Updated at: 21-10-2022 - By: Sienna Lewis

How many greenhouses have you owned in the past, if any? In a greenhouse, what is the ideal temperature for producing vegetables? This conversation is just one of several obligations to consider.

If you want to know how to cultivate fresh veggies from the farm to the table, you need to know the proper steps and instructions. Whether you’re a farmer or a gardener, you’ll find everything you need to know about greenhouse gardening on this blog.

What Vegetables Do Well In A Greenhouse?

Vegetables grown in a greenhouse may seem difficult to some gardeners, but it’s actually rather simple. Remember that the greatest veggies to grow in the greenhouse are ones that you can either consume yourself or sell to the public. If they can survive indoors, that’s even better.

Here are some of the best vegetables to have:

  • Peppers
  • Strawberries
  • Lettuce
  • Tomatoes
  • Beans
  • Peas
  • Cucumbers

What Is The Best Growing Temperature For Vegetables In A Greenhouse?

In order to keep the temperature steady in your greenhouse, you need to know that 85 degrees Fahrenheit is the ideal temperature for your plants to thrive.

What Is The Best Growing Temperature For Vegetables In A Greenhouse - Krostrade

As plant specialists will tell you, it’s critical to have adequate ventilation when caring for your plants. It is your responsibility to maintain a comfortable temperature in the greenhouse, even if it appears to be a great setting.

Although you can install electric or gas heaters as a backup source of heat, most of these greenhouses use the sun’s energy to heat the air within. On hot, sunny days, the building’s interior may easily reach temperatures of over 100 degrees Fahrenheit, making temperature control essential to the health of the plants.

Vents, such as the top vent that opens a hatch right in the ceiling or the side vents, as well as fans that whisk out hot air and welcome cooler air, are also necessary in greenhouses. You can choose between vents that open and close automatically or ones that open and close manually.

Manual systems are less expensive, but you must remember to open and close your vents throughout the day like you do at night. Those who aren’t at home throughout the day could find this added job burdensome, especially if the weather unexpectedly changes.

You should be aware that automatic ventilation systems are known to use sensors that activate the fans or heating systems when the temperature rises or falls below a certain threshold. Heating and cooling systems in homes should be comparable to this.

Can You Grow Vegetables In A Greenhouse Year-Round?

Gardeners enjoy the greenhouse because it allows them to get the most out of the available sunshine. Small, unheated greenhouses can help gardeners extend the growing season by producing the best yields for a wide range of veggies.

You should look for a greenhouse that can be used throughout the year. Heated greenhouses are ideal for year-round use, but they are rarely economical.

Late winter toward early spring

You’ll want to plant tough plants like cabbage and celeriac as soon as the weather gets warmer so that they’ll be ready to go out when it does. The proper germination can be ensured by using your heated propagator (if you have one).

You may be able to start seedlings of peppers, tomatoes, and other fragile plants in greenhouses that are heated.

Middle of spring

The optimal time to seed fast-growing fragile plants like cucumbers, pumpkins, squashes, and courgettes in a greenhouse is in mid-spring, which we guarantee. French beans, sweet corn, and melons are all acceptable additions. During the spring and early summer months, they are at their best. The heated propagator can also be used to ensure germination.

Planting peppers and tomatoes in greenhouses that are not heated is also an excellent idea. You can begin sowing basil indoors in order to transplant it to the garden in the spring.

Late in the spring to early in the summer season

Summer greenhouse plants can be grown into their final positions inside. Once the cold has passed, you can harden off and sow out young crops for your outdoor crops.

The middle of summer

Mid-summer gardeners dream of collecting melon, French bean, and cucumber harvests, among others. When summer harvests have finished, they may also include parsley and calabrese.

Late in the summer

You can sow lettuces, spicy salad leaves, tiny carrots, and more in the late summer, when your spaces permit, in time for the autumn sun. Use the heated greenhouses to get a jump start on your holiday potato planting this year!.


Plant lettuce in beds and grow bags for winter harvest in the fall after the spent summer vegetables have been removed from the garden. Calabrese, French beans and parsley can also be started indoors and allowed to grow to maturity.

For broad beans and peas, you can wait until the clay soil is more controllable early in the spring season before planting them out. Hardy lettuces and pea shoots can be grown in the spring and harvested indoors. Finally, transfer the herbs to pots so they can continue to produce for longer. If you follow the advice in this article, things will get better for you.

What Temperature Should A Greenhouse Be At Night?

