Greenhouse Guide for Beginners: Must Have Essentials for Greenhouse Gardening

Greenhouses are an amazing tool for gardeners to enhance their crops and increase garden activity. A greenhouse allows you to grow year-round, protect tender plants, and even create the perfect environment for tropical plants. However, before you get started, it's important to find the right greenhouse for your needs.

Greenhouses are an investment, and as such, there’s a level of detail and knowledge required before purchasing or DIYing your own. Here’s your essential guide to greenhouse gardening, with all the information you need to choose the best greenhouse for your needs. From flooring and ventilation to watering systems, heating, and side paneling, this guide will help you identify your requirements and make crucial decisions. With the right choices, your greenhouse will serve you well for many years to come.

 

1. Choosing the Right Greenhouse for Your Needs

Freestanding Greenhouse: A freestanding greenhouse is a permanent structure with ample space for plant growth. It’s built independently and is usually the best choice if you have the square footage and space in your yard. This option offers the most flexibility for gardening and climate control, allowing you to manage the growing environment effectively.

Small or Hobby Greenhouses: Perfect for beginners with limited space, small or hobby greenhouses are often made from clear plastic or polycarbonate panels. They can be placed in a garden corner or on a patio, providing a compact solution for gardening enthusiasts with a smaller footprint.

Traditional Glass Greenhouses: Glass greenhouses offer maximum light transmission but can be more expensive and fragile. They’re ideal for those seeking a permanent structure and have enough space for it, while also being less suited for areas with harsh winds and extreme winters.

Polycarbonate or Polyethylene Greenhouses: These materials are durable, provide excellent insulation, and are a good choice for areas with extreme temperatures. They offer better protection from the elements compared to traditional glass, making them more suitable for diverse climates.

Lean-To Greenhouse: A lean-to greenhouse is attached to a wall of your house or another structure, making it ideal for limited space. This type of greenhouse helps reduce heat loss and provides additional warmth during cold weather. While you may have less space for plant growth, lean-to greenhouses are easier to build and tend to be more affordable.

 

2. Greenhouse Frame Materials

The frame of a greenhouse provides structure and stability. It’s important to choose a material that can withstand harsh weather, strong winds, and support the weight of greenhouse covering. Different materials provide varying degrees of insulation, light transmission, and protection from the elements. 

Aluminum: Aluminum is one of the most popular materials for greenhouse frames due to its lightweight, rust-resistant, and long-lasting qualities. It’s easy to work with and can support many types of greenhouse coverings like polycarbonate panels or polyethylene film.

Steel: Steel frames are incredibly strong and durable, making them a good choice for larger or freestanding greenhouses. They can handle heavy snow or high winds but need a rust-resistant coating to prevent corrosion over time.

Wood: A wooden greenhouse frame gives a more natural aesthetic and can be very durable if treated properly. However, wood requires ongoing maintenance to avoid rot, particularly in areas with high humidity or frequent rainfall.

PVC: For smaller or DIY greenhouses, PVC pipes are a budget-friendly option. They are lightweight and easy to assemble, but they are less durable than metal frames and may not withstand extreme weather conditions.

 

3. Greenhouse Covering Materials

The covering material determines how much sunlight enters the greenhouse, the level of insulation, and how well the structure resists weather conditions.

Polycarbonate Panels

Twin-Wall Polycarbonate: This is a popular choice due to its superior insulation properties and light diffusion. It is durable and can withstand strong winds and snow. Polycarbonate is also UV-resistant, helping protect your plants from harmful sun rays.

Single-Wall Polycarbonate: A thinner version of polycarbonate, this material is slightly less insulative but still offers good durability and light transmission, making it ideal for moderate climates.

Polyethylene Film (Plastic Sheeting)

Single-Layer Polyethylene Film: This is the most common and affordable greenhouse covering material. It offers good light transmission, is flexible, and easy to apply to a variety of frame types. However, it doesn’t provide as much insulation as polycarbonate and can wear out over time, especially in regions with harsh weather conditions.

Double-Layer Polyethylene: Two layers of plastic sheeting trap air between them, offering better insulation compared to single-layer plastic. This material is often used for large walk-in greenhouses or in colder climates, where additional warmth is needed.

Solexx Greenhouses

Solexx is a type of double-walled translucent material that provides excellent insulation while still allowing plenty of natural light to filter through. It reduces heat loss during the winter months, making it an effective choice for maintaining a consistent temperature inside the greenhouse.

Shade Cloth

Shade cloth is an essential material for managing excessive heat during the warmer months. It helps reduce the amount of direct sunlight entering the greenhouse, preventing overheating and protecting more delicate plants from sunburn.

Glass

Glass offers excellent light transmission and can last a long time if properly maintained. However, it’s fragile, expensive, and can be challenging to work with. Depending on the amount of sun exposure and surrounding materials, glass can also pose fire hazards.

