Some people try to buy everything they can when they purchase their greenhouse. Others think that all they need is the greenhouse itself and they are ready to go. I find flaws in both ways of thinking. A greenhouse is a building – nothing more, nothing less. The greenhouse itself with contribute virtually nothing to the controlling of the environment. It will not heat itself or cool itself without the necessary components.
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Cooling the Greenhouse
Ventilation Systems
Some people believe that they will not need a ventilation system. This may be a correct assumption under some circumstances. They feel that they will not be using the greenhouse in the summer so they will not need this. Although I have heard my ventilation system run on a bright, sunny 60 degree day in the winter. I keep my thermostat set on 90 degrees.
I recommend getting the ventilation system at the same time as the greenhouse due to the fact it is installed directly in the walls. If you have a polycarbonate greenhouse it is easy enough to retrofit this at a later date by cutting the polycarbonate. But, if you have a glass greenhouse retrofitting is more difficult.
A ventilation system will consist of an exhaust fan which should be placed up high on one end, 1 or more intake shutters which should be placed down low on the opposite end and a thermostat. These systems should be appropriately sized for your greenhouse.
Of course if you don’t have electricity or want to use passive methods they are available also. There are also solar powered ventilation systems available at this time.
Passive cooling
Passive cooling can be done several different ways. Probably one of the simplest and least expensive ways is using a shade cloth. This can be placed on the inside or the outside of your greenhouse. This is simply like standing underneath a shade tree in the summer. It will help keep the intensity of the sun and the heat down in your greenhouse.
Shade cloth – While you don’t necessarily need to purchase the shade cloth at the same time as the greenhouse keep in mind that they are usually made for you as ordered and can take 2 – 3 weeks to receive. Don’t wait until the last moment to purchase this if you feel you will need it.
Roof vents and side vents – These are part of the structure, so they should be purchased and installed when building the greenhouse. Warm air rises so the roof vents will allow it to escape. The side vents add a chimney type effect drawing the air through the greenhouse and out the roof vents.
Roll up side curtains – If you are going to use these you should purchase them at the same time as the greenhouse. They can be retrofitted, but installing them when building the greenhouse is the simplest. They simply roll up and allow added ventilation for the greenhouse.
Heating the greenhouse
If you are purchasing the greenhouse in the fall and intend to use it for the winter you should definitely purchase this at the same time you get your greenhouse. The only exception to this is for someone who is not going to heat their greenhouse at all. This all depends on the crops you are growing and their needs.
Be sure to use a heater that is meant for a greenhouse as there is lots of humidity and water spraying inside. You can get these in natural gas, propane or electric.
Greenhouse Benches
Benches can be added at anytime since they are not attached to the greenhouse itself. Be sure to use a bench that is no more than 3’ wide so you can reach all of the plants to tend to them. If you are doing a center aisle and can work the bench from both sides you can use a 4’ wide bench.
Greenhouse Circulating Fan
This is the most often overlooked and most critical accessory for a healthy greenhouse. These should run 24/7. They mix the air and keep a more consistent temperature throughout the greenhouse and can reduce overall heating costs. A circulating fan helps to reduce the humidity in the plant canopy discouraging mildew and plant diseases. Carbon dioxide utilization, a necessity for plants, is improved. Carbon dioxide is used during photosynthesis along with water to be converted to sugar (food for the plant) and oxygen.
Greenhouse Lighting
Most greenhouse will have enough lighting for hobby greenhouses. If you are growing commercially and looking for expanded production, you may add these when building the greenhouse.
You may need these if you could not place your greenhouse in an area with enough natural lighting. I used HID lighting (but recommend LED lighting now) in my greenhouse for supplemental lighting for my tomatoes in the winter. The daylight hours are just too short.
While lighting can be added at anytime if you know you will need them go ahead and purchase them at the same time you get your greenhouse. If not wait and watch your plants. They will let you know if they need extra light.
Misting or Watering Systems
I think this is something best left until you have the greenhouse together and see how the framing is. That will help you determine the layout of your watering system. We have always used a frost proof hydrant in our greenhouse so we don’t have any worries about freezing. The automatic system I prefer is an overhead misting system. This consists of tubing hanging from the greenhouse frame with emitters at specified placements. I then put this on a timer. But, another watering system may better fit your needs. Just be sure to keep all watering away from your heaters when setting up the system.
Max/Min thermometer
I think these are an important tool to have in your greenhouse. They let you know just what is going on. These thermometers register the highest temperature during the day and the lowest temperature during the night. That way you can really regulate the temperature where you want it. They are a small investment and I would recommend getting one when purchasing a greenhouse.
Conclusion
A greenhouse needs accessories to function properly and to maintain the proper climate for your growing needs. It has always been my belief that greenhouse growing is a learning curve for all of us. We all have a little bit different climate. We are all growing different crops or ornamentals with different needs. Don’t buy a greenhouse and load up on all the accessories available at once. Get the necessities and use your greenhouse for a while. Your plants will soon let you know if there is anything that they need. Don’t be overwhelmed by all of this. The worst that will happen is you may have to replace a plant or two. And don’t be fooled, this happens to all of us, even 40 plus year growers! Enjoy!
