Best Heated Propagators: Get a Jump Start on Your Seeds

Updated/Fact-Chacked on May 18, 2023 by Gareth James

Gardeners have some challenges to overcome when it comes to growing plants early: unexpected frost, cold temperatures, and insufficient light can all kill your young seedlings – what’s more, these conditions can drag on into the spring.

A heated seed propagator is a solution to the uncertainty that surrounds sowing seeds. Think of it as an incubator that helps you kickstart your seeds into early germination. With this mini greenhouse, you can provide a conducive environment for the young seeds. It allows you to control the temperature and other vital factors that support seed germination.

Heated propagators will make your seeds germinate much faster; we are talking days instead of weeks.  I currently have a heated propagator running 24/7 and simple plastic tray propagators; split testing the two with the same seeds has been interesting.

There are many types of heated seed propagators in the market. If you’ve never bought one, you are bound to be unsure of what would work for you. Also, it could be that you are looking to upgrade from your current unit.

In this post, we cover the best-heated seed propagators available in the market today. All have been tested by myself for or one of the other writers at Platsman Media.

1 Garland GAL36FB Fab 4 Electric Heated Propagator

Our top pick for the best-heated propagator is the Garland FAB 4 electric heated propagator. This propagator has four compartments allowing you to germinate different seeds in each of its four compartments. This unit boasts an efficient 10-watt carbon fibre element, which guarantees you even heat distribution. You can adjust its vent lids to your liking. The heating element is situated at the bottom.

The entire system is about 38.5 cm long, 15cm long, and  24 cm wide. It is large enough to accommodate a significant number of seedlings.  Despite its size, its running cost is quite low. You don’t have to worry that your energy bills will skyrocket.

With this unit, you can expect a soil temperature rise of up to 8°C. It maintains warmth at all times because it doesn’t have a thermostat. Additionally, it is light and easy to move around. The Garland 4 propagator is best for entry-level gardeners.

After reading the reviews, many people said the propagator did not get hot – I think they were missing the point! You can feel the unit’s warmth by simply touching the white base.  This propagator warms the soil so well, you really have to be careful not to allow the soil to dry out. Initially, I placed the unit on a window sill above a radiator, which was too warm. Seedlings sprouted within days but died as they were too warm and the soil dried out in hours. After moving the propagator to a cooler location, I’ve had much more success.

This unit is perfect if you are growing seeds with children; standard trays can take weeks for seeds to germinate and kids can lose interest.

2 EarlyGrow Domed Propagator

If you are looking for a bigger, strong, and taller propagator, the EarlyGrow Domed propagator could impress you. It has a massive, heavy-duty tray. This is not your ordinary plate. It is made with durable PP materials which can withstand heavy plant containers.

The Early Grow Domed propagator has two large vents. It also comes with a crystal-clear shatterproof lid. Should the need arise, you can use its clips to secure the lid. Besides that, you can open or close it to regulate humidity and provide favourable conditions for germination.

The domed propagator has a capacity of about 60 ‘2×2’ seed germination plates. Apart from that, it has a height extension that provides ample depth for plants to thrive under the dome. If you don’t need the extension, you can always remove it.

Even though the dome is clear, it doesn’t interfere with the grow lights. And it is not damaged by UV light.  If you are an organic gardener, this unit is perfect for you. Its sturdy build allows you to move it around as you wish. The only downside is that you have to buy a heated mat separately.

3 Suttons Super 7 Electric Propagator

The Suttons Super 7 propagator is a good match for gardeners who like to grow vegetables and fruit seeds. In terms of flexibility, this unit has a lot to offer. For example, it has seven tabs, and each one of them has a vented clear lid.

This propagator suits new gardeners. It generates gentle and stable heat for your seedlings. With this propagator, you get a 13-watt heater.  The heat is enough to get your planting medium warm enough.

The Unit measures 76 cm x18.5 cm x14cm. Its size allows it to sit on a standard windowsill comfortably. Given its size, the performance of the Suttons Super 7 electric propagator is commendable. You can use each one of its compartments for a different seed variety.

4 Stewart P035B Essentials Electric Propagator

The Stewart P035B Essentials electric propagator is simple and user-friendly. It does exactly what you want it to do. With its on-and-off button, you start and stop without any qualms.

Its small size makes it easy to handle. You can move it from one location to the other without a problem. Also, it will not occupy a lot of your indoor space. So, if you are operating in a limited space, this is your device.

This unit is non-thermostatic. It comes with a clear and easy-to-adjust lid. With this kind of cover, you can adjust the temperature and humidity. Furthermore, the lid supports ample light transmission. And this invigorates photosynthesis and fast growth.

The device runs on a 22W energy-efficient heater. What’s more, it is regulated to prevent heat loss from the heater. Its high-quality plug and quality cable enhance convenience.

Depending on your pot size and other needs, this propagator allows you to switch its seed trays as you wish. The unit has a sturdy base, it is compacted and can last for years.

5 Selections Jumbo Windowsill Heated Plant Propagator 

If you are looking for a windowsill unit, try the Jumbo Windowsill Propagator. You can fill it with soil and plant the seeds or add containers. . Unlike the others, this device has thermostatic control that maintains the soil or the containers at 70 degrees Fahrenheit.  It comes with a clear lid that promotes sufficient light penetration. The lid lifts with ease and it also has adjustable vents for humidity control.

The Jumbo Windowsill heat propagator is 20 cm long, 20 centimetres deep, and 80 cm wide. With a 12W heating apparatus, It maintains heat at 21°C throughout. The only problem you will likely have with this propagator is its flimsy lead. However, if you use it carefully, you will love it.

