Greenhouses - a valuable resource

Greenhouses are a valuable resource for those of us that are serious about vegetable gardening. I've gardened for years in open sun beds, but my experiences with vegetable gardening inside these wonderful protective structures has convinced me that they are the best way to go.

But, only if you're serious about growing lots of quality vegetables.

You'll want to carefully consider the advantages and disadvantages of such a resource before you jump in with both feet.

If you live in a climate that has cold weather, high winds or intense blistering sun and heat, greenhouses might just be the thing you need to support your vegetable gardening interests.

I have three greenhouses here in Wyoming and they allow me to grow vegetables with a level of success that is unheard of around here. Our drying winds take a lot out of our gardens, but the protective structure of a green house allows us to garden as if there weren't any winds begin at all.

If you're new to this, check out what is a green house to understand the basics. We're talking about an investment here, so you want to be certain that what you're likely to get back makes the investment worthwhile. My green house vegetable gardening mission is to:

• eliminate the ever increasing produce bill;
• have superb nutrition;
• enjoy pure organic produce;
• take control of my food supply;
• grow and harvest fresh vegetables year round; and,
• be more self-sufficient

Here is an overview of how a green house works to protect your plants and help you extend the gardening season to a year round effort. It's really quite an ingenious device to fully support the idea of local quality food.

Allow me to walk you through a structured thought process that might help you decide whether a green house is right for you, and what type of green house that might be. Let's discuss the essentials of purpose; location and orientation; size; design and materials; kit or homemade; and, features. That ought to cover it.

Your Indoor Gardening Purpose

I'll assume that you're here because you want to grow vegetables, but growing house plants and flowers is okay too. Let's focus on vegetable gardening for now, understanding that you'll probably want to squeeze in some nice flowers at some point.

One of the first steps is to decide what the purpose of your greenhouse will be. I'll show you my thinking as an example. I thought about greenhouse gardening for years before I took the plunge. I'm glad I thought about it for a while, and even happier that I jumped in.

Here are 10 reasons (in no particular order) that I own and operate greenhouses:

1. support vegetable gardening year round
2. make me independent of the marketplace with respect to produce
3. grow a wider variety of produce than commercially available
4. make certain that all my food is organic
5. defend against a harsh environment here in Wyoming
6. have a robust green house vegetable production for fresh vegetable consumption, as well as canning, freezing, drying and cold storage
7. supplement food for my small flock of chickens
8. bring back memories of wonderful fresh vegetables from my childhood
9. reduce the cost of feeding myself
10. satisfy my interest in being more self-sufficient

You'll have your own set of reasons. You don't need to have 10 of them either, but you should have more than a few. It's an investment, so you'll need to make certain the "return" is worth the time, effort and money that you'll invest to make it happen.

Make the purpose of your green house clear to you. If it's not clear, then it will be more challenging to determine location, orientation, size, design and features.

My structures are meant to maximize summer vegetable gardening, and allow winter gardening as well. My primary focus is to create an alternative to the commercial marketplace, so I have to be able to grow and harvest nearly year round.

This helps me determine the orientation of the structures to provide good winter sunshine.

The other main purpose is to provide plenty of food in the off season through canning, freezing, drying and cold storage.With that in mind, I know that the structures have to be of good size. I can't make do with a small structure or something that is oriented towards a hobby.

But perhaps you can. Here is a sampling of the types of greenhouses that are available to choose from:

• commercial kits that you build yourself or with a little help
• mini greenhouses to fit in your backyard
• portable greenhouses that can be moved around in your garden as needed
• small structures for weekenders and hobbyists
• so-called solar green houses which really describes the approach to heating used in a passive solar green house.
• DIY projects like my second and third greenhouses
• PVC greenhouses like my neighbors built
• indoor greenhouses for, well, inside the house
• small protective gardening structures
• a substantial wooden green house like my friends built
• patio greenhouses for limited applications
• cheap green house structures like my converted chicken coop

My first "kitchen" green house was created in support of the purposes noted above, and it was also a way to utilize an outbuilding that otherwise was going to waste. It was ideally situated on the property, so it made perfect sense.

I didn't build the structure because I had an outbuilding going to waste; I built it because I wanted a green house and the under-utilized outbuilding was ideal size, in the right location, and perfectly oriented.

Appropriate Location and Orientation

They say in real estate that the three most important things about your purchase are location, location, location. It's similar with a green house - you'll want to make certain that your location is ideal, or nearly so, and that includes orientation as well.

