Updated at: 04-05-2022 - By: Sienna Lewis

Keep little bugs out of your greenhouse, whether you’re a proud owner of a greenhouse for commercial or personal use. Gardeners new to greenhouse gardening are worried about the many insects that make their way in and out of the greenhouses. Other than pollination, some of them are just hungry for the plants they find.

You must remember a few things if you want to keep your delicate plants safe from damaging bugs that could wipe out all of your hard work in the yard.

Tips for Keeping Your Greenhouse Free from Destructive Bugs

The good news is that there are a few things you can do to help keep those pesky garden bugs away from your plants. Follow these suggestions to get started:

Tip #1: Keep your greenhouse clean

Your greenhouse, whether it’s a micro greenhouse, commercial greenhouse, or semi-professional one—no matter how big or small—must be kept clean. There are a number of disease-causing pests, such as spider mites, thrips, aphids, and whiteflies that can be found in and around the enclosed space.

Tip #2: Identify your enemy

You can’t avoid having to deal with damaging bugs, even if doing so can be difficult. This may necessitate the assistance of a specialist, as different pests necessitate various forms of treatment. To put it another way, there isn’t a single solution for insect infestations.

Tip #3: Plant the right kind of grasses and perennials outside the greenhouse perimeter

For the outside of your greenhouse, you can keep thrips out by planting fine fescues and other types of grasses with narrow blades. There are many beneficial insects in your greenhouse, so be sure to surround your plants with some attractive perennials or broadleaves to keep them out of your plants’ way.

Tip #4: Turn the thermostat to 90˚ before you close your empty greenhouse down for the season

The thrips can survive in an empty or freezing greenhouse for a long time. When it’s chilly outside, these bugs can be found perched on weeds and other vegetation as they wait for the weather to improve. Try setting the thermostat up to 90 degrees Fahrenheit for around 50 to 10 days before shutting down your greenhouse for the season.

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Tip #5: Place sacrificial marigolds inside your empty greenhouse

You can use sacrificial marigolds to attract thirsty and hungry thrips after letting your greenhouse boil for 10 days. Before removing the thrips-infested blooms, allow the bugs a few days to travel to the flowers first.

Tip #6: Get rid of stagnant pools of water

If you have a hobby greenhouse, shore flies might start out in modest numbers but quickly grow out of control. For these bugs to thrive, algae is a need. Because algae grows in stagnant water, unless you want to risk eating your plants’ leaves, get rid of any standing water on your greenhouse floors.

Tip #7: Remove your sentimental plants that attract bugs

Aphids, thrips, spider mites, and scales can all be found on some plants. Hibiscus, Mandevilla, and the “Ponderosa” lemon are a few of these plants. Remember that these should not be kept in your greenhouse’s production area.

Tip #8: Introduce bugs that are good for your plants

Introducing beneficial insects such as praying mantis, lady beetles, fly predators, bumblebees, beneficial nematodes, aphid predators, green lacewings, fungus gnats, thrips predators, and more on a regular basis is the greatest way to keep pests at bay. You may accomplish this while also coordinating the planting and harvesting schedules for the various seasons. You should use biorational pesticides instead of those with long residual effects while preparing to introduce beneficial bugs.

Tip #9: Water your plants properly

Your plants won’t thrive if you water them too much and too regularly, as this causes excess moisture levels and shallow roots. Drain flies, beach flies, and fungus gnats might take advantage of your plants if they aren’t properly watered.

Tip #10: Avoid excessive nutrient fertilization

When your plants are flourishing and receiving an abundance of extra nitrogen, thrips and aphid infestations are more likely to worsen.

Should You Get Yourself a Mini Greenhouse?

Yes! While full-sized greenhouses are fantastic, a mini greenhouse is even better for nurturing your seedlings. For people who have limited space in their homes and don’t have a lot of room for a garden, these little greenhouses are ideal.

In order to ensure that your plants get enough sunlight or shade, you may easily move these greenhouses around. Mini greenhouses, on the other hand, are ideal for novice greenhouse gardeners. Mini-greenhouses are great for starting seeds because they’re small and easy to maintain.

Natural Remedies For Keeping Bugs Out Of The Greenhouse

Since natural predators can’t get to your plants in a greenhouse, you’ll have to take on the additional task of controlling pests.

Spraying the plants with a natural insecticide is the best way to protect them. There’s no way for the bug to get through. A wide range of natural medicines are available for purchase. Each has its own unique method of operation and degree of effectiveness. Despite the fact that these products contain organic ingredients, it is critical that you follow the safety instructions offered.

