7 Reasons Polycarbonate Greenhouses are Proven to be the Best
Why choose a polycarbonate greenhouse?
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You have decided to finally build the greenhouse you have been dreaming about for years. You want polycarbonate. Your partner thinks a glass greenhouse is best. How to choose? Which truly is the best? What if you had all of the answers to your partners objections?
Polycarbonate greenhouses are my favorite. I freely and openly admit it. I would much prefer a polycarbonate greenhouse in my backyard to a glass greenhouse or polyfilm greenhouse. My hope is once you have read this you will feel the same way about building your greenhouse using polycarbonate greenhouse panels.
Better Insulation
These sheets offer better insulation than glass or polyfilm.
Twinwall Polycarbonate
A multiwall polycarbonate sheet has channels that run between two exterior sheets creating a higher R value. R value is the resistance to the passage of heat through the material.
I compare them to looking down the end of a cardboard box. You will have a sheet on the outside, a sheet on the inside and a rib that runs through between the sheets. The rib will be straight through in polycarbonate rather than wavy in corrugated cardboard.
This channel or “dead air space” will give a much higher R value (better insulation) than 6 mil polyfilm or tempered glass.
A 6 mil polyfilm will have about a 0.8 R value. Single glass has about a 0.95 R value and 8mm twinwall polycarbonate will have an R value of about 1.7.
The higher the R value the better the insulation. What this means to you is that you will use less energy and spend less money heating your greenhouse.
No Hot Spots
With glass roofs you may get hot spots in your greenhouse. Polycarbonate greenhouse panels, even the clear ones, will diffuse the light somewhat helping to eliminate this problem.
Easier to Install
Polycarbonate is easier to install than glass or polyfilm.
With polyfilm you have to be concerned with catching it on anything sharp on the frame and causing it to tear. Glass is heavier and some people just don’t like the thought of handling glass.
Polycarbonate sheets are lightweight and pretty forgiving as long as you leave room for contraction and expansion when installing. The standard rule of thumb is to leave 1/8” every 3′ for contraction and expansion.
Tough and Break Resistant
This glazing is virtually break proof. It has an impact resistance of roughly 200 times higher than glass. Most polycarbonate sheets used for greenhouses even have a ten year warranty against hail damage.
Glass, even if it is tempered glass, will break if hit right.
We had a customer we built a glass greenhouse for years ago. Every time he mowed his yard he called us back to replace a piece or two of glass. Eventually we recommended that he turn his mower in the opposite direction when mowing around his greenhouse. That was all it took! But still, it is expensive and sometimes difficult to replace tempered glass in a greenhouse.
If you have small children around you may want to take this into consideration when considering glass, polyfilm or polycarbonate. Accidents happen even when they are being careful. That football may not land exactly where it was planned to go. Glass and polyfilm greenhouses will not hold up to accidental errors.
UV protected greenhouse film will typically have a 4 year warranty on the UV protection, although there are different grades. But, you still have to be concerned with ripping, etc. Polycarbonate greenhouse sheets that are UV protected with have a ten to twenty year warranty, depending on the manufacturer.
More flexibility in design
When using polycarbonate sheets for your greenhouse you will have more flexibility in design that with glass or polyfilm.
Polycarbonate Sheets can be bent onsite.
You can bend these sheets on site with no tools if you follow the manufacturers minimum bending radius guidelines. It’s hard to do that with a piece of glass. You can bend glass, but it is expensive and companies that will do this are hard to find.
Less expensive than glass
The materials are less expensive than trying to locate tempered glass. And, they are readily available. Glass greenhouse kits will also be more expensive than polycarbonate greenhouse kits.
You also will have an excellent selection of greenhouse polycarbonate sheets of different thicknesses and different specialty coatings. These would include such properties as heat reduction for warmer climates, light deprivation panels for the marijuana industry and diffused light panels for just a general healthier plant.
Can be easier to move
Due to the panels being so lightweight it may be easier to move a polycarbonate greenhouse than a glass greenhouse. Of course this is going to depend on the size and framing materials used.
In Conclusion
I have always been a more function over form type of person. I am not as worried about the aesthetics of a product as I am about its ability to perform its duty.
That being said, if you want a clear view out of your greenhouse like looking through a window polycarbonate will probably not be for you. The rib that runs between the panels will distort your view somewhat. You will see colors but not details through the polycarbonate sheets.
