Geodesic Greenhouse FAQ
Some commonly asked questions about building a greenhouse dome, food security and other geodesic things.
Why a geodesic dome and not a frame type greenhouse?
I suggest a geo dome for several reasons:
Number 1: The dome shape is is the most efficient use of space and (to some more importantly) its very beautiful. Because a geodesic greenhouse dome gives the absolute maximum volume of space while using the very least amount of materials it is amazingly energy efficient AND cost effective space.
Number 2. Domes handle snow and wind loads better than any other shape of building. They are incredibly strong, self supporting and withstand earthquakes too! Think about radar domes down in the snow and ice of antarctica for a dome in a harsh climate.
Number 3. Domes of all sorts, but especially ones designed for growing have a very even heat cycle throughout the day and night. Nice slow changes of temperature and no odd corners for chills and drafts to develop, it all adds up to happy plants.
Can I really grow food in my geodesic dome greenhouse all year long?
Absolutely 100% Yes! Dome greenhouses have two main seasons: warm and cool. During the warm summer months you will be growing: cucumbers, pepper, tomatoes, zucchini, squash, etc.
Then during the cooler winter months you plant and harvest hardier, cool weather crops like: leeks, lettuce, peas, spinach, kale, swiss chard, brassicas (cabbage, cauliflower, brussel sprouts) and herbs. If the temperature does go down near freezing, you may notice that growth slows and but as soon as it warms up with solar or other heat, growth picks right back up. These unique features are specific to greenhouse domes and allow you garden any time you like and produce fresh vegetables, fruits, and flowers every day of of the year!
Why should your greenhouse dome kit have a water tank in the back?
The water/fish tank is the heart of the dome. In cooler weather it soaks up the heat of the sun during the day and then releases it at night. Then when the weather is hotter in the summer the water tank acts as cooling, helping your dome to not overheat. You can use your tank as a water garden growing aquatic plants, or for growing fish (which makes a great source or organic fertilizer too).
How much food can I grow in a year in my Dome?
Everyone will be different, but in my experience most people end up with more food than they can eat at home and end up trading, giving or selling some. If you have a reasonable grasp of basic gardening and decent soil fertility, the figure that most people use is 2.5 pounds of finished food per square foot per year (this can be increased exponentially by using growing tubes and multi tier beds).
Based on the minimum calculation, a 350 sf (22ft diameter) dome will produce over 800 pounds of food per year. Considering the average north American consumes about 200 pounds of vegetables per year you can size appropriately.
Will my geodesic greenhouse dome ever freeze?
Maybe, possibly, potentially, it depends, probably not. Your dome might possibly go below freezing during extended, severe cold weather with low sun exposure. However by adding a small chicken coop with 6 hens you will probably never go below freezing (gives a whole new meaning to the idea of a “hot chick”!).
In the worst case scenario where you have had a few hours at or below freezing, plants will continue to grow, especially if you are planting with the seasons. Read the chapter in Kacper’s book on the amazing space age insulating, transparent material that scatters sun so plant don’t get “leggy” while keeping your dome toasty warm.
Is all this greenhouse dome stuff going to be a lot of work?
Most people find growing and harvesting their own food to not be work at all. More like Zen meditation with amazing food at the end. However if you are only doing it for the end result, then you might find that your main “work” is harvesting all of your wonderful produce, deciding what amazing meals to create and finding enough people to share it with!
Generally most greenhouse gardeners find that they invest around 4 hours per week in their dome. And as many happy “domer” will tell you, it’s not a chore! Because the geodesic greenhouse is such a rejuvenating, peaceful and relaxing place to be they actually save money, on therapy! The main “problem” most people find is staying away from it!
Remember the automatic non-motorized vents mean you never have to worry about overheating, while the solar water tank / fish pond means you never have to worry about turning on the heat if you are away for a day or so.
Do I need a building permit?
In many jurisdictions a growing dome is regarded as a temporary structure, as it does not have a foundation and can be easily disassembled. That is another advantage, if you do ever need to move you can take your dome with you! Be sure to double check with your local departments, officials, homeowners associations, etc. because its best to find out about permitting before you build a gaint dome.
Does my greenhouse dome need a concrete foundation?
No, because your dome is so light and self supporting it can sit on a gravel foundation. You will need to anchor it to the ground, which can be done in a number of easy and inexpensive ways.
What about pests and diseases in my garden?
Every greenhouse is different. And generally because the plants are getting ideal growing conditions they are in the best shape to fight off disease and pests. However because its a good place for plants it can also become a nice home for insects as well.
Use beneficial predatory insects and organic methods of biological pest control and good care and feeding of your dome garden and you should have no major problems. In the end keeping on top of things is the best weapon!
Happy greenhouse growing!
I want to cover my geodesic greenhouse with some poly-bubble wrap.( not what people call “poly keder”, but the very simple one with large bubbles what you can buy anywhere).
Do You think it will keep the temperature enough in the greenhouse???
thanks for your answer
The poly kedar is a great choice! Of course, matched with a fish tank passive heat storage system to hold heat over night and provide nutrient rich water for your plants! See my post on aquaponics for more info on that.
Hello, this is amazeing! I was looking into the walipini but came across this. I am considering changing my plans. Can you please explain to me what a fish tank passive heat storage system is? Thank you
Thanks for the question. The Walipini looks great too as long as you don’t have high water table issues!
Using tanks to moderate the interior temperature of the dome is fine as long as you have a heat source, so in my case it would be evacuated solar tubes or the rocket mass heater. Either way hot water would be pumped through the fish tanks to keep the fish alive and heat the dome. Depending on your climate the biggest thing to think about is north side insulation and your dome covering.
On the EasyDome that I built I went with shrink wrap on the outside and greenhouse plastic on the inside to create a “dead” air space. However using polycarbonate or poly kedar would make the dome even warmer in winter.
If you have sun every few days then the evacuated solar tube type solar water heater is a great way to go. The good ones even make hot water when the sun is behind some cloud. Once the water is hot then pump it through water tanks, grow beds or the floor of the greenhouse.
Remember plants like it to be cool on top and warm on the roots (usually) so heating the grow beds is anther great way to keep food production up all winter. Or you could do what my father does and and build the greenhouse onto the side of the house, crank up the furnace and heat the house and greenhouse!
We live in South Central Alaska on a wooded mountain side about 50 miles NE of Anchorage. Our winters dip down below zero degrees fahrenheit, but average about above 5 to 10 above zero for several months, Our goal is to be able to grow vegetables year round. Our growing season outdoors is about 95 days.
My questions have more to do with the skin or covering for a bio-dome greenhouse. Ice build up is a potential problem. Would you recommend skrink wrap in our case, or something different? We plan to keep the dome heated using a rocket mass stove and water as a bio heat source.
Thanks ahead of time for your advise.
Covering a dome in those kind of temps is going to be key. Triple glazing is your friend! Look at SolaWrap as a start for the outside then sealing the inside using UV stable greenhouse plastic. Use 2×6’s to increase air gap and build a batch loading rocket mass heater suitable for Alaskan temps. This stove is outlined in Leslie Jackson Yanto Evans latest RMH book.
If you are going for chicken bio heat remember to get the poo out cause ammonia kills plants don’t know about compost heat but should be OK and you get lots of bio-available plant food at the end!
Let me know how it works out!