DIY Greenhouse Guide

Looking to create a small greenhouse, a lean-to greenhouse, or a mini greenhouse to grow fruits, vegetables, herbs, or flowers for your family to enjoy?  This DIY greenhouse guide is a great place to start.  We will review types of greenhouses, materials you could use, what to plant and when, and how to maintain your greenhouse.
 

When building a greenhouse there are a variety of covering materials to choose from. Selecting the best material is dependent on your regional and personal needs.

Polycarbonate is considered one of the best covering options for greenhouses. Corrugated polycarbonate like Tuftex PolyCarb™ is a typical DIY grade plastic when it comes to your hobby greenhouse. When maintained properly it can easily last longer than 10 years. The polycarbonate panels help diffuse light and retain heat and humidity, making year-round gardening a breeze.

Twin-wall or doubtle-wall polycarbonate is a type of multiwall polycarbonate that is flat and has an extra layer of polycarbonate material. It is more robust, making it ideal for areas with harsher weather conditions like hail and long or colder winters. The additional layer of material creates chambers that insulate better for heat. Installing multiwall is slightly more difficult than corrugated polycarbonate.

Utility grade polyethylene roles may last only 1-2 years, but in warmer climates they may be an option to consider if you are not able to properly ventilate a corrugated polycarbonate greenhouse. Polyethylene is typically used on hoop houses (see “what type of greenhouse structure is best for me”) and primarily diffuse light. This type of sheeting offers little to no protection from weather or nature and may need to be repaired and maintained more frequently.

Many other material types like acrylic, glass, and woven covers are typically not for greenhouse applications, overly expensive, and/or designed for more commercial grade applications. Fiber-reinforced-plastic, also known as fiberglass or FRP was an industry norm for years prior to the emergence of polycarbonate. Though fiberglass is still available and thus a viable option for your home greenhouse project.

Depending on your region or climate you may have additional considerations to evaluate. In warmer or colder regions, temperature and humidity control may be more important than in more mild or temperate climates. Not only do you need to consider the material used in the greenhouse, but also its structure when making these decisions.
Limitations to your available land, such as in a city might also impact your decision. Perhaps consider a lean-to in this instance. The amount or variety of plants can impact your building design type. Hoop houses and gable-style greenhouses offer you the most space. If you plan on building more on to your greenhouse in the future, you may also want to consider a scalable gable-style greenhouse. Below you will find a variety of greenhouse structure options and their pro’s and con’s to review as you make your consideration.

A lean-to style greenhouse is an easy to build structure that typically will (but does not have to) utilize the wall of an existing structure to provide one side of the enclosure. It is important that when choosing this design, the structure is attached on the side of the building with the most sun. The benefits of this structure type include needing fewer building materials if attached to the original structure, occupying less space, and typically near necessary amenities like water and electricity. These structures are great for small lots and limited space.
The cons of this structure include the limited space, which has several other implications as well. The one-sided design means a limited amount of light enters the structure, from only one side. The lower light exposure will minimize plant growth and plants will grow in one direction. Temperature control might be impacted by the adjacent building as well.

This style of greenhouse is probably what you think of when you are thinking of a greenhouse. You might be thinking of a larger professional greenhouse which features several of these connected, called a ridge & furrow greenhouse. But one simple gable is perhaps the best for a serious hobby greenhouse. A gable style greenhouse leaves the most room for plants, in appealing to look at, drains snow and rain off the roof, promotes high light diffusion, and its uniform shape maintains uniformity in temperature. Designs are also easy to scale or replicate by simply increasing the length.
When setting up a gable structure it is important to know that with the robustness, there is some additional material cost. Some of your vertical beams will need to be stronger (compared to the lean-to) to support this free-standing structure.

An A-frame greenhouse is similar to a gable style greenhouse, but the sloping roof terminate at or near the ground. This helps to minimize cost, but the trade off is space for both your plants and for you to navigate within the structure.