6 Thompson and Morgan Heated Propagator with Air Valve Vent

The heated propagator with air valve vent by Thompson and Morgan stands out in its own ways. It is well-built with a durable PVC plastic material, has a built-in roof vent, and comes with a 1.5m power cord. The unit is designed to provide the ideal microclimate for germination.

You can sow several seeds in each one of its cells. Nonetheless, 1 or 2 seeds is the ideal number. If you use quality compost, this unit will hardly disappoint you.  Seeds tend to germinate quickly in this propagator. As soon as they are too big for it, you should re-pot them.

The unit measures L39 x W25.5 x H19. If you have space constraints, this propagator will not be a problem. It is great for general use. In terms of energy consumption, it will not consume much. You may not even see a difference in your energy bills.

7 Sankey 38 cm Growarm 100 Propagator Kit

At first glance, the Sankey 38cm Growwarm looks simple. However, it has everything a gardener would want in a heated propagator. It comes with an 8-watt heating system. But its capillary water mat makes it stand out.

The Sankey heated propagator has 2 trays to plant different vegetable and fruit seeds. You can adjust its ventilation controls to meet your needs. And the unit has a clear top cover. When it comes to temperature regulations, its controls are electronic.

With this unit, the base gets warm evenly. This is one of the reasons why it is incredibly efficient. You can use it to germinate a range of seeds including chillies and tomatoes. Whether you are a novice or a pro gardener, you are likely to appreciate working with this unit.

>> How long does it take for a seed to germinate?
>> How to start seeds in a paper towel
>> How to speed up seed germination
>> How to care for seeds once sprouted
>> Seed compost v multi-purpose compost
>> Should you soak seeds before sowing?

Electric Propagator Buying Guide

If you are on a quest to find a reliable heated propagator, here are some features to look for;

Size

When considering the size of a particular unit, remember that a big propagator takes time to heat up. But on the brighter side, your seeds are not likely to rot due to the effects of condensation. Ask yourself what matters. Is it the capacity of the unit or the heating speed? You also need to think about the space available for the propagator.

Thermostat

Some heated propagators are self-regulating, but others require manual adjustment. You need to decide which one suits your situation best. Choose between a unit with an automatic or manual thermostat. Other heated propagators have neither. If you can monitor your unit closely, you can purchase a propagator without a thermostat.

Ventilation

When it comes to heated seed propagators, ventilation is of the essence. Always go for a heated propagator with a ventilation system. If the temperatures in the unit rise to high levels, the thermostat will be overwhelmed.

Budget

Your budget will also determine the kind of heated propagator you can afford. If you are just starting out, decide how much you want to spend. And after you learn the ropes, you can graduate to a high-end heated seed propagator.

A heated propagator will undoubtedly improve your chance of success when germinating seedlings. It will help you have more control of the process. However, you may waste your time and resources if you don’t have the right device.

If you’ve read this review, you are a step closer to finding an appropriate heat propagator for your project. You can be confident that whichever you pick will do a great job.

Heated Propagator FAQS

Do heated propagators use a lot of electricity?

The amount of electricity a heated propagator uses depends on its wattage and how often it’s on. However, most heated propagators are designed to be energy-efficient and use relatively little electricity – often no more than a standard light bulb. The average seed propagator will use 8 watts daily, so around 5p/day.

Is it worth getting a heated propagator?

The value of a heated propagator depends on your gardening goals. If you’re interested in starting seeds early in the year, growing plants with high heat requirements, or simply wanting to speed up the germination process, a heated propagator can be a worthwhile investment. It also helps maintain consistent temperature and humidity, enhancing overall seedling health and success.

Do you leave a heated propagator on all the time?

It’s not necessary to leave a heated propagator on all the time. The goal is to maintain a consistent and appropriate temperature for the seeds you’re germinating. At night, when ambient temperatures drop, you may need to keep it on. But during the day, especially if it’s warm, you might not need it. A thermostat can be useful to manage this. Saying this, I leave mine on 24/7.

How often should you water seeds in a heated propagator?

Watering frequency in a heated propagator depends on the type of seeds and the environmental conditions. It’s important to keep the soil or compost evenly moist but not waterlogged. Check daily, but water sparingly. The enclosed environment of the propagator helps retain moisture.  Don’t place it on a window sill above a radiator, as the solid will dry out very quickly (my problem with my south-facing window).

Should I leave vents open on the propagator?

Leaving the vents open on a propagator can help control humidity and prevent fungal diseases. If there is too much condensation, opening the vents can help. However, you want to balance this with maintaining a warm environment, so adjusting the vents as needed is key.

How long do seeds take to germinate in a heated propagator?

The germination time for seeds in a heated propagator can vary greatly depending on the plant species. Some may germinate within a few days, while others can take a couple of weeks or more. On average, seeds germinate faster in a heated propagator compared to regular conditions.

What temperature should a propagator be set at?

The temperature setting for a heated propagator depends on the seeds you are trying to germinate. Generally, most seeds will germinate at temperatures between 15°C and 25°C. However, always check the seed packet for specific temperature requirements.

Is condensation in a propagator good?

Condensation in a propagator is a sign that it’s maintaining a humid environment, which is beneficial for seed germination. However, too much condensation could lead to overly wet conditions and the potential for fungal growth. If there’s excessive condensation, it may be a good idea to vent the propagator to reduce the humidity slightly.

Mary

Mary shares a passion for gardening with her husband John, though she is more focused on growing veg on their allotment at St. Margaret’s Allotments, Durham. Mary also works in the lawn care industry and manages the lawns for the Durham University campus.