Top 7 Greenhouse Gardening Mistakes to Avoid

Seeing your plants grow and thrive is a very rewarding experience, especially when you’re cultivating them correctly. When it comes to the best ways to grow in a greenhouse, whether it be plants, herbs, fruits or vegetables, you’ll want to make sure you bear in mind the greenhouse gardening mistakes to avoid.

Both professional and beginner gardeners still make mistakes, particularly when it comes to greenhouse gardening. By reading this article, we’ll help you to avoid these common pitfalls that can affect your greenhouse growing conditions.

Let’s get started!

Greenhouse Gardening Mistakes #1: Choosing the Wrong Greenhouse Building

Greenhouses serve one purpose; this being to aid in the cultivation of plant life.

So when it comes to investing in the ideal greenhouse, you’ll want to make sure your hard-earned money won’t be put to waste. Our outdoor experts suggest investing in a higher-quality, more robust type of greenhouse.

They may cost more upfront, but they’ll also guarantee a stronger structure that will last much longer. Plus, your return on investment can be offset in just a few years from your savings on fresh produce.

It will be to your advantage if you’re familiar with the different types of greenhouses available in the market. To help you reap that benefit, we’ve compiled a list of greenhouses which will best suit your plants.

Wooden Greenhouses

Wooden Greenhouses

Thanks to the natural insulation properties of wooden greenhouses, they make the overall building structure an environmentally controlled one. Perfect for the summertime, timber can absorb the rays during daylight hours and hold the heat at nighttime.

This type of greenhouse is a perfect choice if you plan to keep your harvest warm and protected from the frost throughout the colder months as well.

Metal Greenhouses

Metal Greenhouses

What makes metal greenhouses a superior choice when compared to their wooden counterparts is the aluminium frame that provides a solid construction base, making the entire building load-bearing.

What’s more, metal greenhouses are lightweight, easy to handle and manoeuvre. And there’s more, they’re maintenance-free and can be used for an extended period.

Polycarbonate Greenhouses

Polycarbonate Greenhouses

Polycarbonate greenhouses may be the cheapest option, but did you know that they’re also the most durable type of plastic greenhouses?

A polycarbonate greenhouse is thicker than glass, and offers more efficient light diffusion when compared to standard glass. Growing your greens in this greenhouse will offer them with equal light and ultimate protection against radiation exposure with its natural ultraviolet filter.

Greenhouse Gardening Mistakes #2: Choosing The Wrong Location

Sunlight is crucial for any kind of growing. However, most greenhouse gardeners tend to forget to factor in daylight when they begin to move their gardening into a greenhouse.

Our advice is to make sure your greenhouse location receives sufficient sunlight. By doing so, the maximum exposure to the sun will encourage and stimulate the growth of your crops.

Another thing to consider is paying attention to the objects that will block the sunlight, such as trees, buildings or your neighbour’s house. Setting the base near trees or large bushes could also lead to issues from overhanging branches. If that’s the case, it’s best to cut the branches before they come into contact with the building.

When picking the ideal location, here are the things you need to keep in mind:

  • Plant in a sunny spot – Most vegetables need at least 6 hours of direct sunlight a day. The more sunlight your veggies receive, the better they taste!
  • Plant in a stable environment – Avoid planting them in places that are prone to flooding or excessive dry weather.

Greenhouse Gardening Mistakes #3: Overlooking the Importance of Shade

Due to different wavelengths of solar radiation, your greenhouse can heat up. If that happens, the air temperature, as well as the leaf temperature, will rise. To prevent heat damage and reduce how much water your plants will require, shade cloth can be paired with the proper ventilation.

And while other plants can thrive in sunlight, it’d be best to prevent them from getting too much exposure. Using trees or other means of shade, such as a shading sheet for greenhouses, can increase the odds of survival for both delicate and sturdier plants.

Greenhouse Gardening Mistakes #4: Failing to Ventilate

Not properly ventilating your greenhouse is a common mistake

Opening the windows in your greenhouse doesn’t mean the building is properly ventilating. The air needs to flow through as plants tend to be sensitive when it comes to temperature.

Hot temperatures can cause them to wilt, while cold temperatures can cause them to stop growing, producing, or even deep freeze. They also can be prone to extreme swings in temperature.

To balance out your greenhouse’s temperature, ventilation is key. Having adequate ventilation will allow hot air to escape, while allowing the cold air in – and vice versa – thus maintaining an even, optimum temperature.

Greenhouse Gardening Mistakes #5: Watering Too Much

Watering your plants too much is a common greenhouse garden mistake

While tending to and watering your plants can make you feel relaxed and at the same time, get you moving, you need to be careful when watering them. It’s easy to under or over-water plants, due to the humidity levels.

Many beginner gardeners tend to over-water their plants. Watering them every day will only encourage your plants to set very shallow roots. Not only that, but this also can lead to mould growth, thus weakening the plants and inviting all sorts of pests, bugs and other diseases. 

To prevent this, what you can do is to give your plants the time to transpire before the temperature gets higher, particularly when watering them in the morning. You may also use a moisture meter to keep yourself in check. Moisture meters are cheap and effective, and they can guarantee to help in saving your plants, as well as decreasing your water bills.

Signs of inappropriate watering include the following:

  • Irregular drying.
  • Decreased shoots.
  • Limited root growth and immature plants of poor quality.

Tip: During the spring and summer days, you need to water them more frequently, especially when the plants are young and growing rapidly—and when the temperatures are much higher than normal.

Greenhouse Gardening Mistakes #6: Planting In Unhealthy Soil

Your plants need healthy, good soil for them to properly grow and cultivate. Having said that, don’t use dirt. Instead, opt for nutrient and mineral-rich soil.

Soil can sometimes vary even within a garden, so it’s important to find out which nutrients are missing, and try and replace them as much as possible. Make sure the soil is right for the plants and that it’s been well fertilised to help them grow better.

To make sure you won’t end up wasting your investment of gardening resources, and to save you from frustration, invest in a quality soil. A good quality soil will be a worthwhile investment, not only for your gardening happiness, but also for your health and well-being.

Tip: Consider doing a soil test to help you identify what exactly you can do to improve it for the benefit of the plants. Soil test kits are available at most garden centres or hardware stores.

Greenhouse Gardening Mistakes #7: Not Controlling the Humidity

As plants grow and develop, they take in water through their roots, and then transpire the water into the air around them. This makes humidity a natural part of any greenhouse water cycle.

However, the air can only hold enough water for as long as the temperature is maintained. When the weather starts to drop, that’s when the problem begins to arise. When this situation is overlooked, which most beginner gardeners tend to, your plants will experience severe damage.

To avoid a temperature spike, ventilate the greenhouse during the hot summer months. Make sure the ventilation windows are closed at night to prevent excessive cooling. On the other hand, you may consider using a low-tech heat sink, such as barrels of water, to stabilise the temperature in the winter.

Other than installing a ventilation system, make sure to check the air circulation as well. Proper movement of air within the environment can create uniformity in temperature, humidity, CO2 and oxygen.

Many vegetable and ornamental plants like wheat, rice, barley, corn, and oats are pollinated by wind. Movement of air within the greenhouse could also be the determining factor as to whether a plant is pollinated and able to complete its reproduction.