Garden & Lawn

6 Best Propagators For Seedlings – Heated, non-heated and self-watering propagators

Last updated on February 26th, 2022

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I have used many propagators over the years, from the standard tray propagators with no heat to the more professional large heated propagators from Hotbox. This was an amazing propagator but at over £500, it isn’t really what most home gardeners are going to be looking for.

Small heated propagator, easy to use and very energy efficient

In this review, I have focused on the smaller, domestic use propagators. These propagators can be unheated or heated (also known as electric propagators) but models some take it a step further and have thermostats whilst some even have variable heat control.

To be clear, the difference between a thermostatic propagator and a variable heat propagator is that a thermostat propagator usually maintains a certain temperature above ambient, usually 10-15 degrees so this would give you an average soil temperature at 18-23 degrees Celsius. Whereas a variable propagator would give you the option to increase or decrease the temperature, usually between around 12 and 28 degrees Celsius.

So the propagator I now use the most (as pictured above) is the Garland Super7 Heated Propagator. I have found it to keep a consistent temperature that generally gives me an even germination rate. However, what I really like about this propagator is that it fits perfectly onto the windowsill in my kitchen, and on top of this it has 7 individual seed trays, each with airflow control. This means I can easily sow 7 different types of seeds at the same time. If I recommend any model to friends and family, this is usually the one I recommend.

BEST PICK

Garland Super7 Heated Propagator
With so many propagators on the market it can be difficult to decide which one to try. What I can tell you is that I still use the Garland Super7 Electric Propagator every year even though I have more expensives alturatives. I feel like this heated propagator is perfect for anyone who wants to use a propagator inside the home or conservatory as many people do including myself. Its might not have a thermostat or variable control but it maintains a reasonable constant tempature of around 26c for me or around 8C above ambient temperature which ideally should be at least 10C. To give you an idea, I have propagated chilli plants, tomatoes, pansies, poppies, aqualegias just to name a few and they genenated faster and maybe more importantly for me, evenly than using a standard unheated propagator. Finally, I love that it has 7 individual seeds each with its own clear lid and vents so its perfect for sowing different types of seeds at the same time and I even have a spare set of trays so I can start sowing the next lot of seeds when I take the other germinated seeds off heat to stop them getting too leggy. Finally it fits perfectly on a window, its to wide with is a isue with many other models. Overall I feel this is probably one of the best propagators for using at home on the window or even in a heated greenhouse.

Runner-up

Stewart Variable Control Electric Propagator
This premium propagator can be used anywhere, from your greenhouse, conservatory or on a window if its large enough, take note is fairly big and doesnt fit on my windowsill. You choose what temperature you want the soil tempature to be from the range 12°C - 28°C which is easy to adjust using a small dial on the tempaure control unit. You them plave the probe into the soil inside the propagator. I find that the 50W heating element keeps the temperature constant at that point. This compact propagator comes with a clear lid letting in maximum light and allowing you some more control over the temperature along with the humidity by adjusting the vent there. This propagator is an investment for its top-of-the-line features if your looking for a model that is a little more advanced. Its also useful because you can use individual pots which are included as well as the included seed trays. If your looking to give yourself a little more control over your seedling, if your propagting something a little tropical for example, this is well wirth considering, its also great for keeping in a greenhouse too.

The 6 Best Propagators we have reviewed and included in this guide

  1. Garland Super7 Heated Propagator MY BEST PICK
  2. Stewart 52cm Propagator With Adjustable Thermostat – RUNNER-UP
  3. EarlyGrow 24″ x 15″ x 16.75″ Domed Propagator Great for growing on taller seedling for longer
  4. Super 7 Self-watering Propagator
  5. Garland 24 Cell Self-watering Propagator
  6. Garland British Made Big 3 Electric Propagator

1. Garland Super7 Heated Propagator

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BEST PICK

My Garland Super7 Heated Propagator Review

The Garland Super7 Electric Propagator is my favourite propagator. It is the one I always seem to have something growing in. So, there is a lot of talk about how thermostatic propagators are better as they maintain a certain temperature and variable models where you can adjust the temperature to be very specific. However, the truth is, for 99% of gardeners are those at home looking to propagate a few seeds (me included) and don’t really need any of this, it would probably just be a waste of money.