The main idea about location is to make certain you get sufficient sunshine. I'm interested in getting good sun during the winter, so my structures are located where there is little or no shade in the winter.

When considering location, you might consider the following factors:

• Is it conducive to solar gain during most of the day?
• Will shading be a problem?
• Is it convenient with respect to the house?
• Are water and electricity nearby?
• Are there other hazards such as overhead wires or sports activities that will be drawbacks?

Orientation is also an issue to consider. My interests focus on cold climate gardening, so I orient my structures lengthwise east to west to maximize southern exposure. If you're primarily interested in the summer growing season, you'll want to maximize morning sun by orienting them lengthwise north and south.

Size

I don't mean to dredge up the old joke about how size matters, but when it comes to greenhouse gardening, it really does. One of the worst things you can do is have a structure that is too small. Here's why:

• It won't support your purpose.
• You'll be uncomfortable when planting, working and harvesting.
• Your options for expanded usage will be limited.
• Soon you'll need to invest in a second and larger structure.
• You won't be able to dedicate space for relaxation and enjoyment.

It's better to have an adequately sized structure to start with, unless you really want multiple structures dedicated to specific purposes. For example, growing melons and cucumbers together can lead to foul tasting melons due to cross pollination, so a separate "melon house" might be in order.

I have three greenhouses, the footprints of their potential growing space in square feet are: 450, 216 and 1240. Each are plenty big by themselves and together they total a little over 1900 square feet of area dedicated to vegetable gardening.

Based on those dimensions, one might conclude that I'm trying to put all of my vegetable gardening inside of greenhouses. That conclusion would be correct. I need to if I'm going to enjoy the privacy, low population density and low tax burden of Wyoming, and still be able to have a bountiful vegetable gardens year round.

Only the largest of the structures will allow me to dedicate space for a table and chairs to relax and enjoy my surroundings. The other structures are pretty much dedicated to cranking out produce. There's room for a lawn or beach chair, but that's about it.

Get a larger green house than you envision necessary, and you'll enjoy more comfort and flexibility with your vegetable gardening.

Design and Materials

The issue of design is mostly a matter of style. Decide what style you like, and go for it. If you're blending this into your suburban neighborhood, you might want to go for something that looks more like a traditional greenhouse with glass panes, fancy ornamental trim, and a shape that is appealing to the eye.

These type of structures are very appealing to be sure, but just be prepared to pay for it as well. Most of these type of structures will be in the $10,000 to $30,000 range.

With respect to design, there are two main points to consider:

1. usable square footage for vegetable gardening
2. layout

A 200 square foot green house (10 feet by 20 feet) may sound like it's adequate, but how much space do you have for vegetable gardening when your pathways consume about 60 square feet (3 feet by 20 feet) of that?

If you're going to have an "A-frame" design that provides 400 square feet of growing space (20 feet by 20 feet), be aware that much of the ground near the sides will only be useful for growing root crops and other low growing vegetables. And, it will always be an uncomfortable place to work, so it will largely go unused.

Assuming that 3 feet in from the sides will go unused, there goes 120 square feet of growing space before you even get started. Subtract another 60 square feet for a 3 foot wide pathway down the middle of the 20 foot structure, and you wind up with only a little over half the square footage for vegetable gardening.

That's a lot less room than you thought you were going to have to begin with.

Materials are another consideration. The frame can be steel, PVC, rebar or wood, and the glazing is most commonly poly film, polycarbonate or glass. Here is a brief discussion of the materials.

Structural Materials

Common materials used for structural members of a green house include:

• Steel - it's strong and long-lived, and a good value for the money.

• Aluminum - known for strength, lightweight and long-lived, but a bit pricey.

• PVC - it's strong, cheap and easy to work with, but with a limited lifespan and less "sex appeal."

• Rebar - this material costs very little, but it's awkward to fasten together, and makes for a flimsy material for serious long lifespan structures.

• Wood - this common material is strong, lightweight, easy to work with and reasonably long-lived, but requires treatment and is susceptible to rot in a humid growing environment.

Materials for Glazing

Common materials used to create glazing for greenhouses include:

• Poly film - cheap and easy to apply, but requires periodic replacement.

• Polycarbonate - strong, long lasting and can provide insulation when purchased in double and triple wall configuration, but it's expensive.