It is important to keep in mind that the nighttime temperature must be between 32 and 75 degrees Fahrenheit. Depending on the type of vegetable you’re producing, you’ll want to keep the greenhouse temperature at a lower or higher level to get the best results. Flowers and branches may be more numerous and abundant in colder circumstances.

What Temperature Is Too Cold For A Greenhouse?

Maintaining a comfortable interior temperature is a must. Tender plants like citrus trees, half-hardy fuchsias, and pelargoniums prefer a minimum temperature of 45 degrees Fahrenheit, and the safest is 50 degrees Fahrenheit for greenhouse temperatures.

How Can I Heat My Greenhouse For Free In The Winter?

Here are the actions to follow in order to answer this question. Finding ways to heat the greenhouse without paying for it may be tough, but there are inexpensive ways to do so.

The Best Greenhouse Vegetables - What to Grow in Your Greenhouse - Essential Home and Garden

The cost of heating a greenhouse in the winter may outweigh the savings and benefits of owning one, even if the greenhouse itself is free. Thus, the little greenhouse, a rabbit hutch, composting hay, or dustbins are all fantastic ways to save money.

When you have this information, you can grow your crops in a greenhouse at the right temperature. Start working on it right now.

Optimal Greenhouse Humidity – Why ~80% Relative Humidity?

A crop’s ability to thrive is directly related to the amount of moisture in the air. In order to get appropriate humidity levels for their plants, most growers strive to do so.

The optimal relative humidity setpoint for most plants is around 80%. At this level, growth rates are highest for common greenhouse plants. At higher or lower humidity levels, plant physiological processes may slow down, leading to slower growth and lower quality output.

Most plants do best with a relative humidity level of about 80%. Common greenhouse plants’ growth rates peak at this level. Plant physiological processes may slow down at greater or lower humidity levels, resulting in slower growth and a worse quality product.

It is more important for growers to understand, control, and maintain humidity levels that are optimal for the crops they want to grow than it is to simply try to eliminate it.

Optimal Greenhouse Temperature – Why 18°C (64°F)?

An ideal temperature range for most greenhouse crops is 18-24°C (64-75°F).

Most greenhouses throughout the world use these temperatures because they are deemed ideal for most common crops. For this reason, producers rarely deviate from a temperature range that falls within this range because it typically results in slower growth and lower quality crops.

Humidity management is essential in greenhouses and indoor growth facilities. Uncontrolled humidity can cause serious difficulties and inefficiency in these environments. Crops grow more slowly, are smaller, and have inferior quality when they are exposed to unfavorable environmental circumstances.

Condensation can occur in any building if humidity levels are not properly controlled. Botrytis and downy mildew may quickly wreak havoc on a wide range of crops, including vegetables, cannabis, and more, if the free water is there.

Example of Water Extraction Rate Graph

Here’s a graph showing the new DG-12 EU unit’s water extraction rate at various temperatures between 12oC and 24oC (64oF – 75oF).

As the temperature and relative humidity rise, extraction rates increase.

The machine removes 48 liters of water per hour under ideal greenhouse conditions of 80 percent relative humidity and 18oC. When the temperature rises, the machine draws water more quickly.

DryGair Provides Optimal Humidity and Temperature for Common Greenhouse Conditions

For agriculture, DryGair is one of the few manufacturers of dehumidifiers with a sole focus on humidity control. At 18oC and 80% relative humidity, the units deliver the best possible humidity decrease. DryGair is able to extract more than 4 liters (1 gallon) of water per kWh because of this.

There are times of the year when DryGair units should be used in greenhouses and indoor cultivation as a solution:

  • When there is no way to heat and ventilate a building without also losing heat,
  • A uniform and continuous climate condition exists during the night – from dusk to morning (read more).
  • Humidity in the outside air is higher than that in the indoor environment (i.e. rain, humid seasons)

Various diseases can occur as a result of dewpoint condensation caused by increases in relative humidity. When the light outside is changing rapidly at night and dawn, DryGair’s humidity control system is designed to avoid these peaks.

High water extraction rate: DryGair is a horticultural humidity management instrument

  • As much as 13 gallons per hour (13 liters) at 18oC (64oF) and 80 percent relative humidity.
  • During the night, 576 liters of water are extracted (152 gallons)

All DryGair operational data is recorded at a relative humidity of 80% at 18Co (64Fo). At higher temperatures and relative humidity levels, water extraction speeds up.

