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Greenhouse-Grown Does Not Mean Organic. Here’s Why

Growing your own healthy food in a greenhouse is a fun way to provide fresh food for your family. Growing organically means that everything used in producing your food is exempt from toxic chemicals. Organic gardeners only use natural-based products to keep their produce free from pests and disease.

Greenhouse-grown does not necessarily mean organic. Certified organic produce is grown in strict adherence to rules laid down by the NPO. If the greenhouse growing operation is set up in accordance with these rules, then the product can be certified 100% organic.

Produce grown in a greenhouse provides fresh food all year round. Many commercial greenhouse growers use chemical pesticides and heavy-duty fungicides to control pests and disease, but smaller growers are likely to use natural organic products to keep pests under control by growing food in pots and containers. Let’s discuss greenhouse growing.

What Does Organic Vegetable Growing Mean?

Growing organically means growing plants without using any chemical fertilizers or pesticides, the way our grandparents did in the old days. The only fertilizers added to the soil are from homegrown compost bins or commercial products that carry organic certification. Organic matter is used to improve the condition of the soil, producing healthier food.

Some commercially prepared and prepackaged fertilizers, soils, and pesticides can carry organic certification.

However, for the home greenhouse grower, building your own rich organic compost is the best way to not only repurpose unwanted food scraps but has the advantage of allowing you to know that your compost is entirely organic and chemical-free.

Organic greenhouse growers rely on hand-weeding, crop rotation, companion planting, organic compost and fertilizers, as well as natural remedies to produce healthy, chemical-free food. A greenhouse growing system is the best way to grow seasonal and non-seasonal crops year-round in a controlled environment.

The Definition Of Organic Is Not Always What It Seems

Most people understand organic to mean healthy, non-toxic produce. If the produce that we buy at the store has an organic label on the packaging, then that is good enough for us, and we will purchase it.

But, does a label really mean that the produce has been grown according to strict organic methods starting with the soil and growing mediums, or does it only mean that no toxic pesticides were used to control disease and pests on the growing plants?

By buying organic produce, you should feel confident that you are indeed getting a completely 100% organically grown item.

  • People with food allergies will often buy organically grown produce, hoping to avoid chemicals and preservatives affecting their specific allergy.
  • People who have food allergies generally find that their symptoms lessen or disappear entirely after eating produce without any chemicals or preservatives.

More and more health-conscious people are buying organically grown produce to avoid chemicals and preservatives found in commercially grown produce and obtain the nutritional benefits and antioxidants found in organic produce.

Here’s a great video to help explain what organic is:

Does Greenhouse-Grown Mean Organic?

Although many greenhouse growers follow organic growing principles, not all greenhouse operations are organic. Some more prominent commercial farmers use greenhouses to start seed growing in trays and containers with the idea of transplanting the seedlings into fields.

Greenhouse-grown does not automatically imply that the plants are grown organically. Organic growing practices need to be followed in the greenhouse growing operation for the plants that come out of it to be considered to be organically grown or organic-certified.

Sometimes chemically enhanced soils and toxic pesticides are used to control pests in the greenhouse environment, so the growing plant is already full of non-organic chemicals before it is planted into the field.

It is easier to follow organic principles when growing in a greenhouse as the environment is more controlled from a pest and disease perspective. Hobby greenhouse owners or home greenhouse growers can use home-grown compost and natural pesticides more easily than larger commercial concerns.

Any greenhouse-grown produce should display the organic label of authenticity if it is indeed grown organically.

What Is The Difference Between Organic And Greenhouse-Grown Produce?

Organic soil is the only accepted growing medium in an organic operation. If the original soil used in the field or the greenhouse is not entirely organic, the new soil can absorb the chemicals already in the soil and become contaminated.

Any produce can be grown organically when the correct practices are used, whether grown in a field or a greenhouse. Not all produce grown in a greenhouse can be certified as organic.