Don’t get me wrong, for some people, these extra premium features are useful but I’m just saying, the majority of people can get by with a standard electric propagator that provides bottom heat, as we use to call it in the trade.

Garland propagator from right side view on my windowsill

What do I like so much about this model? Firstly, it’s still heated and warms the compost evenly by about 8°C above ambient temperature, so for me, it can maintain a temperature of around 20-26°c in my kitchen. This is perfect for germinating most types of seeds.

Super7 propagator with different types of seeds which have germinated

I have sown everything from winter pansies, tomatoes, peppers and other vegetables, sweets peas, perennial seeds including one of my favourites Aquilegia Magpie. This heated propagator has a 13-watt carbon fibre element that warms the compost, which is how it is able to do this whilst still being very energy efficient. Not to mention it is also one of the more affordable heated propagators.

Heated propagator fits perfectly onto a standard size windowsill

Another feature that I personally like with this propagator is its actual dimensions. It is a long yet slim model (76cm long by 18.5cm wide) making it the perfect size to sit comfortably on my windowsill. I often start seeds off on my kitchen windowsill like many of you probably do, and it fits on there perfectly with no overhang. If you want to compare, my window is only 21cm deep so it leaves a little space both in front and behind the propagator.

Cosmos germinating in only 2 days
Cosmos germinating in only 2 days
Cosmos been grown in quarter seed trays in heated propagator
Cosmos a couple of weeks later

What I’m trying to point out is that most people have a standard-sized windowsill in the kitchen and this propagator should fit on there nicely, unlike most other models that are too wide and they would hang over the edge of a standard windowsill.

Close up of the Garland Super7 After sowing some seeds and covering with  vermiculite and leaving on the windowsill

Now, the next thing I really like is that it has 7 individual seed trays, each with its own clear lid. This is perfect as I can easily sow at least 7 different types of seeds at the same time. I even have a spare set of trays so I can take off any trays that have germinated to help prevent them getting to leggy and sow the next lot and put them onto the propagator whilst the other trays can be placed elsewhere to grow on without bottom heat.

Some pansies and aquilegias ready to prick out, the last of the last batch of seeds i have sown and grown on

The trays themselves are quite small compared to a standard seed tray but at around 17cm x 10cm you can still sow plenty of seeds in them. I usually find I sow too many anyway, especially when I am sowing seeds into full-sized trays.

Close up of the air vents on the Garland Super7 to improve air circulation to prevent damping off and control the inside temperature more

Finally, in terms of build quality, I have no complaints. It seems to be as well built like most other models, the lids seem to be shatterproof. Each lid has their own vent so you control the environment (including ventilation and humidity) within each mini-propagator separately. Most other propagators you cannot do this with as they have one large lid over the whole of the propagator.

Pros

  • Warms the compost evenly by about 8°C above ambient temperature, so for me, it can maintain a temperature of around 20-26°c in my kitchen.
  • The base tray holds seven individual seed trays so you can sow seven different varieties of seed if you wish.
  • Crystal clear lids are shatterproof and let in the maximum amount of sunshine.
  • Vent in the lid of each mini-propagator lets you set the environment for each type of seedling individually.

My conclusion

I really like the Garland Super7 heated propagator. It’s affordable, easily fits onto my kitchen windowsill and maintains a consistent tempture well, which in turn, leads to a good germination rate when sowing seeds.

As mentioned, this is my propagator of choice, it is just so easy to use, no messing around with variable heat settings or temperature probes, switch it on and its ready to use. Below are some winter pansies I have sown in the propagator and are ready for pricking out. I have grown a good mix of seeds now and have not had any issues with getting them to germinate.