The perfect temperature and humidity

While every plant is different, a greenhouse temperature of 80°F (27°C) is good for the majority of garden plants and vegetables. At this temperature, most plants will thrive. Humidity rises in direct proportion to temperature. The following graph compares greenhouse temperature and humidity at various times of the year:


Fifty-three degrees and eighty-three percent

90% of 61°F

The temperature was 68 degrees and the humidity was 91%.

A temperature of 86 degrees and a humidity of 95%

As a general rule of thumb, the temperature should be no lower than 80°F. Each of your plants should be checked thoroughly to see whether they are susceptible to illness or infection. In the case of crops such as tomatoes and melons, which require a lot of sunlight, you’ll want to keep your temperature higher. Do not exceed 90°F (32°C) or fall below 75°F (24°C) in general. Most plants can be kept alive and healthy if they are kept in this range.

Because these plants are grown in an artificial environment, they must be kept at the correct temperature. If you have a lot of plants, the temperature and humidity will rise quickly in this environment. Fortunately, there are various techniques to regulate the temperature so that your plants can grow.

Controlling the temperature and humidity

The amount of sunlight and the amount of air movement in a greenhouse affect the temperature. Because they trap the sun’s heat, greenhouses make it easy to heat up a room, but they also make it difficult to regulate the temperature in that room. It is possible, however, to control the temperature and humidity in a simple manner.

Ventilation is the most important thing to create. There are many ways to do this, including placing vents in the roof or simply opening the windows and doors to let in some fresh air. If you want to lower the temperature, you can also utilize air conditioning. During the winter months, use fans to draw in cold air and expel warm air.

It’s possible to fool the plants into believing they’re in a different season, depending on what you’re producing. Heaters and additional lighting can be used to mimic the sun’s rays during the winter months. Greenhouse timers, on the other hand, may make this process virtually automatic. It’s time to talk about the tools you may use to keep an eye on greenhouse temperatures and humidity levels.

Tools for greenhouse monitoring

It’s easy to maintain a greenhouse thanks to a variety of helpful tools. Despite the fact that they aren’t necessary, greenhouses are man-made environments that must be properly cared for at all times, but especially in the winter. That’s made a lot easier by these tools.

Greenhouse temperature alarm

Water damage, temperature variations, and power interruptions are all indicators that this alarm is monitoring for potential problems in the greenhouse. Some models even go so far as to notify you via text message if such an event occurs.

Greenhouse temperature control system

The heating and cooling options provided by this device are accurate and trustworthy for your greenhouse. Maintaining an ideal temperature all year round is critical. You can control the temperature regardless of the weather outside.

Greenhouse temperature sensors

The ability to automate greenhouses is one of their best features (pardon the pun). Sensors in the greenhouse monitor the temperature and can trigger vents on the top, side vents, and fans to maintain the ideal temperature. Depending on the sensor model, you may also receive an alert if the system fails or encounters an issue.

Remote temperature monitor

Maintaining an eye on day-to-day temperature fluctuations in the greenhouse is critical. It’s impossible to know how to grow your plants if you don’t know how hot it is where you are. When you use a temperature monitor, you can get a comprehensive picture of the temperature throughout a specific time period. You’ll be able to see the temperature at any time because it’s being recorded.

Keeping your plants at the right temperature and humidity is essential to their well-being. Growing veggies and plants year-round, automatically, and (nearly) hassle-free is possible for anyone using the right tools and strategies.

Continue reading if you’re interested in finding out how you may put your greenhouse to good use besides just producing plants.

A Guide to Plant Temperatures

The first step to figuring out the best temperature for your greenhouse is to understand that plants are broken up into four groups depending on how they tolerate the temperature.

There are four main categories of plants when it comes to determining the ideal temperature for a greenhouse.

In order for tender plants to thrive, they must be kept above 60 degrees Fahrenheit. They require at least eight hours of direct sunlight and can’t withstand any frost. ” Temperatures above 50 degrees Fahrenheit are ideal for the growth of these plants.

The ideal temperature range for semi-hardy plants is 50-55 degrees Fahrenheit. Light frosts don’t kill semi-hardy plants, but they do need at least six hours of direct sunlight each day to thrive.

This type of plant can also be referred to as semi-woody.

Plants that can survive in temperatures as low as 45 degrees are considered hardy. Some veggies even taste better after a light frost since these plants can withstand more severe freezing conditions.

Additionally, they require only 3 to 6 hours of direct sunlight a day. Overheating can even kill sturdy plants.

As a result, they may be categorized as woody plants rather than hardy ones.

A greenhouse obviously offers greater flexibility in terms of what plants you can grow and when, but the USDA plant hardiness zone chart is a useful reference nonetheless.

