In previous articles, we took a look at a needs assessment, and greenhouse design and materials as two general areas of consideration for those of us trying to decide whether a greenhouse is a good place for our green thumb adventures. In this installment, I’d like to discuss location and orientation as two additional factors to consider. After all, you can have an intense desire for a greenhouse, but if you don’t have the space, can’t conveniently locate it, or you just can’t achieve proper orientation, it might not be advisable to purchase or build one.
Selecting a location for a greenhouse is usually not an issue for a commercial operator. Typically, they have sufficient land available to dedicate to their greenhouse gardening operations. So, let’s focus on homestead and homeowner gardeners with respect to greenhouse location.
First and foremost, it would be advisable to have your greenhouse conveniently located to your home. It probably won’t be as much fun if you have to walk 100 yards to get to your greenhouse, so having your garden a good distance from the house could be sufficiently discouraging to you. If you think about hiking out a good distance, each time you need to visit the greenhouse, nearly every task will become more of a chore. To minimize this effect, keep the distance between where you reside and where you garden as short as reasonably possible.
Consider for a moment, weather conditions and how they might influence your greenhouse gardening activities. Whether you are trying to start seedlings in the spring, harvest during the summer and fall, or push the envelope by harvesting well into the winter months, foul weather won’t be pleasant if you have to walk a great distance through it all to get to your greenhouse.
In my neck of the woods, we get snowdrifts that are completely impassable by any normal four-wheel drive vehicle. Those snowdrifts can occur between one of my greenhouses and my home. I don’t mind slogging through three-and-four-foot-high drifts that are 15 to 20 feet wide, but I wouldn’t be happy doing it for a distance of more than 30 to 50 feet. And that is why our “kitchen greenhouse” is within 20 feet of the house.
If your greenhouse will be a new construction project, you will want to provide water and electricity to support it. The farther away you place your greenhouse, the longer and more difficult your trenching efforts will be. So, consider the origins of essential resources like electricity and water when you consider the location of your indoor gardening space.
One last consideration with respect to locating your greenhouse; assume you are interested in a greenhouse that uses standard greenhouse film. Such material is susceptible to damage from animals, high winds, falling tree branches, and other human activity that might not be present when you make your initial site assessment. With this in mind, it should be clear that a greenhouse next to a ball field or other play area, or a greenhouse within the distance of windblown branches from nearby trees are both unwise choices. A location up on an especially windy ridge is also undesirable. To avoid unknowingly subjecting your greenhouse to hazards such as these, think through daily activities, normal and abnormal weather conditions, and generally envision a range of undesirable scenarios in your mind to see if any of them present an unreasonable hazard to your future greenhouse or the crops you intend to grow within it.
There are basically three schools of thought with respect to greenhouse orientation; 1) capture the morning sun; 2) capture the winter sun; and 3) orient plant growth instead of the building. For this discussion, let’s assume that you have a rectangular shape in mind for your gardening structure, since it is by far the most common greenhouse style.
Morning sunshine is important to stimulate growth, to remove condensation from leaves, and to get your plants off to a good start each day. This is typically the interest of greenhouse gardeners who focus their efforts on summer vegetables. If this is your interest, my suggestion is to orient your greenhouse in a North and South direction. Such an orientation promotes full capture of the morning sun and allows the sun’s rays to penetrate between your plants as it travels up and over the width of your greenhouse. This orientation assumes that your plantings are in rows oriented perpendicular to the length of the structure.
For those with an interest in fall, winter and spring greenhouse gardening, an orientation of the greenhouse in an East to West manner will make more sense. Such an orientation helps capture the sun’s rays that are much lower on the horizon during those times of the year.
The third approach to orientation is applicable to both summer and off-season gardeners, and for those of us who do not have an ideal location that would allow for our preferred orientation of the gardening structure. This approach requires that we orient our crops in a manner that we achieve our summer or off-season gardening objectives by understanding how the sun travels across the sky and through our greenhouse.
This is clearly a fallback position at best because growing crops diagonally in relationship to the greenhouse will not be convenient at all. In any event, a greenhouse gardener will want to plant crops in a manner as to eliminate tall plants shading shorter ones, and then orient the rows of plantings to best capture the sun, all the while being mindful that plant orientation and pathways in the greenhouse need to be convenient for the gardener.
Good Enough Sometimes
I don’t want to downplay the importance of location or orientation, but sometimes a compromise that seems good enough is, in fact, just that. As an example, if you live in some western and southern states, you might enjoy an abundance of sunshine. My experience in Wyoming suggests that even a poorly oriented greenhouse will still suffer from too much solar gain simply because in the average year more than 70 % of our days are sunny. Our biggest challenge here is venting the greenhouse during the summer so it doesn’t overheat. If you have a similar situation where you live, then perhaps orientation will not play such a crucial role in your success.
Likewise, if your greenhouse isn’t exactly convenient to your home, you might be able to overlook this simply because running water lines and electric lines will only be done once, and if you’re enthusiastic about your gardening pursuits, perhaps a little distance won’t be an issue. It’s up to the individual to decide when location and orientation is crucial to their success and continued enjoyment, and when a compromise is in order.
Clair Schwan is an avid vegetable gardener who considers his gardens to be important assets. To him, vegetables in the garden are a bit like money in the bank.