Pricking out 5 different varieties of Pansy germinated in the Garland Super7 Propagator

If you are looking for a good heated propagator to use at home, this is what I would recommend. The only downside is you can’t really put pots into the individual seed tray with the lids on. However, should you wish to, you can still put pots onto the propagator instead of the seed trays and then put a clear bag over the pots if needbe. For me, I just sow everything in trays and then prick them out into small pots or trays with individual cells to grow them on.


2. Stewart 52cm Propagator With Adjustable Thermostat

Runner-up

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stewart essentials propagator review

The Stewart 52cm Propagator With Adjustable Thermostat has the same quality, durable construction and crystal styrene clear cover we’ve come to expect from this brand. The clear cover provides optimal clarity and maximum light transmission for a better germination rate. Air vents on the top of the cover control humidity and air temperature.

The adjustable thermostat allows you to set the temperature anywhere between 12 and 28 degrees Celsius using the dial. The 50W heater is more powerful than the heater found on most other heated propagators. This is ideal for plants that require a specific temperature to germinate.

Included in your purchase is a handheld temperature probe so you can directly check the temperature of the soil in the pots and make any temperature adjustments necessary.

You can use this model anywhere, from a windowsill in your home to a shelf outdoors in your greenhouse.

Pros

  • Adjustable temperature propagator with a range between 12o-28o C to suit whatever temperature your seeds germinate best at.
  • Heater is 50W to provide the right amount of heat for germination.
  • Clear styrene cover lets in the maximum amount of light for your seedling’s best growth.
  • The temperature dial is easy to access; just turn it to set the correct temperature.
  • Air vents in the lid open and close easily as an additional control for the temperature and humidity.
  • Temperature probe (included) lets you check the temperature of the soil in the pots directly to make sure that the plants are in their optimal environment.
  • Comes with one large seed tray, two small seed trays and ten flower pots.

Our conclusion

The Stewart 52cm Propagator With Adjustable Thermostat is our recommendation if you are a gardening enthusiast and experienced gardener. If you sow a variety of plants, the adjustable temperature gives each variety of seed the best temperature to start their growth. And you can check the temperature of the soil in each container with the handheld probe to ease your worries about whether the seeds are in the right environment for their best growth.

The only downside is the price, as it is more expensive than a non-adjustable thermostat propagator and more than double the price of a standard heated propagator. That being said, this is a premium propagator and worth the investment.

The Stewart 52cm Propagator With Adjustable Thermostat is our choice for Best Pick of the propagators in our review. This propagator makes it easy to give your seeds the best environment for the first phases of their lives and takes the worry out of doing so.


3. EarlyGrow 24″ x 15″ x 16.75″ Domed Propagator with 3 Height Extenders and Locking Clip Set

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EarlyGrow 24

The EarlyGrow 24″ x 15″ x 16.75″ Domed Propagator with 3 Height Extenders and Locking Clip Set is neither heated nor self-watering. But that does not mean that it’s just a simple propagator. This is a model to consider seriously if you plan on starting many plants out from seeds or if many of your seedlings are going to grow really tall.

From its title above, this EarlyGrow propagator has a tray that’s 60cm by 37.5cm. That’s a significant growing space for starting your seeds out. The tray is made from heavy-duty plastic that’s strong enough to carry pots of fully grown plants without bending or becoming wonky. The clear lid is also made of strong plastic that won’t become brittle if you use grow lights above it. Two vents in the lid let you change the temperature and humidity inside the unit by letting air in.

But the really unique feature of this propagator is that you can extend the headroom between the tray and the lid – a lot. Your purchase comes with three height extenders and more are available at an extra cost. As your plants get taller, clip-on a height adjuster for an extra 12.5cm or so of vertical space for them to grow into.  Using all three extenders gives you 37.5cm of headroom.

The extenders clip to each other and to the lid, forming one piece. This makes it easy to remove the entire cover to get into the propagator to look after your plants. Each height extender is made of clear plastic and has a vent on the side. This is because your plants need more ventilation as they grow.

