Depending on where you live, taking advantage of either a cold frame or a greenhouse may be in your best interest. Even in warm climates, there are advantages to both structures. However, other than heating, many are not sure what the differences are between the two structures.
- With the use of a greenhouse, you have full and complete control over the environment within the closed structure. With a greenhouse, it is about more than regulating temperature. You also have control over such aspects as humidity, lighting, and even watering.
- With a cold frame, the goal is one of protection. When the worst of cold weather hits, such as in times of frost or damaging winds, your plants are afforded a certain amount of protection. Some individuals also choose to heat their cold frames, especially in those areas that experience a lot of cold weather.
Now that we know a little more involving the difference between the two, the question is which one is the right choice for your needs?
As with most any endeavor, some pros and cons must be taken into consideration. The same goes for cold frames vs. greenhouses.
- Cold frames
Protect plants during the worst of the cold weather.
It does not offer control of climate, other than when using a heat source is.
Usually, smaller structures built simply and only a few feet in height.
Offers the convenience of year round gardening in any weather climate.
It provides the ability to control the climate, including temperature control, humidity, and lighting.
Large roomy structures with plenty of height to walk into and work in.
One of the many misconceptions most gardeners seem to suffer from is that of what the actual term greenhouse means. When most of us think of a greenhouse, in actuality, we are envisioning more of a cold frame. This is because many when they think of a cold frame, they think it is like a smaller, mini version of a greenhouse.
In a nutshell, the primary key to what differentiates a greenhouse over a cold frame is the ability to have control over the climate inside. Greenhouses are either kept at hot or cool temperatures, and this is according to the temperature during the nighttime.
If a greenhouse is kept cool, this usually means that the overall nighttime temperature is maintained above 45 degrees Fahrenheit. If the greenhouse is kept hot, then the nighttime temperature is maintained above 55 degrees Fahrenheit.
The reason for the different temperatures has to do with the greenhouse’s root temperature or soil temperature required by the plants. This temperature is vitally important for both seed germination and for the plants to be able to thrive and grow.
On the other side is the temperatures during the daytime. The solar energy that a greenhouse captures throughout the day can play a significant role. A greenhouse that is of good quality will allow a gardener to not only control the inside nighttime temperatures but the daytime temperatures as well.
There are also the areas of humidity and lighting being controlled in a greenhouse setting. A variety of plants need the benefit of moist air, dry air, or something somewhere in between. A greenhouse, as a rule, has a control system in place that will allow it to regulate the addition or removal of moisture from the structure’s air.
No matter how you look at it, plants need light to thrive and grow. There is also the fact that no matter where you live, you will have a portion of the season that optimal for growing. You can still have plants growing in the winter, however, due to the drop in the number of hours of daytime light, they will grow slower than during the prime months.
A cold frame, in layman’s terms, is simply a greenhouse, but without the ability to control the climate. Cold frames range on a smaller scale than greenhouses and can be seen as just a few square feet in size, and in some cases, up to an acre long.
The primary purpose of a cold frame is to protect any plants from the worst that winter can throw at them—including wind, rain, and cold spells that can get down to freezing. Make no mistake, even with the use of a cold frame you will still need to make sure that the plants used are adapted to the region in which they are planted.
You can choose to build your cold frame over a portion of your garden that is already planted, or you may use it to aid in seed germination that will allow you to grow a new crop in the later colder months of the year.
It is important to remember that although cold frames will help with the soil temperature, they typically only raise it no more than 10 degrees Fahrenheit. When you get into those colder months where you usually see lows in the 30s and 20s, or even as low as 10 degrees Fahrenheit, these are the type of temperatures that are best suited for using a cold frame.
There is, if the temperature warrants it, the choice of adding a small portable heater to your cold frame. When this choice is made, you would essentially find yourself walking the boundaries between a cold frame and that of the definition of a greenhouse.
When the weather is miserable cold out, there is a little trick to help your cold frame better protect your plants—that of adding an extra layer of plastic, making sure to leave a 3-6 inch space between the inner and outer layers. This creates a buffering air pocket that will trap warm air and will work to warm the area that much more efficiently.
First you will need to decide which type of plants you want to grow, and the best conditions in which they will thrive. Then, you can decide on either a cold frame or a greenhouse, depending on whether or not the climate needs to controlled during nighttime and daytime hours.