Hydroponics Heated Propagator

Structured on the principle of ‘less is more,’ Neptune Hydroponics set includes a fibre mat and is particularly good at generating and regulating humidity.

Neptune Hydroponics propagator comprises of a large tray inside which (only) two inner trays are fitted. The larger outer tray has a clear plastic lid that has four orange-coloured ventilation sliders which are very well designed and made. 

The whole affair measures 38 x 24 x 19 centimetres. All three trays are made of PVC and the two inner trays have several small drainage holes. The finishing is especially good.

This propagator has 12 watts of heating power so as to maintain internal temperature between 24 and 26° centigrade. In practice, in cool temperatures it will raise the internal temperature to about 6° centigrade above ambient.

It comes with a removable horticultural fibre mat that is meant to be placed in the outer tray for the inner trays to rest on. The mat’s purpose is to retain moisture.

In this propagator you can put some water in the main tray so that it keeps evaporating so as to bring about a humid internal environment. You can adjust the four vents and thereby fine-tune the internal humidity.

Some units do not generate sufficient heat but those that do are extremely effective at propagation; what seeds may or may not be able to do in soil, Neptune Hydroponics’s propagator makes them do within two or three days.

The electric cord is 180 centimetres.

Pros

  • Excellent choice for seedlings that require more humidity or for which humidity needs to be fine-tuned.
  • Excellent choice for planting several seeds of the same variety.
  • Boasts one of the best vents whose sliders are more adjustable and robust than most.

Cons

  • Cannot germinate more than two varieties at the same time.
  • Some units fail to generate sufficient heat.
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Stewart Thermostatic Electric 52cm Large

Unusually well designed to afford maximum mix-and-match flexibility, Stewart’s ‘Large’ 22-watt kit is also well made; it does a fine job in high style.

Stewart’s propagators come in four sizes, ‘Compact,’ ‘Medium,’ ‘Large,’ and ‘Windowsill,’ and in five configurations of which three have heating elements of 8, 22 and 50 watts. Our selection is the ‘Large,’ 52-centimetre size with a ‘rigid crystal styrene’ lid and 22-watt heater.  It is not only very spacious, we feel it is the best overall configuration from among the nearly 20 that are available.

It measures 52 x 42 x 28 centimetres.

The lid has two good-sized vents with adjustable sliders on the top.

A 22-watt heating mat is sealed inside the insulated base. It is designed to maintain soil temperature between 18 and 23 degrees centigrade or 10 to 15 degrees above ambient. Unlike the other propagators reviewed above, this one is thermostatically controlled (non-adjustable fixed thermostat).

This propagator generates low heat; it is not the right choice for those in very cold climates or those who need a really warm propagator. Though the heating element is 22 watts, bear in mind that this is quite a large, spacious propagator. That explained, in typical cool weather, most units maintain temperature at right around 20° centigrade.

The drawback is that the kit has no pilot light so you cannot be sure if it is on or off.

The overall dimensions of the propagator and its ‘high roof’ give ample room for seedlings to mature to a good healthy size in their ‘incubator’ before they must be transplanted. 

The ‘Large’ kit comes with one large internal tray, two small internal trays, and 10 small flower pots. All 13 containers have tiny drainage holes. This smartly-designed set allows you to mix and match trays and pots to suit your growing needs. This is a well-made and robust kit and is particularly attractive. Most importantly, it does the job very well.

It even comes with helpful and interesting instructions.

All said, this set is a really good value for money.

Pros

  • The size and especially the height gives seedlings more time to grow before they must be transplanted.
  • The most smartly-designed of propagator kits so as to permit maximum flexibility.
  • Equally impressive in looks and build quality.

Cons

  • Not a good choice for those in very cold climates.
  • Lacks a pilot light.
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How To Use An Electric Propagator

  • If the propagator has a separate or detachable mat, put it inside the propagator and plug it into an electrical outlet.
  • Put seed compost into the trays (or pots), spray water on it so that it is just damp, and gently pat down the compost by hand or with a small trowel. 
  • Depending on the size of the tray, hand-sow one or more seeds in each tray depending on its size. However, one tray should be sown with seeds of the same variety. Just barely push the seeds into the compost and then sprinkle compost on the seeds so as to merely cover them.
  • Water the tray with a sprayer, being careful not to soak. Put the trays inside the propagator and close the lid. 
  • Water daily per the requirements of the particular seed and variety.
  • Control the air-flow and humidity by adjusting the sliding vents on the top or sides of the lid.
  • Depending on the ambient temperature, you may want to unplug the propagator during some periods of the day.
  • As the seeds sprout and the seedlings grow, you may see the need to unplug the propagator more and more, open the vents more and more, and keep the lid open more and more.
  • Watch for condensation on the ceiling and walls of the propagator to serve as a guide as to the heat being generated and the humidity.
  • After seedlings have two true leaves (not the embryonic or cotyledonous leaves) they can be transplanted into pots or other containers.

When Is A Heated Propagator Necessary?

A heated electric propagator is necessary and also very useful when you want to:–

  • Germinate seeds of exotic plants and those that are native to climes warmer than your own.
  • Accelerate germination and rooting; i.e. what would normally occur in 7 to 10 days, you want to do in 3.
  • Increase the chances of success of germination; i.e. seeds that usually have a success rate of about 50 percent, you want to ‘up’ to, say, 90 percent.
  • Trick seeds and cuttings into thinking it is early summer.
  • Force seeds, cuttings or bulbs to grow early or off-season.
  • Play catch-up and make up for lost time after missing the planting season.
  • Consistently and reliably grow plants like chillies, tomatoes, peppers, squash, peas, melon, broccoli, aubergine, and courgette, which would be hit-and-miss affairs without a heated electric propagator.

About the author

Kersasp 'Kersie' Shekhdar

Kersie learnt the basics of gardening as a toddler, courtesy of his grandfather. In his youth he was an active gardener with a preference for flowering plants. He is a professional and vocational writer and his freelance projects have spanned various kinds of writing.

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