  • As far back as 1920, Bacillus Thuringiensis (BT) has been an effective bacteria-based technique for controlling pest infestations, both inside greenhouses and outside. It is an all-natural substance that produces pesticide proteins in the form of crystals or spores. It does not affect anything beneficial to the environment, and it is not detrimental to humans or any other living creature.
  • Bacteria identified as saccharopolyspora spinosa affects a bug’s neurological system, causing it to become agitated. This insecticide is beneficial to a wide range of species, but further research is needed to determine when the optimal time to eradicate the pests is.
  • Neem oil suffocates insects and repels them at the same time. A bug will flee if it sees even the slightest hint of oil on a plant. Azadirachtin, a naturally occurring pesticide, was isolated from Neem. It has a direct impact on a bug’s capacity to molt and discourages the reproduction of insects. This option is more effective if you get the pure substance rather than the “concentrate,” which is less potent.

Tips On Keeping Bugs From Entering The Greenhouse

It’s possible for a bug to enter the greenhouse and feed or pollinate a plant every time the entrance is opened.

To enter or leave, you can take them with you in any of these modes of transportation. Insecticidal barriers are required to keep the plants safe once they are inside. In an ideal world, the goal would be to prevent as many people from entering as possible. Various barriers, screens, and traps can be used to prevent any holes or openings in the greenhouse.

  • Understand your origin. This will ensure that your plants are free of bacterial or fungal problems because you are starting them from treated seeds purchased from a trustworthy dealer with whom you have been doing business for a long time. You can never be sure that a plant you buy from a nursery or gardening store is healthy or free of pests. It’s safer to grow plants from seeds that have been pretreated in your greenhouse.
  • Plants from the outdoors should never be allowed into the greenhouse because they may carry pests. And if you need to work in the garden, do it after you’ve finished your task in the greenhouse.
  • It’s also important to keep the door shut at all times!
  • When repotting, be careful. When beginning seeds or planting in the greenhouse, use a’soilless mix,’ which should be used when repotting plants outside the greenhouse. Insects and microbial pests that live in the soil can be introduced into greenhouse plants by using any soil mixture. To begin the recycling process, sterilize the pots using a 10 percent bleach solution.
  • Maintain the cleanliness of any equipment you use. All gardening instruments should be disinfected with 10% bleach before to use in the greenhouse in the event that bugs or bacteria have been brought in from the outside. Each time they work on a plant, they should go through the disinfection procedure.
  • Keep your greenhouse clean. Remove any fungi or mold that may appear on a regular basis. Disinfecting the space completely and removing everything is important at the change of seasons. In order to avoid attracting bugs, make sure there is no standing water in the greenhouse.
  • Before allowing new plants into the greenhouse, check to see whether they are clear of any contaminants. When a single insect is overlooked on a new product in the greenhouse, the entire harvest is at risk.
  • Keep the area you’re in clean and orderly. Pests are drawn to delicious smells and prefer hiding out among piles of trash. Make sure that sugary drinks are covered when working in the greenhouse (if you must bring them in at all). Organize pots, tools, and anything else that might be in the kitchen, and keep the interior clean of “clutter.” Keep the grass cut and the bushes manicured on the outside.

The Top Enemies of The Greenhouse Garden

Gardening in a greenhouse is distinct from that of an outside plot since it is humid, warm, and protected from the elements. It’s possible for a wide variety of pests to enter the garden and feast on the plants. Some of these pests are harmless, but others may wreck havoc in a greenhouse.

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Fungus gnats, aphids, and whiteflies are among the insects that must find a way out. It doesn’t matter what time of year it is; these bullies are among the most frequent and persistent infiltrators. Let us examine each one in turn.