While growing produce outdoors allows the plants to soak up the sun, the indoors controlled environment of a greenhouse allows the plants a better growing environment.

Here’s a great video that shows the basics of greenhouse growing to give a better idea:

Can You Get Your Greenhouse Organically Certified?

A greenhouse farming operation can be certified as organic if you meet the strict organic standards set by the NOP. While there is not too much difference between running an organic greenhouse and a conventional greenhouse, there are some things to consider before setting up your organic greenhouse operation.

Grassroots principles mean that you understand what comprises organic growing and the requirements of running a 100% organic greenhouse operation.

If you can follow these principles in your greenhouse without compromise, then you can run a successful organic greenhouse growing operation.

Unless your greenhouse follows strict organic growing principles, your produce cannot be certified as 100% organically grown.

The structure of a greenhouse is an essential consideration before starting your organic growing operation. Light, heat, ventilation, and air circulation are critical to creating the right environment in a greenhouse. Without the right conditions, plants with not thrive.

Choosing The Right Soil For Organic Greenhouse Growing

The key to organic growing is the soil. Healthy soil will feed and produce healthy plants. Adding organic matter like home-grown compost to the soil will improve the texture and moisture retention and nutrients to the soil and improve drainage.

For the best growing results and healthy vegetables, always start with organic soil and a mixture of compost and manure. The Organic Soil Here (link to Amazon) is a good place to start.

  • Different plants have different needs, so only add compost or manure after deciding what you will grow in each bed or container.
  • Organic soil is crucial to any organic growing operation as it is much weaker than inorganic soils, is free from chemicals, and provides your plants with the nourishment they need to survive.

If you are planning to plant any seeds or seedlings directly into an existing bed, it would be good to test the soil first to determine if it contains any toxins and so that you can fix any problems.

In addition, a soil test will determine the PH balance and if any extra nutrients or fertilizers are required.

The best organic soil for growing in a greenhouse should consist of 60% loam soil, 30% compost, and a 10% potting mix of peat moss, perlite, and vermiculite. Perlite is naturally acidic, so don’t use more than 20% in the soil mix.

Here’s an excellent video showing how to make organic soil for a garden:

Choosing The Right Growing Containers For Organic Greenhouse Growing

Choosing the proper containers for growing plants in greenhouses is essential. Plant and seed containers come in various sizes and are used for different jobs. Sometimes small-volume plugs are used for growing seedlings, while seeds are germinated in trays.

  • Bio-degradable pots are ideal for starting seedlings as they can then be planted directly into the soil in a larger pot or outdoors in the field.
  • Many of these pots are made from natural fibers like cow manure, coir, or compressed paper.

Always visit your local garden center to see what is available before starting your growing.

The Right Seeds For Organic Greenhouse Growing

When growing organically, the best way to start is with the correct soil and organic seeds. Search online to find a list of seed companies near you that sell organic-certified seeds.

The organic-certified logo should be displayed on every packet of organically-grown seeds to guarantee that they have been produced according to organic standards.

Some seeds are grown using organic methods but are not necessarily certified organic, so always check the packet to confirm that the seeds you are buying are indeed organic-certified.

I recommend starting your search for Organic Seeds Here (link to Amazon) they have a wide variety and usually ship quickly.

Your local garden center should be able to supply you with certified organic seeds if you cannot find them online. Most reputable organic growers are happy to share their knowledge on growing the organic way.

  • Growing seeds in a greenhouse will give them an excellent start to the growing season.
  • The right time to plant seeds is six to eight weeks before the first frost of the season.
  • Keep an eye on the weather updates and plan for the season in your geographical area.

The growing medium is essential when starting seeds in a greenhouse. When growing seeds, always use the medium which is specific for starting seeds, such as peat or a seed growing potting soil. Be wary of using regular potting soil as it is generally too strong for seeds.