After reading this I hope you are in agreement with me that polycarbonate greenhouses are the best. What do you think? Let me know in the comments if you prefer polycarbonate, polyfilm or glass greenhouses. Happy Growing! Tammy
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Growing in Your Greenhouse
You finally are getting the greenhouse of your dreams. Now you need to decide how to use it best for your needs. Growing in a greenhouse is not a cut and dry situation. We all have different crops, different climates, different styles of greenhouses, etc. The great part about growing in a greenhouse is that you learn something new every day.
Do not think that you need to load up your greenhouse with accessories when you first build it. A basic greenhouse setup will have some manner of ventilation, access to water and a heater if desired. Everything else can be added as the need arises.
Experiment with different growing methods if your crops permit it. You are not stuck to just one method. Here are 8 great different ways to grow in your greenhouse. And, you can use some of these in combination with other methods. You are not stuck just to one manner of growing.
Different methods of growing
Grow directly in the ground
Blossom of strawberry plants growing in outdoor greenhouse covered with plastic film
You can just dig directly in the ground as you would for your garden. Your greenhouse will provide cover, frost protection and maybe even heat depending on how you have set it up.
This is probably the least expensive way to grow in a greenhouse. Really all you need is a shovel to work the ground and markers to show where you planted your crops. You will need to take the same care as with your outside garden. Add compost when needed and rotate your crops.
Be careful with this: If you are growing heat loving plants in the winter the ground will not be as warm as your plants may like – even though you have the greenhouse heated.
Build raised garden beds
Growing tomatoes in raised beds inside your greenhouse.
You can build raised garden beds directly in your greenhouse the same as you would in your garden. The soil will be imported for this method. But, a soil mix in raised garden beds will give you better draining, less compacted soil than planting directly in the ground. Raised beds are easier to maintain than growing in the ground. Plus, you get a nice spot to sit on the edges of the bed and work your garden.
If you have a lean to greenhouse make sure that you are not building a raised bed directly against your home. You may add water to your foundation, just where you don’t want it.
Plant in pots or containers
Growing Plants in Containers in Greenhouse
Most plants will adapt to container planting well as long as you provide a large enough container. Make sure that they have holes to drain out the bottom. You will be using potting soil that is light and compact and will drain well.
Pots can be placed on benches in the greenhouse,or larger pots can be placed directly on the floor. If your greenhouse is large enough you can even grow some dwarf fruit trees in containers. If you have shade loving plants in containers you can place them under benches gaining 2 areas in one space.
Use hanging baskets
You can use hanging baskets in conjunction with any of the other systems you may choose. Just make sure that your greenhouse frame is built to hold the weight of the plants. Wet soil and plants can get heavier than you may think.
Make sure that the pots are set up with drain holes and make sure that the water will not drain onto anything below such as electrical systems or leaves of other plants. Water dripping on plants will deteriorate their health significantly. Plus, not to mention if you are growing plants to show. You won’t win with ugly water spots on your plants.
Growing in containers in greenhouse
Hydroponic systems
Grow with hydroponic systems in greenhouse
There are many different types of hydroponic systems you can use in a greenhouse. You can use dutch bucket systems on the floor of your greenhouse. Or, you can use a drip system or nutrient film technique with gutters. There are also ebb and flow systems that can be placed directly on the floor. These systems require you to monitor the nutrient balance, but they are an excellent system and pretty easy to use once you get used to the different growing method.
Aquaponic systems
Aquaponic systems can be set up like a hydroponic system only you use the waste from fish to feed the plants rather than a nutrient solution. Raft systems for growing lettuce are very popular.
Grow vertically
No matter what type of system you are using you will definitely get more use out of your space by growing vertically. This can be done in several different ways. You can build a frame like a step and place pots on it. Or, you can use a gutter system (hydroponic or soil) that is stacked in a staggered manner on top of each other. Planters that are designed to hold multiple plants in a vertical system are very popular for their space saving properties. Just make sure if you use one of these that all sides of the planter receive equal light. Or, make sure that you have it set up so that you can rotate the planter.
Grow by adding layers.
In an unheated greenhouse you can grow inside a cold frame for added weather protection. You can even place soil cables in the cold frames for totally pinpointed heat.
This helps you to grow without adding as much supplemental heating to the entire space of the greenhouse. It’s kind of like dressing in layers in the winter months. This also enables you to create some areas in your greenhouse with different climates.
Conclusion
No matter what growing system you use a greenhouse is a great place to grow vegetables for your family, over winter plants or house your prize winning orchids. Get busy experimenting today to see which system is the best for you.
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How to Grow Microgreens
Growing microgreens is fun and easy. Missing your fresh greens? Looking for a fun project to do with the kids? While you are at it why not grow some mushrooms as well?
What are microgreens?