Are you building a homemade polyfim greenhouse, but are unsure about how to ventilate it? Here are a couple of solutions for you. You can see that this greenhouse has roll up sides, an option which is readily available, but can be costly. We have 2 options available that insert directly into your polyfilm covering without any additional framing. They use the channel base and wiggle wire to insert directly into the greenhouse covering. You simply cut the film and install these accessories directly into the film covering without any additional framing.
Intake Shutter with Solar Powered Opener
The first option is a solar powered greenhouse shutter. This has louvers and a wax cylinder powered opener. It will open when it is warm and close when it is cool automatically. They are available in 6 different sizes. If you would like to use this on another type of greenhouse such as polycarbonate, we can remove the base channel and you can insert this directly into a wood framed opening.
Solar Powered Roof Vent
The second way to do this is with a solar powered roof vent. This is a lightweight polycarbonate vent. It weighs less than 10 pounds, but you get all of the benefits of the durable polycarbonate covering. It also has the was cylinder powered opener that will automatically open and shut the vent as the temperature requires. To install this you simply cut the polyfilm and install it directly into the greenhouse covering.
A lot of people prefer to build their own greenhouses rather than purchase a kit. With these 2 ventilation options, there is no reason not to build your own polyfilm greenhouse.
Getting ready to heat your greenhouse? Well, now is the time to either check your existing heater or to purchase a new one. Our top pick, the Southern Burner natural gas or propane greenhouse heater is going to have a price increase (the first time since 2008) on November 20th. So you want to be sure to order prior to that date. This is a super greenhouse heater that will fit under a bench and not take up any valuable floor space. It requires no electricity. The heater is all aluminum and stainless steel. They will keep the temperature at the top of the greenhouse within about 5 to 7 degrees of the floor heat. There is a vented and a non vented model available. The vented model is 25,000 BTu’s and will be adequate to heat most small hobby greenhouses. If you have a larger greenhouse you would simply add a heater or two. There is a formula to calculate how many BTu’s will be required to heat your greenhouse based on the size of your hothouse, the glazing type, the indoor and outdoor temperatures. Please be sure to follow this formula, or your heater may be too small to get your greenhouse to the desired indoor temperature. Plan ahead. Winter is headed our way. Don’t be left out in the cold this year!
If you are in the process of designing or purchasing a greenhouse you probably have questions about what accessories you should purchase with the greenhouse. I get asked this a lot. Some people want to completely ignore the accessories, while others have read every article and believe they should buy everything that you can put in a greenhouse. My recommendation is to start with the ventilation package. Yes, you will need it even if you are only overwintering plants and even if you are in a cold location. I have seen sunny winter days when it was 60 degrees outside and my fan and shutters were operating. And, I keep my ventilation system set at 90 degrees. On the other hand, I hate to see people load up on a lot of items that they will never use. A heater is a good idea, if it is close to the time of year you will need it, or if any modifications to the structure are needed to accommodate for vents, etc. I think the rest of the items should be added as needed.
Here is a nice article from our friends at Garden and Greenhouse which talks about some small hand tools and re purposed items. These are things probably most of us would never think about, but will be used over and over again.
If you already have or are thinking about getting a greenhouse you should consider purchasing several inexpensive tools and related products. Although the items are not very expensive they can make a difference in how much you enjoy greenhouse gardening and how efficient you are at doing it.
This is an excellent article from our friends at Garden and Greenhouse magazine regarding the need for consistency in your greenhouse environment. In order to have the best, consistent growth it is important to have the best, consistent climate. Although I must say that I find this a little bit more on the advanced end of greenhouse growing. I do not suggest that someone jump in with every known greenhouse accessory when initially purchasing their greenhouse. I recommend getting a ventilation system, as it is an integral part of the building. You can retrofit them, but it is easier to install them when you are putting up your structure. A heater is also a good accessory to order with your greenhouse. As far as some of the other systems are involved, I suggest experimenting and finding out what you need rather than outlaying a bunch of money for accessories that your climate or plants may not need. Unless you are an experienced orchid grower, for example, you will know what humidity, etc your plants will need. Then it would be a wise decision to get your greenhouse set up with these systems at the beginning.
Consistency is the key to unlocking the maximum potential of an indoor garden or greenhouse. Plants thrive on consistency. Plants respond best to light energy, atmospheric conditions, and nutrients when they are kept as consistent as possible. Like people, plants burn sugars to provide energy for growth. In contrast to people, plants have the unique ability to create those sugars from sunlight. The creation and consumption of these sugars are actually part of a chemical equation. In other words, there are countless chemical reactions occurring at all times within and around the plant that contribute to healthy development.
When atmospheric conditions, lighting and nutrient levels are at optimal levels, the plant has everything it needs to make those chemical reactions happen without interruption. When the chemical reactions can occur without interruption, the plant’s growth rate is maximized. Maximizing the potential of a particular crop is the goal of just about every indoor horticulturist or greenhouse hobbyist. In order to maximize the potential of an indoor garden or hobby greenhouse, a horticulturist should closely monitor the consistency of the garden’s temperature, humidity, lighting and nutrient solution. Each of these factors has a significant effect on the chemical reactions that contribute to plant growth.
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