Greenhouse gardening opens up possibilities for those wanting to grow vegetables year-round. It provides protection from harsh weather, extends growing seasons, and gives plants a more controlled environment.
For new or experienced gardeners, understanding how to grow vegetables in a greenhouse can be rewarding in yielding fresh produce even through winter months.
With the right approach, you can maximize your greenhouse space to grow everything from leafy greens to tomatoes, peppers, and herbs, making each season fruitful.
In this article, we share 6-steps we've learned from our customers to growing vegetables in a greenhouse.
Let’s dive in.
Step 1: Planning Your Greenhouse Garden
The first step in learning how to grow vegetables in a greenhouse is planning the types of vegetables you’ll grow and how they’ll fit in the space. To choose the right plants, consider your personal preferences and climate.
- For example, leafy greens like spinach, lettuce, and kale thrive in cooler weather and do well in fall or early spring.
- On the other hand, heat-loving plants like tomatoes, cucumbers, and peppers can grow in the summer or with added greenhouse heating in cooler months.
When planning, map out the layout to best use limited space. Tall plants like tomatoes should be placed near the back or sides, where they won’t cast shadows over shorter crops like basil or lettuce.
Raised beds or planter tables can make planting and harvesting more accessible, while vertical gardening options like trellises can help maximize your square footage.
At this stage, decide whether to use containers or plant directly in the ground. Container gardening offers more flexibility and helps isolate plants, reducing the spread of pests or diseases.
Step 2: Selecting and Starting Seeds
When selecting seeds, think about the growing conditions within your greenhouse. Opt for seeds suited to the temperatures you can maintain.
- Peppers and eggplants thrive in warmer, consistent conditions,
- Hardy greens can tolerate fluctuations.
Starting seeds in trays or on a dedicated propagation table lets you easily manage seedlings’ watering, warmth, and light needs before transplanting them to the main beds.
Choose varieties that mature quickly for early crops:
- Some examples are radishes or arugula.
- Plan to start earlier for more extended crops like tomatoes or peppers to allow for a longer growing season.
Using heating mats can be beneficial in cooler months, helping to provide the warmth needed for seed germination. Once seedlings are sturdy, transplant them into their designated spots, ensuring they have enough room to grow and spread.
Step 3: Temperature and Light Management
Temperature control is key to successfully growing vegetables in a greenhouse. Vegetables need consistent warmth, especially at night.
- Installing a thermometer helps you track temperature changes, and adding ventilation, like fans or roll-up sides, lets you moderate excess heat on warmer days.
- Consider adding a small heater or thermal mass (like water barrels) to help stabilize nighttime temperatures in colder months.
- Light management is equally crucial. During the shorter days of winter, supplemental lighting may be necessary to keep plants growing optimally.
LED grow lights are a popular, energy-efficient option that mimics sunlight and supports growth. Choose lights suited to the type of vegetables you’re growing, as fruiting plants (e.g., tomatoes and peppers) often require more light intensity than leafy greens.
Step 4: Watering and Humidity Control
Maintaining the right moisture levels in your greenhouse is essential to prevent common greenhouse issues like mold, mildew, and root rot. Vegetables generally need consistent watering, especially during warmer periods or when bearing fruit.
For ease of installation, consider installing a drip irrigation system that delivers water gradually and evenly to the root zones, preventing the soil from getting too wet or too dry.
Humidity is another crucial factor in greenhouse gardening. During colder months, when the greenhouse stays closed to retain heat, humidity levels can rise, creating a breeding ground for fungal diseases.
Use a hygrometer to monitor the humidity, aiming for 60-70% levels for most vegetables. If humidity becomes too high, open vents or turn on fans to increase airflow and maintain a healthier environment for your plants.
Step 5: Managing Crop Rotation and Companion Planting
Crop rotation and companion planting are excellent ways to promote healthy plant growth and prevent the spread of pests and diseases.
Crop rotation involves changing the location of plant families each season, which helps avoid soil depletion and disrupts the life cycles of pests that may target specific crops.
For example, if you grow tomatoes in one spot this season, plant legumes or leafy greens in that area the next year to balance soil nutrients and reduce pest buildup.
Companion planting is also beneficial for greenhouse gardening. Strategically pairing certain plants can promote natural pest control and enhance plant growth.
- Basil planted alongside tomatoes can improve the tomatoes’ flavor and help repel aphids.
- When grown near peppers or cucumbers, marigolds can deter many common pests.
Use a planting chart to identify compatible and incompatible plants, and try experimenting with different combinations to find what works best in your greenhouse.
Step 6: Extending the Growing Season with Quick Crops
A greenhouse gives you the advantage of growing vegetables earlier in spring and later in fall. Still, you can maximize this benefit by planting quick-growing crops between longer-season vegetables.
Fast-growing crops like:
- radishes,
- spinach,
- and arugula can mature in as little as 30-40 days.
This allows you to harvest them and free up space for new plantings.
Succession planting is another technique for continuous harvests. After harvesting a short-season crop, replant with another quick crop or a seasonal vegetable.
For example, after harvesting early radishes, you could plant green onions or lettuce in their place. By staggering these plantings, you’ll enjoy a steady stream of fresh produce throughout the year, using your greenhouse space fully.
Troubleshooting Common Greenhouse Challenges
Greenhouse gardening is rewarding, but it also comes with its own set of challenges. Managing pests, temperature fluctuations, and potential plant diseases can sometimes feel overwhelming.
- Pests like aphids and spider mites may still exist, even in controlled environments. To manage these, consider using insect screens on vents and doors, sticky traps, and companion planting with pest-repellent plants like marigolds.
- For added protection, inspect plants regularly, especially the undersides of leaves, where pests often hide.
- Temperature spikes during unseasonably warm days can stress plants, so good ventilation is crucial. Automated vents or fans help regulate temperature, reducing the need for manual adjustments.
To prevent fungal diseases, monitor humidity levels and use fans to ensure steady airflow. Consistent monitoring and a proactive approach can prevent or quickly address many greenhouse problems.
Ready to Start Growing Vegetables Today?
Growing vegetables in a greenhouse is a fantastic way to enjoy fresh, home-grown produce throughout the year, no matter the season.
By taking the time to plan your space, choose the right crops, and manage environmental factors like temperature, light, and humidity, you can create a thriving greenhouse garden.
Explore our DIY kits if you’re ready to take your gardening to the next level. Investing in a quality greenhouse tailored to your needs can make all the difference, offering a stable foundation for every season.
Why Nova Greenhouses?
- We handpick high-quality greenhouses from the best brands in the world.
- Our team works hard to find extraordinary backyard greenhouses at reasonable price points.
- We exclusively source premium products made from the finest materials.
- Our team tests every greenhouse to guarantee strength & durability.
- We have a vast shipping network that reaches every corner of Canada & the USA.
- Our top-rated customer care team is available 7-days a week to answer any questions.