Pretty much anything can be grown as a microgreen. To be qualified as a microgreen a plant is harvested when the first true leaf unfolds. Do not confuse the cotyledon as the first leaf. This is part of the embryo in the seed of the plant. It gives plants the burst of energy needed to form the first true leaves. It is totally edible.
Cotyledon vs First True leaves
Microgreen Seeds
There is no need to use special seeds for microgreens, but I prefer to use seeds that are non GMO, organic and have a high germination rate. You do need to watch out for several things using garden seeds. Some garden seeds have been treated with special chemicals. There are supposed to break down after planting so that they do not enter the plants.
But microgreens are eaten shortly after planting, so there may not be time for these agents to dissipate. Also, there are certain plants such as eggplant and tomatoes that cannot be used for microgreens. I feel much better using seeds that are labeled for the growing method I will be using, even though they will be more expensive.
Why grow microgreens?
There are several reasons to grow microgreens.
They are up to 9 times more nutritious than mature greens.
They go from seed to harvest in 1 – 3 weeks.
You do not need any special equipment or large spaces to grow them.
They rarely get pests due to the short amount of growing time.
There is no need for fertilizer.
Great addition for sandwiches, stir fry or salads.
What can be grown as a microgreen?
Arugula
Radish
Mustard
Kale
Watercress
Swiss Chard
Basil
Dill
Cilantro
Peas
Spinach
Lettuce
Salad Greens
Endive
Beet Greens
And Many More.
What equipment do I need?
A flat, shallow container approximately 2” deep. This could even be a recycled container, as long as it has been cleaned and disinfected. You should always have holes in the bottom of your container. You may choose to use a single use hydroponic mat rather than a container and soil.
A cover for your container.
Potting mix.
You may want to use a propagation mat, although it is not required. If you do use one remove it once the seeds have germinated.
You may need supplemental lighting if you are growing indoors and don’t have a sunny windowsill.
A spray bottle for watering.
Growing Microgreens in soil
Microgreens can be grown indoors, in your garden or in your greenhouse.
Dampen your soil.
Fill your container with dampened soil
Sprinkle the seeds over the soil. They should be packed pretty tight and about 1/8” to ¼” apart.
Cover the seeds lightly with about 1/8” soil.
Water gently, but thoroughly.
Cover container with a lid.
Water with a spray bottle once or twice a day.
Remove the cover a couple of days after the seeds have germinated.
Keep in sunlight or under artificial lighting for 12 – 16 hours per day. A sunny windowsill may work for this. If you are growing in your greenhouse you should have no need for additional lighting unless it is late fall, winter or early spring when natural lighting is low.
Keep watering at least once a day.
Harvest after the first true leaves have appeared by cutting the microgreens at soil level. THs is typically from 1 – 3 weeks depending on what you are growing. The plants will be between 1” to 3” tall.
Growing Microgreens Hydroponically
You will get a cleaner harvest growing hydroponically as there is no soil. Some plants such as basil grow low to the ground and are hard to harvest and keep clean.
Most hydroponic pads are single use. They will either lose their ability to absorb water, or they will just fall apart after a single use. The ones made from wood fiber make a great addition to your compost pile.
You will still need a tray to place the mats inside. Also, growing microgreens in this manner does require fertilizer or nutrients which are mixed with your water.
Make sure your water is at a pH of 5.5 to 6.5.
Soak your mat in your nutrient solution, let it drain and place in your flat tray with holes in the bottom.
Sprinkle your seeds over the mat spaced according to the directions on the packet.
Mist with fresh water.
Cover your tray.
Mist twice a day.
After 5 days remove the cover and place in a sunny windowsill or under artificial lighting.
Keep watering plants daily.
At 1 -3 weeks when they are ready to harvest cut them off the mat with a pair of scissors.
Growing Microgreens for Profit
Growing microgreens can be quite profitable. With the minimal equipment and small amount of space required your overhead is low. Add to that the fact that microgreens sell for a premium price. Just be sure, as with any business venture, that you find your market, how much it will use and what it is willing to pay before you ever start growing. Do your homework!
If you are going to be selling your microgreens and doing live deliveries, you will have to use a hydroponic growing method to sell to restaurants. They are not permitted to have any soil in the kitchen. But if you are harvesting the microgreens before delivery you can grow them using any method you prefer.
In Conclusion
Growing microgreens is fast and simple. Add to that the great nutritional value and you have a winning combination. Try some today! Let us know about your microgreen growing experiences in the comments below.