Pros

  • Extendable propagator with a heavy-duty tray so you can safely carry heavy pots without the unit bending or buckling.
  • Height extensions let you add headroom as your plants get taller.
  • The clear lid has two vents to open or close to control the temperature and humidity inside as your plants need.
  • Height extensions have their own side vents for further control of the interior climate as your plants get bigger and taller.
  • Height extensions lock into place and to the lid and can be removed in one piece when you want to water or tend to the plants inside.
  • The extra-large tray holds 60 5cm x 5cm seed planting cells so you can germinate a lot of seeds at once.

Cons

  • Not heated.
  • Not self-watering.

Our conclusion

The EarlyGrow Domed Propagator with 3 Height Extenders may not have the features of a heated or a self-watering propagator, but it does extra-large growing space and vertical height. Germinate all your seeds at the same time and then add on the extensions as the taller plants take off. The clear lid can handle any grow lights that you use for light and warmth – you just have to remember the watering schedule.

We recommend the EarlyGrow Domed Propagator with 3 Height Extenders for anyone who starts tall plants from seed or loves to have their seedlings really established before transplanting. It’s the Runner-up in our review of the Best Propagators.


4. Garland Super 7 Self-watering Propagator

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super7 propagator review

Not to be mistaken for the Garland Super7 Heated Propagator we reviewed previously, this Super 7 Self-watering Propagator is for those who would rather automatically provide water than heat to their germinating seeds and subsequent seedlings. This is an unheated propagator so do make sure that your windowsill or wherever you place it is warm enough to encourage the seeds to start growing.

This self-watering propagator has a built-in self-watering feature to keep the soil moist. It works by having an outer water reservoir tray that stores water and in which sit some capillary matting which picks up the water. The seven mini seed trays then sit on top of the capillary matting that retains the water and then the compost and plants take up the water using capillary action as and when needed. As long as you make sure the tray always has water in it, the plants take what they need and won’t be under or over-watered.

The green containers and their clear covers are built from strong injection moulded plastic that makes them rigid and shatter-resistant. You control the interior temperature and humidity of each container by adjusting its individual vent at the top of the cover.

Pros

  • Self-watering propagator for those who aren’t so good at remembering watering schedules.
  • Seven mini propagators sit in a single tray to keep them organised and tidy.
  • Individual vents on the lid of each propagator let you control the temperature and humidity of each one separately.
  • The container and lid are made of shatterproof plastic for strength and safety.
  • Grow a different type of seed in each propagator for maximum variety.

Cons

  • Not heated.

Our conclusion

The Garland Super 7 Self-watering Propagator is for those who already have a warm enough spot in their homes that doesn’t require a heated propagator. You can now release the task of watering your seeds to the propagator. The slim design means it fits onto a windowsill easily, making it very appealing. The seven mini trays are ideal if you grow a variety of plants as they can be sown separately and each has its own environment.

We recommend the Garland Super 7 Self-watering Propagator for those who don’t need a heated propagator and who don’t want to remember to check their variety of budding plants for water every day.


5. Garland 24 Cell Self-watering Propagator

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Garland self watering propagator review

This Garland 24 Cell Self-watering Propagator has 24 cells and is a very budget-friendly choice. Although it is not heated, it is self-watering, taking one daily worry away from your spring garden preparation tasks.

This model has an internal water reservoir and on top of this, there is a lining of capillary matting that attracts the water. The seed tray sits on top of this and the plants then draw water from the capillary matting as and when needed. As long as there is water in the tray, the plants can’t over or underwater themselves.

For the eco-conscious gardener, this unit is made from recycled plastic and is designed to be reused. It’s not the strongest plastic but will probably last a few years if you aren’t too hard on it.

Pros

  • A self-watering propagator that has 24 individual cells so the seedlings won’t bother each other.
  • Internal water reservoir with capillary matting that takes water up to the plant so you don’t have to.
  • Tray and cover made from recycled plastic for the eco-conscious gardener.
  • Slim design that fits comfortably on a sunny windowsill or shelf.

Cons

  • Indoor use only.
  • Not heated.