    • This bug can be identified by its distinctive oval form and golden color. The aphid has long been regarded as the world’s most destructive pest. They tend to congregate in groups under the leaves of the plant. The female’s ability to reproduce without mating is very remarkable. Only females are born, and she does so at a rapid rate (within a week).
    • If you don’t get rid of aphids as soon as possible, they’ll take over your greenhouse.
    • Inspect the plants frequently, keeping an eye out for any changes in the surrounding environment.
    • If you have to be away for a long time, be sure you have someone who can do these tasks for you. If aphids take possession of the greenhouse, it could be completely destroyed if it is left untreated.
    • Using a spray bottle or a garden hose, you may easily wash away aphids with water if you locate them early enough in the infestation. The aphids won’t want to return if the plant’s leaves are gently washed and flipped over several times. Care must be exercised when working with the delicate vegetation.
    • As long as the aphids aren’t overindulging on too many leaves, the overall health of the plant should not be affected. Until the aphid population is reduced, you’ll need to continue the eradication operation every other day.
    • During the colder months, when some species acquire wings, it is easier to spot these nocturnal creatures. It’s common for them to spread out around the greenhouse, so be sure to keep an eye out for them there.
    • They prefer the top layer of soil, where they will lay their eggs, for this reason. It’s the greenhouse garden’s second-worst problem, behind pests. Gnats that look like fruit flies hatch and are a common nuisance to folks who care for houseplants. As well as seeds and leaves, they also enjoy rotting plant tissue.
      • Cover the ground, as this is where they live. Stones or crushed granite (poultry grit) can be used to prevent the eggs from hatching.
      • Use irrigation systems that don’t wet the soil.
      • Yellow adhesive tape can be used to attract gnats once they have wings.
      • When they congregate in windows or on the sills, you can use a cleaning solvent to get rid of them.
    • The greenhouse is infested with a variety of pests. Right now, there’s a handful in contention for third place. Whiteflies, on the other hand, appear to be the most prevalent year-round pollinator. In the same way that gnats are eradicated using sticky traps, these pests can also be eradicated using sticky traps.
    • These are small, slender insects that lurk in buds and shoot tips, sucking off the plant’s vitality while remaining undetected. It’s common to see the damage before you know the insect is present. Cut off any damaged flowers or buds, then use an insecticidal soap or neem oil to clean up the rest of the plant. Staples may be useful because some thrips can fly.

It’s impossible to maintain a bug-free, sterile greenhouse atmosphere. Ideally, you want to provide your plants with an environment that is as close to their natural habitat as possible, where they can protect themselves and eventually recover from an attack.

Make Friends With These Bugs in The Greenhouse

Having a lot of bugs in the garden is a good thing. These are the animals you want in the greenhouse to assist in the battle against pests. In the greenhouse, your work is multiplied by two if you kill beneficial insects.

It’s critical that you know which insects are beneficial to your garden because they can play a critical role in ensuring its long-term health.

If you want to be a successful gardener or horticulturist, you need to know everything you can about the environment and the bugs that live there, so you can use them to your advantage.

The natural predators of pests in your garden can frequently eliminate them in a natural way. As a result, even natural insecticides may remove the harmful bugs, but they may also remove the beneficial ones. A well-functioning ecosystem relies heavily on knowledge. If you’re looking for a few of these bugs on your team:

  • A Green Lacewing. This insect, the green lacewing, is among the most famous and well-known of the beneficial insects since aphids are its preferred meal. This insect enjoys eating thrips as well. It is able to eat a wide variety of pests since it has a large appetite.
  • Mantis in prayer. This creepy-looking insect eats anything from aphids to flies to moth larvae, so don’t be alarmed by its appearance. It is a big bug that can kill any other pest, and some giant species may even prey on small birds.
  • A ground beetle, or bumblebee. It’s easy to mistake this bug for a bad one, but it eats maggots, cutworms, and flies. Large black larval beetle that aids in soil aeration and composting.
  • Hoverfly. The golden markings on this fly lead many people to believe it is a bee. Syrphids are sometimes known as hoverflies. Unlike a butterfly, these flies are unable to sting or bite, but they can pollinate like one. Mealy bugs, aphids, and other pests are all favorites, but they also enjoy parsley.
  • Ladybugs in either red or yellow. Mites, aphids, thrips, and scale are all prey for this garden defender. Keep them well-fed once you’ve got them. This kind of beetle relies on pollen and minor pests for its survival. For pollen, cilantro and fennel, caraway and dill, as well as marigolds, are the best options.
  • Assassin bug. Caterpillars are nearly unstoppable in the garden, making a bug that eats them all the more impressive. The assassin insect is a good fit for the job description. If you’ve ever seen a grub or leafhopper, you know what I’m talking about.
  • Mites. There are good mites and evil mites in the house.. An effective thrips predator mite has been identified. Spider mites are harmful because they eat on plant tissue. Use a book like this (link to Amazon) or a university extension website like this one to learn more about which is which.
  • Pollinators. The importance of pollinators cannot be overstated, and this guy is the most important. Bees and honeybees need flowers, so you’ll need to be prepared with them at all times. The pollinators who keep us supplied with food and nectar include a wide range of other winged creatures such as moths, butterflies, flies, hummingbirds, and wasps.