  • Plug trays or even small plastic cups with holes poked through the bottom are ideal containers for starting seeds.
  • Fill up each hole with the growing medium that you are using and plant the seeds into the soil according to the instructions on the packet.

Avoid planting multiple seeds in a cup or tray as the roots from the growing plants can get tangled, making it difficult to separate them out when they need to be transplanted.

The Right Pest And Disease Control Measures For Organic Greenhouse Growing

Pests can attack organic plants grown in a greenhouse. These pests need to be managed to prevent damage and disease on your produce.

Although some pesticides are toxin-free and can be used for organic growing, the best way to control pests and disease is through an integrated pest management system (IPM)

  • IPM is a management system that does not use pesticides but instead relies on manually removing pests from plants.
  • Pests like snails and slugs are simply removed from plants and placed somewhere else or destroyed.

Prevention methods like chemical-free barriers and copper barrier tape are placed around plants to repel snails and slugs. Fabric covers can be used to drape over the plants to protect them from pests. Home-made repellent sprays are an excellent way to destroy invasive pests.

Beneficial insects like ladybugs (good bugs) should be introduced to an organic garden to limit damage from pests. These good bugs will often eat nasty bugs that damage your plants. An organic grower should always research which are the best bugs to have in an organic garden.

The Advantages Of Growing Vegetables Organically In A Greenhouse

With the number of toxins used to control pests and diseases on commercially grown produce, more and more people are turning to homegrown produce as a way of ensuring that the food that their families are eating is healthy and toxin-free.

According to recent studies by the Research Institute Of Organic Agriculture, more people are turning towards an organic lifestyle and the benefits that organic growing can provide.

Let’s have a look at some of the advantages of growing produce organically in a greenhouse.

1. Greenhouse Growing Is Environmentally Friendly

Growing organically in a greenhouse is eco-friendly and a sustainable way of producing food. Greenhouse growing reduces energy, and any waste is recycled into the compost used on the plants. Many greenhouse growers collect rainwater to water their plants and use solar lights to provide lighting inside the greenhouse.

2. Organic Growing Supports Healthy Soil

Organic matter in soil is essential for growing healthy plants. Organic matter only comprises about 5% of the soil but is vital as it provides food for other microorganisms like worms and insects living in the soil. Earthworms are a great indication of a healthy soil system. They add nutrients to the soil and improve soil structure.

3. Organic Produce Has More Nutrition And Flavor

Studies have found that organic produce contains about twenty to forty percent more antioxidants than conventionally grown produce. They are also higher in nutrients and minerals while being significantly lower in nitrates and pesticide residues.

No added Genetically Modified Organisms (GMOs) or preservatives are found in organically grown produce.

4. Pollinators Are Encouraged In Organic Growing Greenhouses

Plants need to be pollinated to reproduce. While some plants like tomatoes and peppers are self-pollinating, some plants are immobile and need assistance. Pollinators are insects like bees that carry pollen from one plant to another to enable them to reproduce.

Bees are the best pollinators for a greenhouse as they work diligently to pollinate plants every day. If you are going to encourage bees to pollinate your plants, invest in a beehive on your property to encourage the bees to stay and work in your growing area.

5. Pests And Diseases Are Easier To Control

By controlling the amount of compost in your soil, you can effectively control the pests and diseases which may make their way into your greenhouse environment. Using homemade, natural pesticides and by planting companion plants to attract beneficial insects, you can keep your greenhouse pest-free.


Many people are starting to grow their food in greenhouses to ensure that the quality of the food they eat is up to standard, and more importantly, chemical-free. Growing produce in a greenhouse does not automatically guarantee that it is 100% organic unless the correct processes and principles are followed.

Organic principles must be followed to produce organic food. If any chemicals are used anywhere in the growing process, then the food grown in your greenhouse is not 100% organic and cannot be certified.

Organic produce is generally healthier than non-organic produce. When planning your greenhouse growing operation, make sure that you investigate organic growing principles to provide your family with the best produce available!

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