A greenhouse can be a great addition to any garden, but what if you don’t get enough sunlight? Is it good enough to set your greenhouse in the shade?
As a whole, it’s inefficient to set a greenhouse in an area with less than 3 hours of sunlight each day. It’s impractical because not many plants will grow with this little amount of light. Partial shade with 3-6 hours of sun exposure is acceptable, but 6+ hours of sunlight is better for plant growth.
Below, I expand on this concept with helpful tips and a list of shade-tolerant plants. But first, a brief note on shade …
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What Does Shade Mean in the Gardening World?
If you’ve been a gardener or plant owner for a while now, you’ve probably come across the terms’ dapple shade’, ‘partial shade’, ‘dense shade’, and ‘deep shade’. Some are used interchangeably, and some have different meanings altogether. But generally, this is what their definitions are:
- Partial/dapple shade refers to 3-6 hours of sunlight.
- Deep/dense shade usually means less than 3 hours of sunlight.
Light is crucial for a plant’s development because they need it for photosynthesis to make food. So most plants can thrive in partial shade, but they do best in full sun, i.e., more than 6 hours of sunlight. There’s more science that goes into it, but we’re not about to open up a textbook Biology lesson on that today. Instead, we’ll focus on how exactly this fundamental knowledge applies to your greenhouse set-up.
Is it a Big Deal if a Greenhouse is Placed in The Shade?
A lot of guesswork goes into building a greenhouse at home, and this is one of those questions that definitely comes up. As mentioned in the introduction, a deep/dense shade location is not a really good place for the building. You lose out on most of the benefits of having it in the first place and instead deal with problems like the following:
- Not enough heat is absorbed to keep the structure warm at night.
- Inadequate sunlight delays/stunts plant growth throughout the seasons.
- Limited plant choices to grow due to heavy shade.
- Lack of air circulation contributes to stagnant air, which may promote disease growth if the area is heavily packed with tall structures and plants.
You can add a grow light, heating, and ventilation system, but they become an added cost to your overall maintenance. It’s simply not cost-effective. The only upside you’ll have is protection against critters and pests.
But in a partial/dapple-shaded location, you have better odds at making the most of your greenhouse. With respect to the previous section, you’re only getting about 3-6 hours of sunlight in this situation. Luckily, there are LOADS of plants you can grow with this amount of light. More on this in the next section. You can also use the place as a propagation station for cuttings and display/storage for flowering plants.
If you live in cool climates or areas with cold nights, you must add a heating system. The heat retained in the building is often not enough when you have it situated in a partial/dapple-shaded area. So it’s better to supplement it with a heater to keep your plants warm and prevent frost/cold damage. This is also helpful if you intend to use your greenhouse to extend the season or grow in winter.
A ventilation system is optional because you can simply open the windows, let the air in, and get rid of accumulated heat in the greenhouse. But it’s a worthwhile investment if you have a growing plant collection and if you’re gardening in the winter. You can read this Winter Gardening article for more information if you’re interested.
There’s also the option of adding grow lights if you really want to grow sun-loving/fruiting plants like tomatoes and squash. Theoretically, it is possible and has been done many times. However, the upkeep is costly, as I’ve said.
Where possible, it’s always better to place your greenhouse under full sun. You don’t have to add other systems because you’re using the available natural resources already at your disposal. So before building one in your home, decide whether it’s worth all the trouble to grow the plants you want.
What Are Some Plants I Can Grow in a Partially Shaded Greenhouse?
If you’re still set on growing plants in your partial/dapple-shaded greenhouse, here are some that will grow with 3-6 hours of sunlight:
| Shade-tolerant plants (2-5 hours of sun) | Sun-loving plants (6 hours of sun) |
| Lettuce | Onion |
| Spinach | Garlic |
| Radish | Endive |
| Arugula | Turnips |
| Kale | Carrots |
| Cress | Broccoli |
| Radicchio | Cabbage |
| Swiss chard | Potatoes |
| Cilantro/coriander | Hardy kiwi |
| Mustard greens | Alpine strawberry |
If you’ll notice, these are primarily leafy and root vegetables. They don’t require much sun as fruiting/summer vegetables like eggplants and peppers, making them relatively easy to grow with limited sunlight. Some also develop pretty quickly, allowing you to harvest the plant multiple times a year.
However, remember that the listed plants don’t all grow at the same rate and will have different needs, which may make it tricky to manage them. I recommend setting them in groups of similar watering frequency for a more efficient care routine. Here’s a section on grouping by watering needs in this food garden article that explains it further.
It’s also worth noting that some plants, like lettuce and cabbage, shouldn’t be placed next to each other. This is called companion planting, where you selectively put two plants together to benefit their growth and put others far away. This is especially important if you’re growing plants in the same container or in-ground. You can find out more about good and bad group plantings in this article to help you out.
Helpful Tips on Maintaining a Partially Shaded Greenhouse
Here are a few things to keep in mind when setting up your greenhouse, whether in partial shade or not:
- Place your greenhouse facing south, where it’ll receive more sun, provided there are no large structures or trees to obstruct sunlight. Setting it to the east may be best if you live somewhere warmer.
- Pay attention to the changes in sun exposure throughout the day and different seasons. This will give you an idea of where best to set your greenhouse, so you maximize more light for your plants’ growth. You should also note down tall structures and trees that may give shade.