Fiberglass Panels

Fiberglass is a durable, lightweight material that offers a good balance of insulation and light transmission. It’s less likely to break than glass but can yellow over time, reducing light transmission. Fiberglass is a common choice for greenhouses in rural areas or places where durability is a priority.

 

4. Greenhouse Flooring Materials

Gravel: Most useful for providing excellent drainage in greenhouses, preventing water from pooling around plant roots and reducing the risk of root rot. The pros include easy water flow and low maintenance, but the cons are that it can be uncomfortable to walk on and may shift over time. 

Brick: Offers a stable, easy-to-clean surface, ideal for small to medium-sized greenhouses. The pros are durability and ease of maintenance, but the cons are the need for proper drainage underneath to avoid water buildup and eventually mold.

Pavers: Similar to brick, offer a stable surface that’s easy to sweep, but like brick, they need proper drainage to prevent water pooling. The pros are easy maintenance, while the cons include the need for good drainage. 

Concrete: A popular and permanent, solid foundation, perfect for larger, walk-in greenhouses. The pros are durability and stability, but the cons include its high cost and lack of flexibility for gardening or transporting. 

Weed Barrier Fabric: A simple solution placed beneath flooring materials to prevent weed growth and ensure a cleaner environment. The pros are effective weed control, but the cons are that it may need replacement over time and doesn’t contribute to drainage.

 

5. Choosing Light 

Natural Light: The best and most energy-efficient option, natural light should be maximized by positioning your greenhouse in an area that receives the most sunlight throughout the day. Transparent materials like glass or polycarbonate allow sunlight to filter through, helping plants grow without additional energy costs. The downside is that it may not be enough during the shorter days of winter.

Fluorescent Lights: These are an energy-efficient choice, perfect for providing supplemental light in cooler greenhouses or during the winter months. They are good for seedlings and low-light plants but may not provide enough intensity for larger, more light-demanding plants. The pros are energy savings and low heat production, while the cons are limited light intensity.

LED Grow Lights: LED lights are highly efficient, offering specific light wavelengths to encourage plant growth. They consume less energy than traditional lighting and generate less heat, which is great for temperature control. The pros include energy efficiency and customizable light spectra, but the cons are the initial cost.

High-Pressure Sodium (HPS) Lights: These lights are known for producing intense light, making them suitable for flowering or fruiting plants that need a lot of light. The pros are high light output and good for large greenhouses, but the cons are higher energy consumption and heat production, which may require ventilation adjustments.

Metal Halide (MH) Lights: These are similar to HPS lights but emit more blue light, ideal for vegetative growth. They also produce high light intensity but are less energy-efficient than LEDs. The pros are good light quality for plant growth, but the cons are high energy use and heat output.

 

6. Heating Options

Electric Heaters: These are simple to install and use electricity to generate heat. Electric heaters are ideal for small or hobby greenhouses, providing a convenient option for short-term heating during colder months. The pros include ease of use and precise temperature control, but the cons are high energy costs for larger greenhouses and reliance on electricity.

Gas Heaters (Propane or Natural Gas): Gas heaters are commonly used in larger greenhouses because they can generate more heat at a lower cost than electric heaters. These are ideal for colder climates or greenhouses that need consistent warmth during the winter months. The pros are lower operational costs compared to electric heaters, but the cons include the need for ventilation to avoid carbon dioxide buildup, gas detectors and the installation of gas lines.

Hot Water or Hydronic Heating: This system uses a boiler to heat water, which is then circulated through pipes or tubes placed throughout the greenhouse. It’s efficient for larger greenhouses and offers even heat distribution. The pros are consistent and uniform heating, and energy efficiency if using solar or other low-cost energy sources. The cons include the initial setup cost and the need for maintenance.

Wood or Pellet Stoves: These stoves burn wood or pellets to generate heat, providing a cost-effective solution in rural areas with access to these resources. The pros are lower heating costs and independence from utilities, but the cons include the need for a reliable wood supply, regular maintenance, and constant manual operation.

Radiant Floor Heating: This system involves heating cables or pipes installed beneath the floor, warming the soil directly and providing an even temperature for plants. It’s great for maintaining root zone warmth, especially for sensitive plants. The pros are even heat distribution and reduced air circulation, but the cons include higher installation costs and the need for good floor insulation.

Propane or Kerosene Space Heaters: These portable heaters are suitable for small or temporary greenhouses. They are useful for quickly warming a greenhouse during a cold snap or early spring. The pros are portability and ease of use, while the cons include higher fuel costs, short term planning and the need for proper ventilation.

 

7. Ventilation Options

Natural Ventilation: Natural ventilation is ideal for moderate climates and small to medium-sized greenhouses. It works by utilizing roof vents, side vents, or louvered openings to allow warm air to escape while fresh, cooler air enters. The stack effect, where hot air rises and exits through higher vents, naturally pulls cooler air into lower side vents. This method is energy-efficient, low-cost, and simple to operate. However, it may not provide sufficient airflow in very hot climates or large greenhouses, making it less effective in extremely hot conditions.

