Greenhouse Siting, Ground, Alignment, Maintenance, and Utilities
When siting greenhouses the advice is to choose a site where it will catch most sunlight, particularly during late winter and early spring when seedlings will be starting to grow and will need as much daylight as possible.
Avoid any low-lying ground that is prone to becoming a frost pocket or may be susceptible to getting waterlogged.
Ideally you want the land to be well drained and not boggy.
If you are siting a poly tunnel and intend to plant directly into the soil, try to site it where there is sufficient depth of soil and remove any rocks prior to erection.
There seems to be some difference of opinion on the preferred alignment of a garden greenhouse, east-west or north-south. Depending on how large your garden is you may not have a huge choice about which direction you align the greenhouse and the advice on this seems to be different in different countries depending on a variety of things such as the climate and prevailing winds.
If it is possible you should choose a position that will be sheltered from cold winds, you particularly do not want the door facing into the most likely cold wind direction, and remember that north facing land will not get as much sunlight or be as warm as south facing.
I would suggest that you follow advice given for siting greenhouses in your country. I have noted for example that if you live in a hot country you might like to take advantage of the direction of cool winds going into the vents and door, whereas if you are in a cold country you would want to avoid that as the whole purpose of the greenhouse will be to warm up the environment to grow plants not cool it down!
For example, siting a greenhouse in the northern hemisphere such as the UK, an east-west direction would get the maximum benefit from the lower winter sun and therefore likely be the most popular choice in that country.
If you haven’t got very much space in your garden and will ultimately have some shadow cast by trees, buildings, walls and fencing, bear in mind that these things will create a longer shadow during winter months and reduced length shadows in the summer. You don’t want your greenhouse to be in shade all day so the further away from anything that will cast a shadow the better.
If you are siting greenhouses during the summer months you must not forget to take note of potential shading caused during the winter months when the shadows will be longer.
Deciduous trees will have lost their leaves in the winter so those shadows will not completely block out all light. However, do be aware of lighting and shading issues when choosing your site. Trees and hedges can be trimmed, pruned, thinned out to let more light through if you really have no choice of siting a long distance from them.
Be aware that if your plants do not get enough light they will not grow as strong or as quick and will likely be spindly and weak. So unless you intend to use artificial lighting this is really important. Plants need sunlight!
In the case of too much sunlight, please see my page on Greenhouse Shade for information about blinds, shade cloth, and shade washes etc.
If you are siting greenhouses near the vicinity of fencing, walls, ditches, vegetation, do remember that you will need some space all around the structure in order to be able to carry out maintenance when needed.
If you want to lay on a water supply and electricity to your greenhouse you should ideally site your greenhouse as close to your house as possible for convenience and to lower the cost of installing electric and water. Even if you can’t afford water and electricity supplies initially, having the greenhouse sited near to your house does give you that option for management improvements later on.
You can also put down a solid path to the greenhouse from your home as it will likely be well used.