The ultimate goal of any gardener is to constantly produce food year-round. A helpful tool in this endeavor is a greenhouse. The next question, then, is can you grow tomatoes all year in a greenhouse?
Can you grow tomatoes all year in a greenhouse: Tomatoes are an excellent plant to grow in a greenhouse. By controlling the air temperature so it is above 60 degrees Fahrenheit and providing at least 14 hours of light for your plants, you can ensure they grow properly, even if it is the middle of winter. Tomato plants don’t need bees to pollinate their fruit and as long as you regularly add fertilizer, you can grow large, delicious tomatoes at any time of the year.
How do you grow tomatoes in a greenhouse all year?
Even though you can grow tomatoes at any point in your greenhouse, they still need the right temperature to start with. While some areas may be warm enough inside the greenhouse on their own, other areas may need to supplement the temperature.
If your greenhouse is warm but not warm enough for tomatoes (at least 60 degrees Fahrenheit) then you will have to add a grow light or a heat mat. Hopefully, your greenhouse will have an electrical element to it but if not, you can start your tomato seeds indoors and transplant them to your greenhouse when they are larger.
Even though there is no shortage of tomato seed packages at your local gardening center, you actually want to start with seeds that are specially created for greenhouse growing. While you can use general tomato seeds, specialized ones will be easier to grow in your greenhouse.
Greenhouse growing is all about containers. You need the right kind of soil mixture because your tomatoes won’t be in the ground.
Look for nutrient-rich soil that is made for greenhouses. It should have a mix of organic matter in it.
Always use new soil when growing tomatoes in your greenhouse. Tomatoes are known for using a lot of nutrients, so last year’s soil won’t be able to sustain a new crop of tomatoes.
Finally, you will want to add an extra source of calcium, such as bone meal to your soil. Tomatoes can often suffer from bottom-end rot, and extra calcium will minimize this risk.
Even though a greenhouse is a contained environment, there might be issues present in it. Always wipe down your surfaces with a solution of diluted bleach to ensure no diseases spread from plant to plant.
Look for any insect issues, such as white flies, inside your greenhouse. Treat any infestations as these pests can quickly ruin your crop.
In order to properly grow tomatoes all year long in a greenhouse, they need exposure to light. Obviously, this is hard to have in the middle of winter.
For more northern areas, you will need to invest in a light source to grow your tomatoes in the winter. Luckily, there are plenty of options for greenhouse lighting that is energy efficient. You can even look for second-hand lighting systems to save money.
Ideally, you want to expose your tomato plants to 16 hours of light per day.
Tomatoes are heavy feeders and even if you start with nutritious soil, you will need to keep adding more fertilizer as they grow. Always use a fertilizer that is made for tomatoes as a general one won’t work.
Fertilizers usually have three numbers on them, which refers to the ratio of nitrogen, phosphorus, and potassium. You want a fertilizer that has a higher number for potassium and a lower number for nitrogen.
After your tomatoes start to grow their fruit, you should start to add fertilizer to the soil as the plants will be putting a lot of energy into the tomatoes.
Continue to add fertilizer to your tomato plants every one to two weeks until you have picked all the tomatoes.
First, make sure you know what color your tomatoes will end up being. While red is the most common color, some will be orange and there are even varieties that are purple or almost-black.
Tomatoes ripen quickly, so once they start to change color from green, check on them every day or two.
In addition to color, check for firmness. You want the tomatoes to be firm but not hard. Too squishy and they are over-ripe.
You can also give your tomatoes a quick smell. The stem should smell a bit sweet.
When your tomatoes are ready for harvest, gently rotate the tomato so that it naturally breaks off at the stem. If you’re worried about damaging the tomatoes, you can also use scissors. Just make sure they are completely clean or you could spread the disease.
Tomatoes will last for three to five days if you leave them at room temperature. You can also store them in the fridge for five to seven days.
Factors that may affect tomato growth in your greenhouse
Basic greenhouses can be hard to control the temperature. To have the best success possible when growing tomatoes in the winter, you will need to upgrade your system to include electricity, a heater, and a light source.
The ideal temperature for tomatoes is between 60 and 90 degrees Fahrenheit. Make sure there is a thermometer in your greenhouse so you can adjust it as needed. In particular, pay attention to the temperature at night as it too must be above 60 degrees.
How many plants do you plan on growing? Watering by hand is fine for a few tomato plants but if you have an extensive setup, having an automated system is much better.
The best way to water tomatoes is to do so slowly and deeply. A drip watering system is ideal and easy to install.
The deeper the water can penetrate into the soil, the deeper the roots will grow, which will make for a stronger plant. If you hand water, it might not be enough for the tomato plant.
Remember that tomatoes grow. Each variety is different but plants can be quite large and bushy. While you can always move tomatoes around if they become too large for the area, it’s better to plan ahead of time.
Furthermore, tomato plants need a support system. Be sure to install a trellis or wire cages so your plants don’t topple over. Have this ready before the plants start growing so that you don’t interfere with the fruiting process.
Pests and diseases
A greenhouse might be a more controlled area than your outside garden but it is still susceptible to pests and diseases. This is especially true if you don’t engage in regular cleaning.
Before you plant any new crop in a greenhouse, first make sure there are no diseases on anything that is still growing. If there is, these diseases can quickly move from one plant to another, ruining all your hard work.
Constantly be on the lookout for insects in your greenhouse. While some are fine to have, others can lay eggs and start to eat your plants.
How long can a tomato plant live in a greenhouse?
We mostly think of tomatoes as annual plants because they die off once cold temperatures hit. But what if they aren’t exposed to winter conditions, such as with a greenhouse?
There are two types of tomatoes, determinate and indeterminate.
Determinate tomato plants will grow, produce fruit, and then eventually die, no matter what temperature they grow in. This all happens within a six to an eight-month timeframe.
On the other hand, indeterminate tomato plants will grow, produce fruit, and then will keep repeating the cycle. You can have indeterminate tomato plants that live for up to three years in your greenhouse.
There are pros and cons to each category of tomatoes so you should do your research ahead of time. If you love tomatoes and always want them available, indeterminate plants are ideal. However, if you want to rotate your crops and have enough space for other plants in your greenhouse, then determinate varieties are a better option.
Can you grow tomatoes in a greenhouse in the wintertime?
Yes, you most certainly grow tomatoes in the wintertime. The key is having the right temperature.
Tomatoes will only grow if the temperature is at least 60 degrees Fahrenheit. If it is too cold in your greenhouse, then you will need to supplement with a heating pad or grow light to reach that temperature.
Do tomatoes need bees to pollinate?
One reason that tomatoes grow so well in a greenhouse is that they have the ability to self-pollinate. This means they don’t rely on bees or other insects to transfer pollen between flowers.
Greenhouses are sealed off, so bees have a very hard time getting in. With tomatoes, you don’t have to worry about pollination.
Tomatoes are an overall easy plant to grow and are well-suited for growing in a greenhouse. If you have the right temperature and enough light in your greenhouse, you can grow tomatoes all year long.