Mechanical Ventilation: Mechanical ventilation is best suited for larger greenhouses or areas with extreme heat and humidity. This system uses exhaust fans to pull air out of the greenhouse and intake fans to bring fresh air in. Power vents can also be electronically controlled to open and close as needed. It offers consistent and controllable airflow, making it effective for cooling large spaces. However, it comes with higher energy consumption and maintenance costs, which can be a downside for some growers.

Hybrid Ventilation: Combines natural ventilation with mechanical assistance, using fans during hot weather when natural ventilation alone isn’t enough. This system provides flexibility to handle different conditions and can be energy-efficient when used properly. The downside is that it can be complex and expensive to install, which may not be suitable for all growers.

Automated Ventilation: Automated ventilation is great for greenhouses where hands-on management is impractical. It uses thermostats, humidity sensors, and automatic openers to control vents based on temperature and moisture levels. This system offers precision, ease of use, and energy savings through automation. However, it requires a higher initial investment and may need expert intervention for repairs or maintenance.

 

8.Humidity Solutions

Dehumidifiers: They work by removing excess moisture from the air, keeping humidity at optimal levels for plant health and preventing mold or mildew. The main advantage is that dehumidifiers are effective in managing humidity in closed, high-humidity environments. However, they can increase electricity costs and may require regular maintenance to function properly.

Misting Systems: Are beneficial for tropical plants or during the hottest months when humidity can drop too low. They can be set on timers or controlled manually to maintain humidity levels in dry conditions and support the needs of moisture-loving plants. However, if overused, they can lead to waterlogging and may increase water usage.

Humidity Sensors and Controllers:  Perfect for automated humidity control in larger greenhouses. These systems use sensors to monitor humidity levels and activate dehumidifiers or misting systems when necessary. The primary advantage is that they allow precise control over humidity levels, ensuring optimal plant growth. However, the higher initial cost and ongoing maintenance for the sensors can be a downside.

Shade Cloth and Fans Combo: The shade cloth reduces direct sunlight and temperature inside the greenhouse, preventing excessive evaporation that can lead to high humidity, while fans circulate air to prevent stagnation. This system is effective in managing both temperature and humidity and improves airflow. However, it is not a standalone solution for high humidity levels and may require additional equipment.

Wet Wall and Fan System: Particularly useful in hot and dry climates or greenhouses that require continuous cooling and humidity control. It works by using a large, porous wet wall saturated with water that cools the air as it passes through, while fans draw the air through the wet wall, lowering both temperature and humidity. This system is cost-effective for cooling large greenhouses. However, it needs regular maintenance to prevent algae and buildup.

 

9. Watering systems

Drip Irrigation Systems: Are ideal for providing consistent, targeted watering to plants in greenhouses. They work by delivering water directly to the base of each plant through tubing and emitters, minimizing water waste. Drip irrigation is efficient, reducing water runoff and keeping foliage dry, which helps prevent diseases. However, it can be costly to install initially and may require maintenance to prevent clogging in the emitters.

Soaker Hoses: They deliver water along their entire length, allowing it to seep out slowly and evenly to the roots of plants. This system is easy to set up, cost effective and maintains consistent moisture levels in the soil. However, it may not be as efficient in areas with uneven plant placement or in larger greenhouses, and hoses can degrade over time, requiring replacement.

Sprinkler Systems: Work by distributing water through a series of sprinklers that mimic rainfall. Sprinklers are excellent for watering large areas quickly and can cover the entire greenhouse. However, they can waste water if not properly calibrated and may wet the foliage, increasing the risk of fungal diseases.

Automatic Watering Timers: They can be added to drip irrigation, soaker hoses, or sprinklers to automate watering schedules, ensuring plants get the right amount of water consistently. Timers save time and reduce the risk of overwatering or underwatering. However, they can be a bit expensive and require regular checking to ensure proper function.

Wicking Systems: They work by drawing water up from a reservoir into the soil through capillary action, keeping the soil consistently moist. This system is low-maintenance and water-efficient, making it ideal for small-scale gardeners. However, it’s not suitable for large greenhouses or plants with high water demands, and it can be slow to deliver water if not set up properly.

Rainwater Harvesting Systems: This eco-friendly option is perfect for areas with frequent rainfall and helps reduce water bills. Rainwater is also beneficial for plants as it’s free from chemicals found in tap water. However, it requires a good collection system, and the amount of water available can vary depending on weather conditions.

 

 

Final Thoughts

Now that you know the available options for building your greenhouse, you can make informed decisions about the must-haves and red flags to consider. Your choices will depend on what you're looking for and what you can afford in terms of space, budget, maintenance, resources, and time. With the right tools and knowledge, and a little patience, you’ll be able to create a thriving garden space. Follow these essential tips to get started, and before you know it, your greenhouse will become a central part of your gardening routine.