Would you like to prefer garden plants in the winter months by building a cold frame yourself? This guide will help you realize such an inexpensive DIY garden project yourself!
A simple structure made from reused building materials can be used to protect plants in the garden from the cold to extend the growing season. This allows for a cost-effective alternative to greenhouses that prevents damage from the elements and can act as an extension of a traditional raised bed. In addition, the transparent lid allows sufficient sunlight to penetrate, while the frame prevents heat loss and keeps the interior well ventilated. Instead of a greenhouse, you can use it to create small-scale gardening, even in the off-season. Below you will find some advice and simple step-by-step instructions.
What should you consider before you build a cold frame yourself?
Originally, this type of construction was intended as an extension of greenhouses in northern countries. They were used to harden seedlings before growing them in the garden, or to start sensitive seedlings earlier, regardless of the climate. Because thatPreferring some plant specieshas numerous advantages before the spring season, cold frames nowadays represent a practical and functional solution. However, before you start, it is important to consider the following factors and useful information:
- Such systems can be created from various building materials such as wooden boards, pallets, bricks, acrylic panels, French doors, plexiglass, foil, etc.
- You can build a cold frame yourself by placing it directly on the ground or using it to extend a raised bed.
- You can design the frame or building structure with or without a floor.
- If rodents are rooting around in your garden soil, it is advisable to place a protective net underneath when planting root crops.
- Such a frame structure can be created without strictly defined dimensions, but it should be provided with a transparent cover. However, when using prefabricated window frames made of wood or aluminum, their dimensions must be taken into account during construction.
- Depending on how tall the plants grow, the structure should have the appropriate height. Usually 50 to 90 cm is enough for this.
- To help the cold frames capture sunlight and drain water better, they should be sloped at the top. The hinged lids allow for both easier access when gardening and control of air circulation.
- As far as the roof construction is concerned, hollow chamber panels, acrylic panels or those made of polycarbonate, old glass or reinforced polyethylene are suitable.
- It is recommended to choose weather-resistant materials, such as pressure-treated wood. However, you can also treat wooden surfaces yourself with a non-toxic wood preservative such as linseed oil to seal them.
- So that the plants in it remain healthy and can thrive without any problems, the soil should also be permeable, moist and nutrient-rich.
What materials and tools to choose for construction?
Since cold frames are typically box frames with clear skylights, they are usually made of wood materials, concrete blocks, or bricks. So for a DIY project like this, you can create something practical by upcycling to give yourself a head start on gardening. However, try to choose hardwood so that your structure will be more stable. Otherwise, the construction is usually not complicated and you don't have to be a craftsman to be able to build a cold frame yourself. Here are some example building materials and tools you might consider for this purpose:
- To make construction easier, you can use old glass doors or wooden windows as hinged lids. However, if you don't have one, you can simply attach a polycarbonate sheet or even film to a wooden frame and fasten it with hinges to open it.
- If you choose wood, you can use slightly thicker wooden slats and boards to create the frame structure.
- By attaching a short and a longer bar to the top back, the lid can be held slightly or completely open.
- As for tools, you can use screws, drill/driver, tape measure, sealant, hinges and maybe a saw.
- For the lid, you can reuse or purchase a set of transparent plates or glass depending on availability and preference. These can be easily adjusted to the wooden frame of the lid using a utility knife and secured with nails.
Once you have collected everything, you can start building. Below you will find exemplary instructions for such a structure made from old windows and wooden boards. This is also suitable as an extension of a raised bed, although the design and materials used can vary depending on the situation.
How to build your own cold frame using windows and wood?
First and foremost, it is important to choose a suitable and, above all, sunny outdoor location for the cold frame. However, if you already have a raised bed and simply want to optimize it, this step is of course unnecessary. Determine the size of your cold frame based on the size of your windows or plastic panels. The typical dimensions are around 9o cm x 120 to 180 cm, although you can also have the wooden boards made by a carpenter if necessary. Otherwise, you can proceed as follows when building such a garden structure:
Assemble the frame of the cold frame
- Start with the front of the frame first by placing two front wooden slats on the floor. You can construct the rectangular frame from scrap wood or pallets, although it should be open at the bottom and equipped with a sloping lid.
- Then connect the two ends with a wooden plank by screwing or nailing it to each end of the batten. It is best to drill guide holes in front of it to make it easier to get the screws into position.
- You can then simply repeat the steps above for the remaining sides of the frame.
- First you can attach the planks to the wooden slats. To do this, place the front vertically and attach one of the side boards to the front slat.
- Repeat this step for the other side of the frame with all remaining wooden slats to complete the outer frame.
- Then move on to side boards on the two sides of the frame by drilling pilot holes for them and screwing them in.
Attach the hinged lids and add supports
- Next, you can attach the windows or the transparent polycarbonate panels as lids. It is advisable to equip it with a lid handle or lock so that you can open or close the box frame more easily.
- When attaching the cover(s), ensure that they are flush with the frame structure to prevent heat loss.
- Then attach hinges to the desired locations and screw them tightly to the lid and frame.
- Although the next step is optional, the structure will be much more functional if you also install supports for the lid. This helps you regulate the temperature inside to create optimal conditions for your plants.
- First, try screwing one end of a long wooden slat into the side, a short distance from the corner. The support batten should run parallel to the side of the frame.
- You can also use leftover pieces of wood to create a small wedge to support the wooden slat when not in use. Simply screw it tight and let the support slat rest on it.
- Then also attach a shorter support slat to the front following the same steps on the other side of the frame. Both support slats should be able to pivot easily to allow different degrees of opening depending on the ventilation required. For this purpose, you should not overtighten the screws and allow the support arms to move loosely.
- Finally, another optional but recommended step is to treat the wood surfaces with sealant. If you use plexiglass as a lid when building your own cold frame, it is advisable to seal it before attaching it.
- You can also extend the life of your plant by preventing direct contact with the ground. This can be achieved with a few bricks or wooden panels under the cold frame.
Tips for using the cold frame outdoors
- When using your DIY box in the garden, you should above all ensure optimal ventilation of the interior. This is crucial for healthy plant growth, especially in hot or extreme cold conditions. Therefore, use the support slats to regulate the air circulation and regularly check the condition of your plants.
- Also note that your plants in the cold frame can dry out despite rainfall if you don't water them enough.
- Keep the indoor temperature above freezing in winter or cold weather by either positioning the structure against a house wall or by choosing materials with good heat capacity such as bricks, stones or clay. Alternatively, you can fill black containers with water on sunny days and leave them in at night when it is cold.
- As far as pests go, slugs can easily sneak into cold frames and cause damage to your plants. Therefore, check the interior regularly for unwanted visitors and keep the lid closed when possible.
Hopefully, this guide has given you a rough idea of such a structure. There are of course numerous other designs that you can choose depending on your available space or taste. For example, there is the easy option of creating a mobile wooden frame with a triangular roof structure. This means you can only use a protective film to overwinter plants if necessary or prepare them for cultivation in the garden. Simply choose the best possible option for your situation and try to reuse existing building materials in a sustainable and environmentally conscious manner.
Also read: “MINI GREENHOUSE DIY: IDEAS FOR COMPACT & DECORATIVE GREENHOUSES FOR INDOOR OR FOR THE GARDEN“