Bugs can either save or destroy your greenhouse garden. Believe it or not, you have the power to change your situation. In order to become a greenhouse grower, you’ll need more than just a basic knowledge of plants and vegetation.

In order to learn about the ecosystem as a whole, there is an educational process. You need to treat the plants as though they were grown organically, including making friends with predator bugs that can naturally eliminate the pests that wreak havoc on them.

You don’t need to use goods or insecticides if you know what bugs to look for.

As a gardener, you must learn about the numerous bug species and their roles in the ecosystem. In order to keep the number of pests at bay, you must allow beneficial bugs to enter your environment. You’ve got a hand in constructing a gorgeous, natural life cycle inside the confines of your greenhouse.

The good bugs will do the work for you if you take care to keep them around and keep the quantity of “bad” bugs under control.

How To Avoid Bugs In A Mini Greenhouse Successfully


Preventing bugs from entering the micro greenhouse is the simplest and most effective approach to do it. It’s at this point that you have the most power and are most likely to succeed. However, if you want to succeed in the small greenhouse, you’ll need to maintain two traits during your stay there: diligence and activity.

It’s common for pests to enter your greenhouse through the new plants that you bring in. Even if the plant doesn’t appear to be infested, it might be beneficial to cure it before transferring it indoors. Also, you never know where insects or eggs may be hiding in your new plants, so be sure to check them completely before planting.

Waiting at least two weeks before bringing in your new plants is a great approach to ensure that they are clear of bugs. It’s a good idea to invest in a separate location for the new plants. Contact your producer to find out what pesticides they’ve used so that you can use a different one.

Sticky traps, used in conjunction with standard scouting, can expedite the inspection process. This manner, you’ll be able to easily identify the bugs. Sticky trap cards can be used horizontally and vertically to catch a wide variety of pests.

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Inspection and separation, in addition to screens on all openings and inspecting beneath walls, will help prevent unwanted bugs. It is possible for pests to get in through the vents, behind the fans, even on the greenhouse floor itself. Keep other plants out of the area around the micro greenhouse since they can serve as a breeding ground for pests.

Sanitation and maintenance

Poor sanitation and care in the micro greenhouse is a major contributor to the growth of pests and bugs. The introduction of pests including aphids, mites, and whiteflies can occur if weeds are not removed. It is possible for thrips to thrive in even the tiniest of pieces of debris that you leave in the greenhouse.

Shore flies and spider mites can thrive in stagnant containers of water, while certain ancient plants may also be infested with these pests. Additionally, practices like as over-fertilization and watering incorrectly aggravate pest infestations. Finally, pests’ ability to survive can be influenced by the greenhouse’s temperature.

Insect education

In the small greenhouse, not all bugs are your adversary. For example, researchers at the University of Massachusetts Amherst have noted that greenhouse pests’ natural enemies, including insects, can be used to control them. If you’re producing veggies in a little greenhouse, biological control would be a better option than pesticides, which have a variety of safety measures.

A variety of helpful insects, including Encarsia Formosa and Eretmocerus eremicus wasps, predatory mites, pirate bugs and ladybird beetles, feast on whiteflies and other pests in the garden. Natural enemies of common greenhouse pests are well-documented thanks to university extensions, so finding the right insects to combat bugs and pests is a cinch. The best part is that you don’t have to be concerned about pesticide-like side effects when using them in the greenhouse.


You’ll decide the best line of action based on the extent of the infestation. Low-level infestations can be addressed using biological control and spot treatments. On the other hand, if your little greenhouse is infested with pests, a pesticide treatment may be necessary.

Because you don’t want pests to spread in the little greenhouse, you want to take action quickly. A modest number of them can soon escalate into a more serious issue. Pesticide use can be harmful to the environment and other living organisms; therefore, if you must use one, choose one that is biorational.

The term “biorational pesticide” refers to a type of pesticide that is less toxic since it is derived from plants. Mini greenhouses can be treated with less danger due to the fact that they have a low toxicity level. You’ll find that their active and inert substances are safe and do not need government licensing.

Thoughts on How to Keep Small Bugs Out of Your Greenhouse

Every gardener should be aware of the need of learning how to keep little insects out of their greenhouse. Plant health and pest control can be improved by following the advice given above.