A variety of herbs in a white bowl with texts in the middle saying Greenhouse Gardening How to Grow Herbs in a Greenhouse

How To Grow Herbs in a Greenhouse

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The smell, taste, and medicinal purposes of herbs make them so unbelievably important to many cultures in this world. If you love them as much as we do, you may wonder if you can grow herbs in your greenhouse.

You absolutely can! Growing herbs in a greenhouse is easy and they are great companions to a lot of other plants. We value herbs for their fragrance, taste, and therapeutic benefits. Most of them are for cooking, manufacturing medicines, and even for pest control, not to mention their spiritual functions.

Start your own greenhouse herb garden with the tips and tricks from this article. From seeding to harvesting, you’ll learn everything you need to know about growing herbs in a greenhouse.

What is herbalism?

Some herbs and spices have represented an important role in history. Thyme, for example, is a symbol of bravery. Some prehistoric rituals used basil for soul cleansing. The culinary and healing powers of various herbs have been recognized by nearly all populations and with varying customs.

Basil leaves in and out of a mortar and pestle with some basil essential oils in two small clear bottles

Herbalism applies to traditional therapeutic customs based on the application of plants and their essences. It is also known as phytotherapy or botanical medicine. It is the earliest form of the medical profession with a continuous culture that leads back to the origin of documented history.

Most prescriptions that are presently accessible to Western practitioners have a deep history as herbal treatments, including opium, digitalis, aspirin, quinine, and more. The constitutional situation of herbal ingredients varies from one nation to another. Make sure to ask for recommendations from doctors before adopting herbal medicines.

We can see herbs almost everywhere and sometimes take them for granted. Some herbs, like lemongrass, are even confused for weeds because most of them require little attention and grow easily. It will give elegance, scent, and of course an overflowing essence in your kitchen.

A greenhouse can help you extend your growing season and let you appreciate homegrown herbs at almost any time of the year. You can simply use the soil in your greenhouse floor or also beautiful pots and planters. You may store your container-grown herbs inside a heated greenhouse in winter.

Several herbs planted in pots placed in a kitchen

Give your greenhouse herbs a happy environment by growing them under optimum conditions. You can propagate annual and biennial herbs in greenhouses and perennial herbs from plant cuttings.

Benefits of herbs

  • Help with wound healing
  • Affordable nutritional supplement
  • Lowers blood sugar levels
  • Reduces bad cholesterol levels
  • Anti-inflammatory properties
  • Prevents Alzheimer’s
  • Prevents several types of cancer
  • Promotes healthy brain functions
  • It strengthens the immune system
  • It serves as an organic hair, skin, and dental care

Advantages of growing herbs in a greenhouse

You can make herbs available to you basically all year round. A greenhouse can also provide the perfect growing conditions for your herbs because you can control the elements and climate.

Sun protection

A greenhouse can give your herbs protection from extreme heat and sunlight in summer. You can create a shaded area in your greenhouse so that they won’t dry out too quickly. It is often easier to add a shade cloth to a greenhouse structure than somewhere in the garden.

Extending seasons

Growing herbs in a greenhouse in winter is a great way to extend the growing season year-round. Herbaceous perennial herbs usually die back throughout the freezing periods, but now they can be forced in your greenhouse for winter usage. They will continue growing out fresh shoots.


There are a variety of herbs can benefit from being placed into your greenhouse in freezing weather. Wrapping delicate and half-hardy herbs in bubble wrap to shield both roots and shoots can provide them security until the fresh growing season gets started. This is a good idea especially when their leaves start falling. Then when spring arrives, plant or move them back outside.

Green leaves with snow on it

Seeding & propagation

Plant herb seeds in a healthy condition with beneficial seed fertilizer. Once they have developed mature enough, they can be transplanted into different pots or outside.

You can cultivate annual and biennials in three ways. You can grow them from seeds, propagate them from cuttings or divisions. If you are just starting out, you may buy seeds or young plants at a garden center or another local place. If you already have plants, you might be able to collect seeds, to divide existing plants, or to use cuttings in order to increase your herb plants.

A clock placed on a center part of the table with yellow flowers behind

What are the things that we need to watch out for?


Research has revealed that ultraviolet rays from the sun, especially UV-B radiation, enhance the number of active essences in herbs. It stimulates their natural defense mechanisms, along with the production of essential oils and aroma. If you don’t get many daylight hours in winter, use a grow light to simulate the sun.