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We have been gardening with plastic mulch for close to 20 years now. And yes, that is a picture of my personal garden several years back. I am so glad that we found it. Our garden is healthier, more productive and easier to manage. Plus, it cuts our water bill way down.
We have changed the way we use the plastic mulch through the years. At first, we just mounded up our beds and put the mulch over the dirt – no edging. We used ground staples and placed a brick on each staple. The previous homeowner had left a big pile of bricks that we used.
Now we have raised beds edged with concrete blocks. The first couple of years we only had one row of blocks (see picture of my garden below). We have since increased that to 2 rows with a concrete cap on top. It makes It easier to kneel and to just sit down and garden. We still use the ground staples. We place them at 18” spacing. Then we place rebar on the edges all the way along the raised bed.
Plastic Garden Mulch
No matter which way we used we have never had any mulch blow off the beds. It stays nice and secure especially when the plants start growing and you put cages around them.
Benefits of Plastic Garden Mulch
I don’t have any scientific evidence, but our plants are pretty much disease and pest free. I can’t remember the last time we had an issue. We did have some tomato hornworms for a couple of years, but they have been gone now for years.
Water is conserved. Evaporation is slowed due to the plastic mulch. Therefore, you do not have to water as long or as frequently. Please note that water will not pass through the mulch so you will need a watering system underneath it. We use a Drip Tape System on a timer. Even in the hotter summer months we only water for 30 minutes every other day. You should determine your own watering schedule based on your plants and their needs.
Weeds are kept at bay. Now, I am not saying that there are zero weeds if you use this method. You are making holes where you are putting the ground staples through and where you are planting your seedlings or seeds. Also, it is just about impossible to get it tight to all the edging. So naturally weeds will peek through at these spots. When we just mounded our dirt, we did not have problems at the sides. It is still a whole lot less labor intensive than weeding an entire garden.
Yields will be higher, and plants will start producing earlier. Some of this can be attributed to the light that is reflected off certain colors of the mulch.
Warmer soil. The plastic mulch will warm the soil in the garden. This leads to faster plant growth.
Nutrients will remain in the soil and not leach out due to excess rains.
What color is best?
There are several different colors of mulch available for different plants and climates.
White on black mulch – This has always been our choice as we are in the South. The white on top helps keep the soil cooler than a black on black mulch. This can decrease the soil temperature as much as 12 degrees F.
Red mulch – This is excellent for tomatoes and strawberries. Red light is reflected back to the plants. This is useful in increasing photosynthesis capabilities. This color will increase the soil temperature 4 to 6 degrees F.
Blue mulch – This is good for cucumbers, squash and melons. This will increase the soil temperature slightly more than the black.
Black mulch – This can be used for warm season and cool season crops. At a level of 2” to 6” the soil temperature will be increased 3 degrees to 5 degrees F.
Metallic mulch – This is thought to help control pests. It has been shown to reduce aphids and whiteflies. It is believed that the metallic sheen confuses the insects.
Installing plastic garden mulch
When it is planting time, you should work your soil as you normally would.
We use a small tiller and then level out our soil with a rake.
Set up your watering system and check it for leaks.
Roll out your mulch and secure it with ground staples and any other weights you may choose to use.
Plant
We have found a method of rolling out the mulch that works best for us. We place the roll at one end of the bed and place the good side up. We have one person on each side of the bed. We then roll it out about 10 feet. We then place our ground staples at approximately 18”. Then we just repeat until we reach the end of the row. Once we have placed enough ground staples for our rebar to fit we will place it over the top of the mulch on the edges. We have found that just rolling it out like this, a little bit at a time, allows us to put our mulch down even on windy days. The wind always seems to kick up in the Spring just as we are getting ready to put our mulch down. It never fails.
Plastic garden mulch is only good for one year. You will remove it and dispose of it once the season is over. You will be rotating your crops and will need different spacing of the holes next season.
We have always used ground cover in our walkways. This gives us a nice (almost) maintenance free garden. The ground cover will last 5 or 6 years even being walked on daily.
Conclusion
Plastic garden mulch is one of the best innovations for gardeners. It helps us keep a healthy, clean, high producing garden. I am glad that I found it when I did. I would never go back to gardening without it. Share your experiences with us in the comments below.
Which thickness, color, etc should I choose? This is a question that I get asked regularly. It was not so difficult in 1993 when we started dealing with polycarbonate. We had a local business where we sold and installed at that time. We were in the South, so all our projects were done with 8mm clear twinwall. There really were only 2 options readily available at that time – 8mm twinwall and 16mm triplewall. Mostly the 8mm was used in warmer climates and 16mm was used in cooler climates. But all that has changed now.
