Ideal Greenhouse or DIY Hoop House Orientation and Location
What Direction Should I face my DIY hoop house or greenhouse?
Here at Bootstrap Farmer we often find ourselves explaining the different factors that can affect cost and placement when it comes to site preparation for a greenhouse and greenhouse direction. Locations of existing structures, soil conditions, wind, sun exposure, site grading and access to utilities will all play a part in deciding where you can securely place the foundation for your structure. These things will also have an effect on the overall cost of your traditional greenhouse, DIY hoop house or caterpillar tunnel build. These are all things to consider when selecting a site or assessing your back yard for the hoop house structure.
What is the best hoop house orientation?
It is ideal to build your greenhouse or hoop house in a location that gets plenty of sun year round and will not be prone to high wind pressure or flooding. This will ensure a better hoop house build and a better chance of being able to use the structure year round, even in cold weather. It is best to select a site that is flat with stable soil. You don't want the soil shifting after your greenhouse is built. We recommend grading the soil with a slight pitch to drain excess water away from the greenhouse (about 6" drop for each 100').
Top 10 Things You Should Consider About Greenhouse Orientation
- How close will the hoop house or high tunnel greenhouse be to other structures on your property?
- Do you have large trees that will shade the area or grow to shade the area?
- Is snow drift a possible problem at your site?
- Are there water drainage issues near the foundation that could be exasperated by hoop house or high tunnel runoff?
- How close to the road are you allowed to build?
- Are there easements on your property that must be taken into account?
- Will utilities (water/electricity) be available at your hoop house site or will they need to be added in?
- Is there a significant slope to the ground?
- What are the underlying soil conditions?
- What direction should a greenhouse or hoop house face? Hoop house orientation can be north to south or east to west.
DO GREENHOUSES NEED TO BE IN FULL SUN?
When deciding your traditional greenhouse or high tunnel orientation, you will want to make sure it is an area that receives plenty of light. The ideal location would be south or southeast of any existing structures. If that is not an option, the next best location would be east of existing structures to capture the most winter light. It is best to avoid building around trees that will block out too much sunlight. Trees and high prevailing winds can be a source of weather damage if trees are planted too closely to the hoop house or greenhouse.
WHAT IS THE BEST ORIENTATION FOR A GREENHOUSE Or High tunnel?
When selecting the best greenhouse orientation, always default to what is best for drainage while avoiding shading from other structures.
If you are in a northern climate (hardiness zone 6 and lower) and want to grow in the cold winter months, plan on orienting your greenhouse East to West to maximize sunlight in the winter months. Otherwise, hoop houses or high tunnel orientation should run North to South to get good light and the best ventilation.
Be sure to create a greenhouse plan before you start building. You want to make sure your plants get maximum sunlight and the structure of your greenhouse or high tunnel is on a solid foundation.
How to Plan for Site Grading Before you Build
The ideal grade for the foundation when building a hoop house style greenhouse is less than 5 degrees of slope over the length of a 100 feet. If your slope is greater than this you will need to factor in the time, labor and possible equipment costs to bring the slope within spec. If you can, move some of your soil from the high side to backfill the low side of your location. You may need to build a small retaining wall to keep the ground’s foundation in place.
The closer your foundation is to level, before you build the hoop house or greenhouse, the better your results will be. Having the ground level will improve conditions for watering purposes, drainage, and your own comfort in the hoop house when working. If you will need to bring in equipment to help with this process, consider how you will be dealing with necessary drainage channels and utility trenches. If all of these will need doing it is best to plan it out to be done all at once to avoid additional costs, labor and time later on. Watch this video Do This First! Groundwork Leveling for a Gothic Tunnel Greenhouse, for an in-depth look into this process.
Before You Dig, Check for Utility Lines
You must call utility companies to have them mark their existing lines before you dig. Conveniently this can be done by calling 811 from anywhere in the US. You can also use the website https://call811.com/Before-You-Dig to schedule utility companies to come out and mark their lines. This is necessary so you don’t hit a gas line or fiber optic cable when you start your dirt work. Typically it only takes them a few days to come out and mark any lines that you need to avoid when grading, trenching, laying foundation, or sinking ground posts.
What Utilities Will You Need Access to for Your Hoop House?
Water is the most important utility to have access to. If your closest spigot is 300 feet from your build site, how do you plan to water your plants? Will you be dragging a hose all that way every time you need to water or will you install PVC pipe?
