Okay, you have your first greenhouse and ready to grow some plants. Here is a list of items you need to be aware of before starting. A simple mistake early on will most likely carry on until the plants, if still living, leave the greenhouse.

Choose the Right Location:

Place your greenhouse in an area that receives maximum sunlight. South-facing locations are generally ideal. Ensure good air circulation around the greenhouse.

Select the Right Greenhouse

Choose a greenhouse with good insulation to retain heat during cooler seasons. Consider the size carefully; it should provide enough space for your plants and allow for proper air circulation.

Growing media

Starting Seeds

Starting seeds in the greenhouse in the early months is a difficult task. The temperature swings from 90 degrees on a sunny day and you will struggle to maintain a consistent temperature at night. Even with the use of heat pads I don’t recommend attempting to start seeds in the greenhouse. I have a heated grow bench in my basement that keeps a consistent temperature and provides ideal growing conditions for germination. Any sunny place inside your home will work but some seeds need light to germinate and using a plant light will increase your success.

Watering

There is a fine line between providing the right amount of water and over watering. It’s best to keep your plants on the dry side but remember a bright sunny day can easily fry them. Also, if you use hot air heat they can dry out at night. You should only water in the morning and if it’s a cloudy day avoid watering. When plants are small I use a small water bottle with small holes drilled in the cap. Seedlings need to be kept moist at first but not wet. Over watering will not encourage plants to grow roots and soil born disease to spread.

Install a drip irrigation system or use soaker hoses to provide consistent and efficient watering. Be mindful of humidity levels; avoid overwatering, as this can lead to fungal issues.

Ventilation

Perhaps the biggest mistake made from the beginner is not realizing how important ventilation is. Even on a cold day, fresh air must enter, and fans are needed to move air around. It could be hard to find the balance of temperature control and proper ventilation but it is the difference between success and failure. I find it is better to have good ventilation than a warmer temperature. I have better luck leaving windows open on a cold sunny day then trying to keep it warm to encourage plant growth. If your greenhouse has condensation on the inside, you don’t have enough ventilation for your plants. Again, I cannot stress enough that it is better if your greenhouse is 50 degrees with the window open than 90 degrees with it closed.

Invest in a good ventilation system to regulate temperature and humidity. This is crucial to prevent overheating, especially in the summer. Use shade cloth during hot months to protect plants from excessive sunlight.

Use a hygrometer to monitor humidity levels. Proper humidity is essential for certain plants.

Fertilization

Regularly fertilize your plants with a balanced fertilizer. The controlled environment of a greenhouse may necessitate more frequent feeding.

Proper Plant Selection

Choose plant varieties that thrive in greenhouse conditions. Rotate crops to prevent soil-borne diseases.

Seasonal Considerations

Adjust your greenhouse conditions based on the seasons. For example, you may need to add heating during the winter. Remember that each type of plant may have specific requirements, so it's essential to tailor your greenhouse management to the needs of the plants you are growing. Regular observation, attention to detail, and timely adjustments are key to successful greenhouse gardening.

Pest Management

Monitor for pests regularly, as the controlled environment can make it easier for pests to thrive. Consider introducing beneficial insects like ladybugs or predatory mites to control pests naturally.

Support Structures

Install trellises or stakes for climbing plants to support their growth. Ensure that the greenhouse structure can withstand the weight of plants and any additional support structures.

Post season cleanup

Once the plants are out of the greenhouse, it is essential to clean your greenhouse before the summer heat sets in. I also make sure everything I stored in the greenhouse is clean. Good housekeeping is essential to your success.

Check for and repair any leaks in the structure promptly.

Typical first 4 years of a newbie

• If you have a good first year, you will only loose about 10 percent of your plants.
• The second year is often worst because bugs and disease (that you did not notice the first year) are waiting for you and ready to kill off more plants.
• By the third year you should be aware of most of the gotchas and should have a plan. If no plan, get ready for some more misery.
• The fourth year should be profitable or there will be no fifth year.

Hit the ground running the first year.

• Greenhouse is a microclimate that will quickly spiral out of control if not properly monitored.
• Forget anything you know about gardening because little will apply in the greenhouse.
• You must check your greenhouse at least three times each day.
• Do not over water especially on cloudy days.
• Make sure you have enough ventilation. If your greenhouse feels tropical, you need more ventilation.
• Try to keep things on the cool side, warmth will bring bugs and disease.
• Plants are close together and insect infestation will spread like wildfire. These bugs will also spread plant disease. You need to treat insects on a regular interval whether you see them or not. Never let your guard down because things are looking good.
• Instead of using a sprayer, use a fogger so that everything is treated. You need to push treatments by air not by spray. Fog at night and fill your greenhouse with mist so that every bug is dead by morning. Follow up in 7 days to ensure any hatched egg is killed off.
• Always add small amount of fungicide when treating for insects.
• Do not waste time caring for sick or misfit plants, throw them away because nobody will buy them, and they will infect others.
• To make money, you must control heating cost. Do not be afraid to let nighttime temperature get into the 40s once plants are established.
• Make sure you have fans always moving air unless fogging.
• To make money, every plant needs to be perfect and uniform height and width. It will take years to prefect, but nobody wants a 6 pack of plants all different sizes. Every plant needs to be the same.

Conclusion

Growing plants in first couple of years in the greenhouse was tough. If it could happen it did and everything I discussed in this article happened to me. At one point I figured I could buy nicer plants cheaper then grow them. But once you get successful your return on investment works in your favor. Not only can you grow plants you cannot find in the store, the joy of starting your gardening season in January is worth every penny.