Always be sure to use polycarbonate sheets that are UV protected one side for any outdoors project such as a greenhouse, patio cover, etc. That is what contributes to the longevity of the sheets.
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What sheets are available?
Today you can get polycarbonate sheets in 6mm (1/4”), 8mm (5/16”), 10mm (3/8”) 16mm (5/8”) and 25mm (1”). Sheets are available in clear, opal, bronze and specialty coatings. These specialty coatings provide properties such as diffused light. I will break it down more sheet by sheet.
What is the difference between the thicknesses?
The different thicknesses will have different properties such as light transmission, etc. But the difference is also in the amount of framing you will need under the sheets. The strength in your structure is really coming from the framing, not so much from the sheets.
You should be able to get a chart like the one below from the dealer you are working with. This will show you the purlin spacing in a rafter and purlin roof design. You will see that as the snow load goes up the frame spacing can be further apart for the thicker sheets.
Purlin Spacing for Polycarbonate Sheets
Also, the thicker the sheet and the more walls – the higher the R value or insulation factor. If you are in an area where heating costs are a concern you will want to get the highest R value for your budget. That is unless you do not plan on heating your greenhouse in the winter. Then the R value is not that much of a consideration.
What is the difference between the colors?
Clear sheets will have the most light transmission and are the choice for a greenhouse unless you are using a specialty sheet such as Polymatte, Polycoolite, Lexan Softlite or Polisoft. These preceding 4 named sheets all supply 100% light diffusion with a light transmission comparable to clear. With 100% light diffusion the light is spread so that it reaches all parts of the plant equally, even under the plant canopy. This leads to higher production and a healthier plant.
Opal and bronze sheets do not have enough light transmission for a greenhouse unless you are growing plants with low light requirements. They are better off being used for patio or pergola covers. Remember, if you are covering a pergola the sheets need at least a 1 on 12 roof pitch. You cannot lay them flat.
Which thickness should I use?
Now you not only need to consider the thickness you will also have the option of how many walls. A twinwall sheet has two sheets on the outside with a rib running straight between them. A triplewall sheet will have an interior wall running parallel to the two exterior sheets. Also, when you get into polycarbonate sheets with 5 or more walls you may sometimes have an X shaped configuration.
6mm twinwall – This is an excellent choice for a patio cover, etc as you are not so worried about a higher R value on this project. It is also an excellent choice for a greenhouse in a warmer climate. Although I prefer the 8mm twinwall as it typically has an anticondensate coating on it. This is a coating that allows condensation to sheet off rather than come off in droplets. Healthier plants are the result of this. But, if the budget does not permit the 8mm, the 6mm is your next best bet.
8mm twinwall or triplewall – This is my choice for greenhouse glazing in a warm climate. It has the anticondensate coating as previously mentioned and all the profiles are readily available for it. The 8mm triplewall will have a higher R value than the 8mm twinwall. It will be a comparable value to a 10mm twinwall sheet.
10mm twinwall or triplewall – 10mm sheets do not require framing to be spaced as close as the 8mm sheets. So, if you are in a moderate climate with a small amount of snow this would be an option to consider. The triplewall sheets will have a higher R value than the twinwall sheets.
16mm triplewall or 5 wall – These are both excellent options for greenhouses for cold weather climates with a heavier snow load. Remember to build your frame with appropriate spacing as per the chart above. The 5 wall will have a higher R value than the triplewall.
16mm 5 wall polycarbonate
25mm 3 wall – If you want to go even higher with the R value, this would be your choice. Please keep in mind though that typically you will have to use the aluminum profiles with this sheet. Polycarbonate profiles for 25mm are not readily available. The only real difference in the profiles is the look and the fact that the pricing will be higher for the aluminum. Just keep that in mind when you are looking at your budget.
Conclusion
Polycarbonate can be difficult to work with the first time you are using it. I think that most people tend to over think it some. There are a few basic installation rules that you must follow, but it is not all that complicated. There are a lot of options today and a lot of decisions to be made, more than when we started using it. Hopefully this breakdown will simplify this process for you. The biggest mistake is getting overwhelmed before you start and not getting your project done. So just take it step by step and enjoy your greenhouse when it is completed!
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approximately 2” deep. This could even be a recycled container, as long as it has been cleaned and disinfected. You should always have holes in the bottom of your container. You may choose to use a single use hydroponic mat rather than a container and soil.
if you are growing indoors and don’t have a sunny windowsill.
on a timer. Even in the hotter summer months we only water for 30 minutes every other day. You should determine your own watering schedule based on your plants and their needs.