Our conclusion

The Garland 24 Cell Self-watering Propagator is an unheated propagator that’s a step above the slightly less expensive regular 24-cell plastic propagator. But for the few extra pounds, you don’t have to constantly worry about your compost getting too dry or becoming over-watered. Just make sure that the windowsill or shelf that you place this on really does receive enough warmth and sunshine to let the seeds germinate and the seedlings grow strong.

We recommend the Garland 24 Cell Self-watering Propagator for anyone who wants just a basic propagator tray and who has a habit of over-watering or forgetting to water their plants.

6. Garland British Made Big 3 Electric Propagator

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GARLAND BRITISH MADE BIG 3 ELECTRIC PROPAGATOR

The Garland British Made Big 3 Electric Propagator provides an extra-large growing space divided into three separate full-size propagators, each with its own cover. All three propagators share a single tray that keeps them together and organised.

This Garland propagator is thermostatically controlled and heated by a 50w heating unit. Each propagator is kept at a constant 19°C to ensure the best growing temperature for your seeds, seedlings and plants.

You can override this by opening the vent on top of each propagator to change its interior temperature and to affect the humidity. Effectively, each propagator can have its own environment to suit whatever variety of seeds you are growing.

As well as having more growing space than usual, you also have more headroom with this Garland model. The high-top covers give you more vertical space so feel free to grow taller plants or leave your seedlings in there for a little longer if the weather outside is not suitable yet for transplanting them.

If you’re planning on putting this propagator on a windowsill or a small shelf, check the dimensions beforehand as this model is indeed extra large.

Pros

  • Single temperature propagator maintains the temperature at a constant 19°C for an optimal environment for your seedlings.
  • Heater provides 50W of power to this extra-large, shatterproof propagator.
  • Three large propagators sit in a single tray to provide a variety of large growing environments.
  • High-top clear covers provide extra headroom for taller plants and seedlings.
  • Single vent in each cover lets you adjust the humidity and heat in the propagator.

Our conclusion

The Garland British Made Big 3 Electric Propagator provides plenty of space for those who are serious about starting all their annual flowers and vegetables from scratch. This heated propagator holds the three individual units thermostatically to a constant temperature of 19°C that seems to suit most plants. Let your tomatoes grow a little taller than usual within the extra tall covers to ensure they’re really ready for transplanting.

We recommend the Garland British Made Big 3 Electric Propagator for serious gardeners who want to be there from the very beginning of their plants’ lives.


Buyer’s Guide

Knowing the entire life story of the plants in your garden is possible if you use a propagator to start them from seeds. You only need to make a few decisions when choosing the best propagator for your style of gardening and what seedlings you’re aiming for. Here’s what you need to know.

Why use a propagator?

Propagators can be used to help cuttings strike and take root, but they are most commonly used to aid the germination of seeds. By using a propagator you can control the seed’s initial growing environment and get a better success rate of germination and strong seedlings

types of propagator

Types of seed propagators

Germinating seeds and growing seedlings needs these elements: heat, light, nutrients and water. Whichever of these your propagator and growing medium doesn’t provide, you must.

Basic

A basic propagator consists of a seed tray and a transparent clear lid. They are simple to use and help to retain moisture, which stops the seeds and seedlings from drying out. They also keep the air inside slightly warmer than the outside environment.

Heated – no thermostat

Heated propagator with no thermostat or variable heat

These provide a consistent temperature that is pre-set by the manufacturer. The heat is usually constantly on and cannot be turned off. These are ideal for lots of seeds but are may not suitable if you are growing different types of seeds that will germinate at different temperatures. The pre-set temperature made by a set temperature (e.g. 19°C) or maybe a temperature difference (e.g +5°C over the ambient temperature).

Heated – with thermostat

Often regarded as the holy grail of propagators, these are heated propagators that come with a thermostat that you can set to within a range of temperatures. Set this to your required temperature, usually between 5°C and 30°C, so the environment is perfect for the type of seed you’re growing. These work by regulating the temperature to within 1°C.

