greenhouse fumigator

3 Best Greenhouse Fumigators

2022 Review for the UK Market

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In this guide we’ll look at the best greenhouse fumigators for the UK market.
We’ve compared ease-of-use, design, effectiveness and cost
to give you our top recommendations.

What Are The UK's Best Greenhouse Fumigators?

IMAGE RECOMMENDED PRODUCTSPRODUCT FEATURES
  • Easy to use
  • Eliminates pests and fungal spores
  • Good value for money
  • Easy to use
  • No need to remove plants
  • No nasty smell
  • Garlic oil formulation
  • Non-toxic
  • No need to remove plants

Read Our Greenhouse Fumigator Reviews

Battles Greenhouse Sulphur Candle

FEATURES RATING PRICE
FEATURES
  • Easy to use
  • Eliminates pests and fungal spores
  • Good value for money
OUR RATING
98
PRICE
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Battles Greenhouse Sulphur Candle Review

An easy and effective way to disinfect the greenhouse, this Battles Greenhouse Sulphur Candle is easy to use and quick to work.

The 225 g candle is sufficient for a 3 x 2 m (10 x 6 ft) greenhouse – any larger will require further candles to be used.

It’s incredibly easy to set up – simply put it on a heatproof surface inside the greenhouse and remove the lid. There’s a ‘wick’ inside to light, although it’s more like a rolled-up piece of paper, and this can be the trickiest part of using this candle. Persuading the paper to light can be a little tricky.

Nevertheless, once it’s going, it produces plenty of sulphuric smoke and seems to effectively reach into all corners of the greenhouse. Sulphur is renowned for eliminating pests and fungal spores that can infect and infest your plants.

Seeing as this is a very potent product, the most important thing is to follow the instructions carefully: do not remain in the greenhouse while the candle is burning. Do no re-enter the greenhouse for at least 12 hours. After about 12 hours open the greenhouse and allow it to fully ventilate before entering.

Overall, this is one of the best greenhouse fumigators to use for annually disinfecting the greenhouse. Be aware that if there are gaps in your greenhouse the smoke may escape, so these should be sealed before fumigating. Also, all plants need to be removed for the fumigation process.

Pros

  • Economical and convenient way to eliminate pests and fungal spores from the greenhouse
  • Produces a lot of smoke once lit
  • One candle is enough to fumigate a greenhouse up to 3 x 2 m (10 x 6 ft)
  • Sulphur is renowned for being a very effective fumigator

Cons

  • Wick can prove difficult to light
  • Greenhouse needs to be well sealed or smoke will escape
  • Plants need to be removed during fumigating so difficult to use during winter
  • Sulphur can be damaging to health so instructions must be followed very carefully

Deadfast Greenhouse Smoke Generator

FEATURES RATING PRICE
FEATURES
  • Easy to use
  • No need to remove plants
  • No nasty smell
OUR RATING
96
PRICE
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Deadfast Greenhouse Smoke Generator Review

If you’re struggling with various types of bugs, this Deadfast Greenhouse Smoke Generator can eliminate both flying and crawling insects.

It’s best suited to small/standard size greenhouses, as the actual ‘candle’ itself is relatively small. After placing the fumigator on a heat-proof surface, you’ll need to light the wick and leave it to burn for at least two hours.

Unfortunately, lighting the wick can be a little hit or miss which is the biggest downfall of this product. Sometimes it will go out after very little time, which means it won’t produce enough smoke.

According to the instructions, if there is a very heavy insect infestation, you may have to fumigate up to three times (at five-to-seven-day intervals).

Customers have reported that it successfully gets rid of red spider mite, along with small amounts of other insects; however, it may have a limited effect on larger infestations of insects and more stubborn varieties like white fly.

Be aware that the active ingredient, permethrin, is very toxic to aquatic life so you should be careful about where you use this product and how you dispose of it.

Like sulphur, it can also be harmful to humans, so follow the instructions carefully.