Humidity & watering

Herbs don’t like it dry. Your greenhouse should maintain a certain humidity and you should water your plants frequently. Remember that herbs need extra water throughout hot, breezy, and dry conditions. However, you shouldn’t overwater them. Keeping the soil moist is the best way to guarantee healthy herbs. Too much humidity and soggy soil can cause plant diseases.

Supply adequate water to moisten the area around the root at least six inches deep. Drip irrigation systems are cost-effective ways to water your herbs. This system avoids wasting water by utilizing it just to the root zone and limit disease by maintaining dry leaves.

Air circulation

Inadequate airflow decreases plant activity and may lead to difficulties with moisture and disease control. You can install fans in your greenhouse to distribute air evenly inside. Fans are usually installed to assist in proper airflow especially when venting is minimal.

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Shelves in a greenhouse with herbs and the text: How to grow herbs in a greenhouse


Perform cooling in two ways. First is passive ventilation, where the wind comes in and out freely through vents. However, this may not exactly cool down the greenhouse if the outside temperature is high. Then it’s basically just circulation hot air from one place to another.

Active cooling, on the other hand, is the forced air within the greenhouse. This involves coolers, such as the RSI Evaporative Cooler. The downside is the necessity of a power source.

Carbon dioxide

The carbon dioxide concentration is 350 ppm. It is an important factor for photosynthesis. Poor concentration can generate damaging herb growth.


If you want to grow your herbs year-round, you may need a heating system in order to keep a certain temperature in your greenhouse.

There are different kinds of heating systems for each greenhouse. A combination of air heating and ground heating is very effective. Take control over air temperature and relative humidity particularly throughout winter.


Do not over-fertilize your herbs. Follow soil test instructions and directions to understand how much fertilizer you need to apply. Do not put fresh manure as a top-dressing. You have to let it mature first in order to reduce the chance of harmful bacteria and overheating.

Brown Wood chips used as mulch


Mulching prevents weeds from spreading. Apply a 2-3-inch layer of organic mulch. Keep it away from the crown of your herbs. Another good thing is that it preserves moisture, so you will waterless.

Taking care of your greenhouse herbs

Take plenty of time to properly organize ​and arrange ​your ​herb garden. Remember that the demands of your greenhouse herbs are basically the same. Check out some of them below.


Maintain luscious and bushy herb plants by pinching 2 to 3 inches off the stem peaks. This promotes branching and fresh growth. If you want more leaves, simply pinch off any flowers that will appear.

A light blue pruning tool cutting a branch of a tree


Your herbs will grow best if you trim them regularly. Prune those dead stems of the previous year’s growth. Some perennial herbs may grow woody or thin after many years. Prune them back in spring by one-third or down to 4 inches off the ground before fresh growth starts. This promotes a more compact and full form.


If you grow your seedlings in seed trays or want to transplant herbs from a smaller pot into the ground, be careful to not hurt the roots.

Dig a hole about twice as wide as needed but not deeper than the current pot. Carefully pull the herb out. Plant the root ball into the hole and fill the rest with soil. Water the root zone properly to engage new growth.

A plant divided in the middle showing its roots ready to be re potted


Some perennial herbs like chives develop clumps. Thyme, for example, is spread by runners. You can dig and divide spreading and clumping herbs, especially in spring to produce more plants.


Produce woody herbs from cuttings especially in spring. Less woody herbs like mint, oregano, and basil will develop roots easily from cuttings. Take cuttings from healthy and disease-free plants. Do not cut from flowering herbs because the plant’s energy concentrates on flowering, not developing roots.

A gardener removing weeds using a rake


Make sure to inspect for weeds weekly. It is easier to remove them when they are smaller. Having a lot of weeds can draw more bugs which are harmful to your herbs. They are also a competition for nutrients.

Best greenhouse accessories for growing herbs

Improve the growing conditions for herbs by acquiring some of these accessories. It will make your gardening experience enjoyable and fruitful. We already have suggested some accessories above and here are some more to consider:

Seedling emerging from a green seed tray

Seed trays

This is a smart way to save space inside your greenhouse. Double the number of herbs you grow from seeds and cuttings. The great thing about using seed trays is that you will prevent damages when transplanting. This will result in higher yields.