Use this map to determine which plants will thrive best in your area. According to the average annual minimum winter temperature, this map is divided into four zones. Here, you may locate yourself.

Temperature Growing Guide for Plants

Tender: There are plants that simply adore sunlight and will starve if they don’t receive enough. Tomatoes and cantaloupes are two examples of plants that are particularly vulnerable to pests and disease.

Warm temperatures and a lot of sunlight are ideal conditions for these plants. There is a germination temperature and subsequently a growth temperature. Temperatures that are ideal for sensitive plants can be seen on this chart.

Many other plants enjoy the light, but don’t require it to be quite so warm. Begonias, calla lilies, celery, summer squash, and cucumbers are all examples of these delicate plants. Take a look at these plants’ recommended temperature ranges.

Another option is to choose a plant that doesn’t mind the cooler temperatures and can even survive a little frost. Geraniums, hydrangeas, beets, carrots, and lettuce are all examples of semi-hardy plants. Here are some general temperature recommendations for those particular plants.

In the end, there are the hardy plants that can handle the cold and the frost. Frozen conditions are ideal for plants like yarrow; columbine; asparagus; broccoli; peas; and broccoli

Some of the hardy flowers don’t bloom in the winter, but they’ll survive the cold. Take a look at the following temperature recommendations.

Plants like asparagus that like 75 to 85 degrees Fahrenheit to grow are called hardy and flourish in freezing temperatures. There’s absolutely no chance of frost at that temperature.

Many plants enter a dormant phase during the cooler months, but something happens in the cooler temperatures that encourages their development until the warmer months approach.

Best Time to Plant-Based on Temperature

Even if you can control the temperature in your greenhouse, there are still excellent periods to plant particular crops.

Planting frost tolerant crops like spinach, lettuce, and broccoli in the winter and early spring is ideal. You won’t need to heat your greenhouse as much if at all if you utilize these plants, which can tolerate lower temperatures and frost.

You can also start the plants in your greenhouse and then move them outdoors when evening lows stay above 30 degrees.

Also, you may want to plant them outside when nighttime lows are over 30 degrees in your greenhouse.

Sun-loving plants should be planted in the late summer and early fall. Hot peppers, eggplant, and tomatoes all thrive in high temperatures. It’s not ideal if it’s too hot. Cooling things down with a ventilation system is possible.

When the weather begins to wind down, it’s time to start planting crops that like cooler temperatures. It’s a good time to grow kale, snow peas, and turnips. Furthermore, because these plants prefer lower temperatures, you won’t need to heat the greenhouse.

Greenhouse Gardening in Winter: What Plants To Grow in the Cold Season

Controlling Your Greenhouse Temperature

For now, you may be asking what can be done if your greenhouse temperature isn’t within the acceptable range. To help you out, here are some suggestions.

To begin, invest in a thermometer and use it to monitor the ambient temperature. Because it measures both temperature and humidity, this Amazon model is always a top pick of mine. When it comes to your greenhouse’s environment, you should always keep an eye on both.

In order to lower the temperature, you must construct a ventilation system as your first step. A ventilation system is an absolute necessity in any greenhouse. Ventilation is a must, even if you live in an area with a mild environment and don’t need to reduce the temperature.

A greenhouse ventilation system aids in cooling, humidity control, and air circulation. If you haven’t installed a ventilation system, your plants may already be experiencing issues.

Cooling your greenhouse with these other methods is also an option:

  • a cloak of darkness
  • Misters
  • Cooling via evaporation
  • Heating and cooling equipment that is portable
  • lining the greenhouse’s perimeter with taller, shadier plants

Depending on your budget, you can select the most cost-effective cooling solution.

This can be done by increasing the temperature of your greenhouse if the weather is colder. Here are a few suggestions.

  • Pile up the compost (puts off heat)
  • Barrels of water painted black and ready for use
  • Place it far enough away from plants so they don’t get dried out.
  • The use of vegetation as a cover for other plants
  • Infrared heaters (make sure you have a fan to circulate the heat)

As you can see, the ideal temperature for your greenhouse depends on the type of plants you intend to grow. You might plant one type of plant one season and another type another season. The beauty of a greenhouse is you can adjust the temperature to meet your plant’s needs.

As you can see, the ideal temperature for your greenhouse depends on the type of plants you intend to grow. Depending on the season, you might plant one sort of plant and another type the following year, etc. A greenhouse’s advantage is that you can control the temperature to suit your plant’s requirements.