Hoop houses are the most common greenhouse for people who are in very warm climates and plan on using polyethylene sheeting. Hoop houses typically utilize lightweight piping to create hoops around the growing area. Sheeting is then draped over the hoops, occasionally with a void near the ground to help with ventilation.
The sheeting used on hoop houses diffuses light well and tends not to retain as much heat as polycarbonate and other panel products. In warmer climates this can be an advantage since panel greenhouses would require you to build in ventilation. Hoop houses are also less expensive when do the initial build. But for these up-front savings, expect to make repairs regularly and be ready to take more precautions against animals.

When you think of the gothic style, you probably think of two sides of a building, slowly sloping to the middle, then turning up to a point. This ornamental shaping is like a gable style roof, but without the two distinct sides. The benefits of this structure are also similar. But if you can find materials or shape this ornamental design yourself you have a pretty and functional backyard greenhouse.
Polycarbonate panels can be bent to conform to these designs without any special tools. It is always important to predrill holes in your polycarbonate, but especially when bending it into a curved shape. Line up each screw hole and drill these holes prior to installation. Always check the manufacturer’s guidelines before bending polycarbonate to ensure your curve is within the material tolerances.

Greenhouses offer you the ability to plant nearly anything you want at various points in the year. The only limitations are your greenhouse itself since you can always supplement light, heat, humidity, and other important growing conditions. For your first greenhouse consider some of these plants which are easy to start with.

Leafy greens light arugula, cabbage, and other lettuces

Larger herbs or herbs you use very frequently

Root vegetables like onions, potatoes, beets, and garlic

Easy plants like peppers, strawberries, tomatoes, and sunflowers

Gardening in your greenhouse is not without special considerations versus your normal outdoor growing. When building, maintaining, and gardening in your greenhouse it is important to consider these following common mistakes.

Clean your greenhouse by removing interior and exterior debris to ensure light reaches your plants unobstructed.

Plants or debris leaning against or attaching to the interior of your greenhouse can create a small micro-environment which heats up and increases humidity. In these small areas, mold could form, so it is important to have space between plants and your greenhouse walls.

Always review the guidelines for whatever material you use for your greenhouse before cleaning. Use natural, plant safe cleaning solutions; rinse thoroughly; and make sure the solution does not have an adverse reactions in heat or sun.

Make sure you control the temperature of your greenhouse. Ventilation windows are the easiest way to manage this in most climates. But fans or heating could be needed in certain areas depending on what you plant.

Nearby trees could impact your greenhouse by limiting light through shade or falling debris and leaves. Roots can also invade your greenhouse and falling limbs can damage even stronger greenhouse panels.

Light diffusion is important to promote healthy even growth in your greenhouse, but shade is also needed. Plants need time to “rest” to prevent them from being overheated. Shade cloth is one such option to help reduce heat and if you need to manage part of your greenhouse for lower-light plants.

Ventilation and humidity control is essential to a successful greenhouse. Mold and fungus can grow when humidity is above 85%. Optimal greenhouse humidity is typically 80%. So, the line between optimal and hazardous is small. Ventilation help manage both temperature and humidity.

Soil management is also key if you plant in the ground within your greenhouse. The land under your greenhouse is not a closed system, it still interacts with the land around your greenhouse. Because of this, you may need to consider the surrounding areas around your greenhouse in addition to the soil within. You may also want to plant in beds, boxes, or using a non-soil method within your greenhouse to manage your plants’ nutrients more effectively.

All sheeting and panels that protect your greenhouse also alter the light. Early in their life polycarbonate panels help diffuse light and let in the optimal wavelengths of light. Over time all panels will slowly degrade, so it is important to manage your structure

Onduline has a dedicated team of customer service professionals here to help you with planning your chicken coop material needs. Our Ondura Premium Series offers a strong and quiet roofing to keep your hens calm and happy. Our Tuftex SeaCoaster create great cladding for the interior that is easy to clean, survives in caustic environments, and will not rot, rust, mold, or mildew. Our Tuftex PolyCarb™ panels and ridges offer great solutions for adding natural light.