Greenhouse Accessories – What do I really need?

Greenhouse Accessories – What do I really need?

Which greenhouse accessories do you need?

Which greenhouse accessories do you really need?

Greenhouse Accessories

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.


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!