Self-watering

These propagators have a water reservoir that wicks water up to the plants (and potting medium) through capillary action via a capillary mat). The plants determine how much water they need and when they need it. These propagators are ideal if you have a habit of under or over watering plants. You just have to ensure that the water tray or reservoir doesn’t run dry.

Size

Small propagator growing perennial seeds

Be realistic about how many seeds you want to germinate and plant more than that in case some don’t come up. Also, check the dimensions of the propagator before you buy it. Some have a slim design that fits on a windowsill and others are determinedly extra large and need a dedicated growing table.

Think also of the size the seedlings need to grow to before you can transplant them. Some may grow to be quite tall, and so look for propagators with extra headroom.

Inside/outside

Not all propagators are suitable for use outside in your greenhouse, though all can be used inside your home. Assume that the propagator can’t be taken outside unless the information of its box tells you otherwise.

Alternate heat and light source

If you really need a self-watering propagator or your budget doesn’t stretch to a heated unit, consider an alternate form of heat and light. In the UK, if you don’t have a sunny and warm enough windowsill to germinate your seeds then you may need to consider a grow lamp, perhaps one on a timer so you don’t have to remember to put it on and off on the right schedule.

You could even try a Smart garden, an item I have also reviewed here


FAQs

What are the basics of using a heated propagator?

  • Ensure that you plant the seeds carefully using clean equipment to avoid contaminating the growth environment. The seeds have to be in touch with the compost to optimise maximum growth.
  • Set the temperature that is required to promote plant growth if your heated propagator has a thermostat.
  • Place the seed propagator somewhere with good natural light to promote the growth of cuttings.
  • Avoid lifting the lid unnecessarily as this will disturb the temperature and humidity levels inside the propagator.
  • If there is too much condensation, make use of the vents to release excessive moisture.
  • Ensure you water your seedlings but do not flood the seedlings as the water may affect the electric circuit of the propagator.

Do you water seeds in a propagator?

Yes, you can water seeds in a propagator but the aim is not to flood the seeds. It is advisable to soak the seed pots in a shallow tray to permit the compost to get wet. Once the compost is wet the seeds can get moisture from the compost without exposing the seeds to too much moisture or compromising the electrical components.

Do I need a heated propagator?

This depends on the plants you are trying to grow and the region that you are in. Some seeds require certain temperatures to germinate. Given the cold British weather, a heated propagator would be of service to you all year-round and can speed up the amount of time it takes for seeds to germinate and also the success rate. For example, peppers often germinate at a much faster rate in a heated propagator.


Final Conclusion

Having the ability to control and manage your plant’s growth environment is empowering. Whether you want to grow chillies, tomatoes or any herbs, you can rely on your propagator to provide a secure environment.

Just ensure that you read the instructions on both your seed packet and propagator to ensure you have everything in order. After that, you can rest easy knowing that soon you will have healthy seedlings in your hands, ready for a transplant.

My best pick

If you’ve bought your propagator but are not sure where to go from there, I can help. Read My How to Grow Perennials from Seed and my How to Grow Bedding Plants from Seed articles.

And, of course, everyone needs to try growing Tomato Plants from Seed.


Last update on 2022-03-17 / Affiliate links / Images from Amazon Product Advertising API

Welcome to my site, my name is John and I have been lucky enough to work in horticultural nurseries for over 15 years in the UK. As the founder and editor as well as researcher, I have a City & Guilds Horticultural Qualifications which I proudly display on our About us page. I now work full time on this website where I review the very best gardening products and tools and write reliable gardening guides. Behind this site is an actual real person who has worked and has experience with the types of products we review as well as years of knowledge on the topics we cover from actual experience. You can reach out to me at john@pyracantha.co.uk

2 Comments

  1. David SHEMILT

    Are these units available in Victoria AUSTRALIA ?
    Or Anywjhere in Australia ?

  2. John

    Hi David, as we are located in the UK i’m not sure, however, Amazon may ship them to Australia as there generally lightweight they may not charge too much for shipping, worth looking into.

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