- Position your greenhouse at least 30 feet away from growing and established trees. Fallen branches may damage the structure, and underground roots may make the ground uneven. Though some tree species don’t grow too large or spread their roots wide, it’s better to err on the side of caution anyway.
- Place a fence around the greenhouse or a windbreak hedge to protect it from strong gusts. Typically, picking a spot where the structure won’t be blown away is sufficient enough. But it doesn’t hurt to add some protective elements to prevent damage to the building.
- Ensure the ground is well-draining, flat, and even for the greenhouse. Don’t put it on a slope unless you want to go soil surfing when a landslide happens.
- Place the greenhouse near water and electricity resources, preferably closer to your home, for easier access. You don’t want to carry heavy items to and back to the building, much less hike there. Keep things simple and easy for yourself so it doesn’t become a chore to do gardening.
Frequently Asked Questions about Greenhouses
It’s essential to place a greenhouse in the sun to maximize light exposure for the growing plants. But if less sunlight is needed, use shade cloths to cover the windows. Placing it in the shade may not only limit your plant choice but also doesn’t allow you to efficiently use the building for its intended purpose.
A location with 6+ hours of sunlight is appropriate for most greenhouse needs. However, a partial shade with only 3-6 hours of light is doable. But it won’t allow fruiting vegetables like tomatoes to grow well. It often comes down to the specific plants you intend to grow in the building. But if it’s not a problem, a partial shade location will do.
Placing a greenhouse in the south or east direction with no tall buildings or trees to obstruct light exposure is the ideal location for a greenhouse. It’s even better to have it within walking distance to the house, electricity, and water resources. Sometimes, this may not be feasible for some people, which is fine. This is not a hard and fast rule to follow because you can always supplement your building with things like grow lights if there’s a lack of sun. But as long as you keep it 30 feet away from trees, it’s good enough.
It’s advisable to use gravel or concrete flooring in a greenhouse. This prevents foot traffic on in-ground planting, which may compact the soil. It also makes clean-up easier and prevents weeds from growing. But you can also opt out of applying flooring and keeping it all natural, so long as the ground is well-draining.
A heating system helps maintain warm temperatures in your greenhouse at night, especially in winter. However, it’s usually not needed if the building is in a sunny location. Some also use bubble wrap to keep the heat accumulated during the day inside the structure. This is less of a worry for those living in a warmer climate. But those living in colder areas may want to invest in a heating system in their greenhouse if plants are stored there throughout the winter.
Placing the greenhouse in a sunny location is enough to naturally heat up the building. It will trap the heat it absorbs all day, often keeping the structure and plants warm through the night. However, this may not be possible if it is in the shade.
There may be a few reasons why your plants are dying in your greenhouse:
1. It’s too hot. Some plants are heat-sensitive and may start crisping up and wilting due to the intense heat accumulated in the greenhouse. Open up the windows or vents to allow some cool air in.
2. There is no proper ventilation system set in. No air circulation may be causing stagnant, hot air in the building. It’s crucial to allow airflow to keep the temperature constant and cool the greenhouse for your plants.
3. There is no heating system to keep the plant warm during cold nights or during a frost. In winter, most plants go dormant and are best stored in warm areas to protect them. Once the temperature drops too low, they may suffer from cold damage, making them unlikely to recover.
As a whole, tomatoes won’t develop well and bear fruit in a shaded greenhouse. However, this may be possible with an LED grow light system installed in the building. The downside is that it may be pricy and too much of a hassle. Instead of relying on natural sunlight, you must purchase additional items to help the tomato plant bloom.
Final Words
All in all, placing a greenhouse in the shade may be doable, but it comes with limitations. The good news is you can definitely work around it and make the best of what you can grow. But where possible, total sunlight exposure is the way to go. Happy planting!
References:
- The Hobby Greenhouse – Oklahoma State University. (2017, April 1). Extension.okstate.edu. https://extension.okstate.edu/fact-sheets/the-hobby-greenhouse-2.html
- A Small Backyard Greenhouse for the Home Gardener | NC State Extension Publications. (n.d.). Content.ces.ncsu.edu. Retrieved August 23, 2022, from https://content.ces.ncsu.edu/a-small-backyard-greenhouse-for-the-home-gardener
- LED Grow Lights for Plant Production – Oklahoma State University. (2017, April 1). Extension.okstate.edu. https://extension.okstate.edu/fact-sheets/led-grow-lights-for-plant-production.html
- Gardening in the shade. (n.d.). Extension.umn.edu. Retrieved August 23, 2022, from https://extension.umn.edu/planting-and-growing-guides/gardening-shade#shade%3A-different-light-levels-1218963
- “Shady Characters – Edibles That Will Grow in the Shade.” (n.d.). Transylvania.ces.ncsu.edu. Retrieved August 23, 2022, from https://transylvania.ces.ncsu.edu/2020/03/shady-characters-edibles-that-will-grow-in-the-shade/
- Top Edible Plants and Herbs for Shade Top Edible Plants and Herbs for Shade Center for Urban Resilience Repository Citation Repository Citation. (2021). https://digitalcommons.lmu.edu/cgi/viewcontent.cgi?article=1059&context=urbanecolab-module10