• Glass - the original glazing that is strong, but heavy, costly, dangerous overhead, and very unforgiving with respect to hail, rocks thrown up by lawn mowers, and baseballs.

Buy a Kit or Do-it-Yourself?

Another decision to make is whether to use a kit or build something of your own design. Both are reasonable options, depending on the time and money you have available to dedicate to the project.

All three of my structures are homemade. For me, it's the way to go. I have time on my hands and feel better about having designed and constructed something myself. I wouldn't build my own home, but a a gardening structure is something a bit different.

Choosing to build my own green house is mainly a matter of wanting something that was very sturdy and glazed with woven poly. Both are necessary to withstand the strong winds and hail that we have here in Cheyenne.

Greenhouse kits are available through a variety of sources, and you can choose from many designs and a variety of glazing materials. The main advantage of a greenhouse kit is that the work is mainly a matter of putting the thing together.

With greenhouse kits, the product is tested and known to be viable for a wide range of climates and weather conditions. If you have special needs, you might consider enhancing the structure. Some kits come with additional structural members as an option.

For example, if you have a high tunnel design, you can designate as many "ribs" or "bows" as you think necessary to get the strength you want from the structure. Some tunnels come with ribs that are 6 foot on center, but you might want feel better with 4 foot on center. If you pay more money, and you get the additional materials for a stronger structure.

Features

Briefly, let's talk about features of greenhouses that you might find necessary or at least useful. It's perfectly fine to have a simple gardening structure with few if any of the features mentioned below. It all depends on what you want in terms of convenience, comfort and flexibility.

Many of us would like electricity in our greenhouses. It's down right handy for ventilation, circulation and lighting. If you're doing drilling, digging, constructing, painting and other chores, many times electricity will allow you to use power tools.

Another common feature is water and we all know that this is essential. You can have a hydrant or spigot outside the structure, but that can be rather inconvenient except for some of the smaller structures.

One of my greenhouses has a hydrant inside, and the other two have a hydrant just outside that allows water to be piped into the structures via the drip system. I lift the handle on the outside hydrant and open vales inside the greenhouse to direct water where I want it.

Another useful feature is greenhouse lighting. I consider this to be entirely optional. My feeling is that if I often find myself vegetable gardening in the dark, then I probably should do something about my schedule. Even if you work full-time during the week, it seems that weekends should allow enough time to get done what needs to be done during hours when even an overcast sky will light up the interior of greenhouses.

If you intend to grow seedlings, then having lighting out there makes good sense because seedlings will demand more light than the normal short days of the late winter will provide. And, this is usually when you're starting seedlings. In this case, supplemental lighting will be required.

A feature that we most often think about is greenhouse heating. Indeed, the heated structure is what most of us come to expect. Heating is a must if you're going to challenge Mother Nature, but it's optional if you'd rather "go with the flow" and raise cold hardy and winter vegetables during cold weather.

Keeping greenhouses cool is sometimes a challenge. Forced ventilation is one approach you can use. This involves vents and exhaust fans that operate on temperature switches. You set the temperature for each circuit and the vents and fans open/start accordingly.

One of my greenhouses has the vent open on elevated temperature, and the exhaust fan starts at a higher temperature. This requires two temperature switches, one wired to the vent circuit and another wired to the exhaust fan circuit.

Another structure of mine has the exhaust fan and vents opening at the same time. One temperature switch operates two vents and the exhaust fan simultaneously with a single circuit.

As an alternative, you could have manual ventilation with vents and roll-up sides. If you're going to be around when your greenhouses need to be vented, this is a good option to save costs on electricity.

Note that if you have a single film greenhouse in an environment with lots of sun, your vents and fans could be operating often to cool down the interior. And, on a hot day, they'll be running all day long.

Systems for misting and fogging are also an option to keep things cool inside. Unless you live in an exceptionally warm environment, these systems won't be necessary.

To keep the air circulating inside large greenhouses, ventilation might not be enough. You might need circulating fans to help accomplish this task. Stagnant air is what bugs and disease need to get a foothold, so having decent air exchange is important. If your structure is over 1000 square feet, you might consider having a circulating fan.

Decision Time

Take your time and think carefully about what you would like to accomplish with your vegetable gardening, then consider how greenhouses might support your interests. Only then will you be ready to make a decision based on reason instead of emotions.

Remember, greenhouses are an investment, so you'll want to make certain that whatever you choose will provide good return in support of your vegetable gardening interests.

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