Pros

  • Suitable for small/standard greenhouses
  • Doesn’t produce a nasty smell unlike others on the market
  • Capable of getting rid of red spider mite

Cons

  • May not be as effective as sulphur fumigators
  • Wick sometimes burns down too quickly, meaning not enough smoke will be produced
  • Fumigator inside tin is a lot smaller than you would expect

Pest-Stop Biofume Greenhouse Fumigator

FEATURES RATING PRICE
FEATURES
  • Garlic oil formulation
  • Non-toxic
  • No need to remove plants
OUR RATING
92
PRICE
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Pest-Stop Biofume Greenhouse Fumigator Review

Getting rid of insects without using harsh chemicals is a hard job, but this Pest-Stop Biofume Greenhouse Fumigator contains all-natural ingredients. It can clear small amounts of pests, and won’t harm plants.

This is one of the best greenhouse fumigators if you’re after something non-toxic, but be aware that it is not as effective as a sulphur/chemical fumigator.

One of the primary ingredients in this fumigator is garlic oil. Once lit, it emits a thick smoke that smells extremely garlicky – you have been warned!

The good news is that you don’t have to remove plants from the shed before using this Pest-Stop Biofume, because there are no damaging chemicals. One canister will produce sufficient smoke for a standard greenhouse, and it will burn for approximately two hours.

Unfortunately, as is often the case with natural products, this doesn’t have the same strength or potency as fumigators like the Battles Greenhouse Sulphur Candle. Therefore, if you’re suffering with a large insect infestation, like stubborn white fly, this Biofume Fumigator is unlikely to be strong enough.

However, it’s still a good first-point-of-call for tackling a small number of insects – particularly because there are no toxic ingredients. Just bear in mind that if it doesn’t work, you may have to consider something more powerful (with harsher chemicals).

Pros

  • Does a good job deterring a range of bugs from your greenhouse
  • Natural so non toxic to people, plants and the environment

Cons

  • Produces a very strong and unpleasant garlic smell
  • May not have an effect on whitefly
  • Contains no active pesticide so not as effective as others on the market

How to Choose the Best Greenhouse Fumigator

Greenhouse fumigators can be used to ‘disinfect’ greenhouses.

This process can be done annually, before filling the space with plants, or when a particular problem is noticed – such as an insect infestation.

Some fumigators will act as both a fungicide and pesticide, whilst others are only aimed at getting rid of bugs.

Choosing the best greenhouse fumigator will depend on the problems you’re facing, as well as your personal view on using chemicals. The following information will help you make an informed decision.

Different Types of Fumigators

Fumigators for greenhouses come in the form of ‘candles’. They’ll have a wick to light, and should be sealed within the greenhouse to allow the smoke to properly fumigate the area.

The active ingredient can vary, which is what distinguishes between different fumigators.

Here’s a list of some of the commonly-found active ingredients in fumigators, with their advantages/disadvantages:

Sulphur Fumigators

Fumigators that contain sulphur are by far the most effective. Sulphur is a powerful and effective fungicide/pesticide and it will thoroughly disinfect the greenhouse. Whilst this all sounds great, there are some downsides.

As you may have guessed, sulphur fumigators are very harsh, and these types of chemicals shouldn’t be used lightly. All plants will need to be removed from the greenhouse, and no-one should breathe in the smoke.

It’s extremely important to follow the instructions carefully (as with all products!) to make sure no health problems ensue from using sulphur-based fumigators.

Additionally, when sulphur burns, it turns into sulphur dioxide. This gas can react with water to form acid and can have a damaging effect on plants.

Sulphur also smells very strongly, so be aware of this when using it in your garden.

Permethrin Fumigators

Permethrin is an insecticide. It will not tackle any fungal spores inside the greenhouse. However, it is effective at killing a broad range of insects, which is what makes it useful as a fumigator.

Permethrin is considered less toxic than sulphur, although it can still cause health problems so the product instructions must be followed closely. It’s considered extremely toxic to aquatic life.