If you will need to move the water supply to your build site, take into consideration the cost of the PVC or PVC pipe needed as well as the time and labor required to dig the trench. If you do not have experience with plumbing or PVC pipe, also consider the cost of hiring a plumber to make sure the work is done correctly the first time before your high tunnel or greenhouse foundation goes in.
Electrical Installation for Greenhouses
Before you begin building your foundation, decide if you will need to have power supplied to your building, often a panel built on a wooden frame or power from a nearby building. If you will be using a double layer inflation kit you will need a continuous power supply. Even if you don’t plan to have any automated electrical systems in your house, having electricity comes in handy for:
- Running fans when it gets hot
- Charging your phone
- Listening to music while you work
- Heated seedling mats
- Running space heaters
Anytime that water and electricity will exist in the same space it is doubly important to ensure the work is done safely and up to code. Unless you or a buddy is an experienced electrician, add the costs in labor of having the trenches dug, the supplies and an electrician’s time to your build estimate.
Ideal Soil Conditions for Building a Hoop House
Depending on your growing methods and planned crops, ideal soil conditions may vary. If you will be growing hydroponically the health of the underlying soil is not as much of a concern as worker comfort and proper drainage.
How do you prepare the ground for a greenhouse or hoop house foundation?
If you will be growing in the ground, a requirement for NRCS funded high tunnels, preparing the soil before you build your hoop house or high tunnel will help you get the most from your crops and crop rotation quickly during the growing season. Solarizing weeds, adding compost and amendments, building raised beds, and laying landscape fabric are all easier to do before the structure is built. For more on the Proper Use of Ground Covers on the Farm you can check out this article to choose what would work best for your upcoming growing season.
Know what was there before you. If your property housed previously toxic industry like salvage yards or a factory, you may not be able to grow in the ground safely.
There are a number of flooring options to go along with whatever type of foundation you choose.
The most common choices for flooring in hoop houses or greenhouses are:
- Compacted gravel/Crushed rock
- Pea Gravel
- Soil
- Raised Beds
- Concrete Slab
- Wood Floors
- Landscape fabric
Proper Ground Post Depth for Hoop House Style Greenhouses or High Tunnels
For our All-Metal Greenhouse Kits we use four foot tall pre drilled ground posts that are sunk two feet in the ground. This means you will need to know what the conditions are two feet below the surface of your soil. If you dig down a foot in your build site and run into shale or hardpan, you will need to plan for how to properly secure your posts.
If your soil conditions are less than ideal you may need to plan on using concrete or compacted gravel to hold your ground posts. We have covered everything you will need to know about sinking your ground posts for hoop houses in our article on Ground Posts and Hoops.
Guiding the Direction of Runoff and Drainage from Your Hoop House
When you prepare your site to build, ensure you know what direction water already flows on your property. We have known farmers that needed to build diversion dams to keep water from other parts of their property from pooling at the crown of their hoop houses.
There is also rainfall and irrigation runoff to be considered. Particularly for NRCS funded projects such as hoop houses, as you will be expected to show a plan for dealing with and mitigating any damage from water runoff. In some cases it may be necessary to install a French drain system around the perimeter of hoop houses to divert rainwater and any possible garden runoff from overwatering.
Is Your Farm Site Prepared for Your Hoop House Build?
If you have taken into consideration the locations of existing structures, the soil conditions, the existing grade of your site, and access to utilities before you build you will be prepared to build hoop houses or greenhouses. Planning into your budget for any accommodations and additions you will need to make to your site gives you a much more realistic idea of the true cost of building hoop houses. Read How to Attach Greenhouse Plastic to learn about the process of adding plastic covering with spring wire to hoop houses or if roll up sides should be consideration for the plastic cover.
None of this is intended to deter you from building diy hoop houses or high tunnel for season extension, but to ensure you are not surprised by costs along the way. We also want you to have a successful build that is ready for planting when you need it to be. Getting started on your hoop house site prep long before you plan to build will save you money year round and heartache in the long run. For a visual of how this process works check out, Site Prep How-To | Hoop House 101 Ep. 5.
Once you get this step done, it is time to consider shade cloth and plastic coverings commonly used on hoop houses and high tunnels. Read the Ultimate Guide to Ground Covers on the Farm for tips to use next spring and learn what a market gardener uses for covers on and below their hoop houses and high tunnels as a tool for season extension.