Whilst generally not as effective as products that contain sulphur, fumigators with permethrin as the active ingredient can work well.

Garlic (Natural) Fumigators

Not all fumigators contain harsh chemicals, and some rely on garlic oil as the active ingredient to flush insects out. Some insects will be killed by the fumigation, and others will be dissuaded from returning by the properties of the garlic.

Whilst not the strongest of fumigators, it can be good to use natural products at least as a first line of defence. If they don’t work, you may have to move onto something stronger (and harsher), but it’s worth trying first.

Natural products generally don’t harm plants, and can be used whilst plants are in the greenhouse (but, as always – check the instructions of the specific product!).

Preparing to Fumigate

Once you’ve decided to fumigate your greenhouse, there are a few steps to follow to make sure the process is as efficient and safe as possible.

  1. Seal your greenhouse well. If smoke can escape, it won’t fumigate properly. The smoke might also might hang around in the garden, particularly if it’s a still day, and disturb you or your neighbours (you certainly don’t want the smell of sulphur or garlic getting on anyone’s clean washing!).
  2. Remove plants from the greenhouse (this step may be optional if you are using a fumigator with natural ingredients – check the instructions!). Most people fumigate their greenhouse during the winter months so that they can safely put plants outside without killing them. If you need to fumigate when it’s cold out, you’ll need to prepare somewhere warm for your plants. Fumigating can take 12 hours +.
  3. Make sure no-one needs to enter the greenhouse for any reason during the whole fumigation process. Until the greenhouse has been properly ventilated, after fumigating, don’t allow anyone inside.

How Many Fumigators to Use

Generally speaking, one fumigator will be sufficient for a standard 2.4 x 1.8 m (8 x 6 ft) greenhouse. However, the instructions for individual products may state otherwise, so be sure to check them first – some products may work over larger or smaller spaces. It’s also a good idea to check customer reviews, to see how the products performed in real life. This can give a good indication of how many fumigators to buy for your particular greenhouse.

Although it may not seem immediately obvious, you can use more than one fumigator. Therefore, if you have a larger space to fumigate, you may want to consider using two or even three fumigators. Select the number of fumigators you require based on the size of your space and the product instructions – using an excessive amount will just waste money and could even be dangerous.

Greenhouse Fumigator FAQs

How do you use a greenhouse fumigator?

You should always carefully follow the specific instructions on your fumigator for safe use. Here are some general outlines:

  • Depending on the type of fumigator you may need to remove all plants from the greenhouse. This will be the case if you are using a sulphur candle; however, for some products it will not be necessary.
  • Close the windows and doors of your greenhouse.
  • Place the fumigator candle on a fireproof surface, such as a brick, in the middle of the greenhouse. If you are using more than one, space them out evenly.
  • Light the candle then leave the greenhouse, closing the door behind you. Wait outside to check that the candle is lit, and smoke is being produced. Sometimes it can be fiddly to get the wicks of these to light so you might have to go back in and relight it.
  • Once the candle is smoking you can leave it to do the job. Follow the instructions on the fumigator to know when to open the doors and ventilate the space. You should not enter until it is completely ventilated which may take a full day.

Are sulphur fumigators bad for the environment?

Sulphur fumigators can have a negative impact on the environment. Burning sulphur releases a gas called sulphur dioxide. When this mixes with moisture, it can form acid. Therefore, if it mixes with water droplets on plant leaves, for example, it can burn them.

Additionally, breathing in sulphur dioxide can be very dangerous. When using a sulphur fumigator, utmost care must be taken not to breathe in any of the fumes. This applies to all animals.

How often should I fumigate my greenhouse?

Many gardeners choose to annually fumigate in order to keep on top of any problems. This is often done around Autumn, when plants can still be outside, but winter is just around the corner. You can also fumigate if there is a particular problem – such as an insect infestation – that you feel needs to be dealt with.

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