Updated at: 21-10-2022 - By: Sienna Lewis

What is the hardiness zone in greenhouse growing? This question refers to the climatic conditions of the area and must be asked before planting. Whether you’re growing veggies or exotic flowers, knowing your location’s hardiness zone is critical to the growth and survival of your plants. The hardiness zone is important in greenhouse cultivation since it tells you what alterations you need to make inside.

In addition, you can anticipate and plan for future issues throughout the year. Because each crop and plant has a unique set of growing conditions, it is imperative that you keep an eye on the greenhouse and make adjustments as needed. Species and cultivars can be more easily selected depending on their hardiness and your state’s hardiness zone.

What Is The Hardiness Zone In Greenhouse Growing And How To Use It

What is a hardiness zone?

Hardiness zones, growth zones and planting zones can help you determine the average annual lowest temperature in your state or region. For farms and gardeners, it’s more important to know the lowest temperature ever recorded or what temperature might occur in the future than this. The USDA Plant Hardiness Zone Map was designed by the United States Department of Agriculture to make it easier for you to identify your hardiness zone.

The USDA plant hardiness zone map can be divided into thirteen 10°F zones and five 5°F subzones in total. It is possible to classify North America into 13 separate hardiness zones, each with a unique set of temperature and climate characteristics. Each zone is distinct, but how?

Zone 1 is the coldest, while zone 13 is the hottest of the 13 climate zones. To put it another way: You’ll notice a 10°F difference between the two zones. With this information, it is possible to select the appropriate plants for each zone, and all crops will be able to thrive.

However, don’t be shocked if some plants are able to grow in multiple hardiness zones. Other concerns, including as unexpected temperature changes, sun exposure, moisture, frost, soil quality, the plants themselves, and maintenance must also be considered if you’re growing in a greenhouse. Finally, before beginning greenhouse gardening, you will need to become familiar with the many microclimates that exist within each of the designated zones.

How to use a hardiness zone for greenhouse growing?

Choosing plants

The hardiness zone can also be used to choose and run greenhouses. The location, glazing, size, and greenhouse materials can all be figured out if you know what to expect from the weather. As an example, how well you plan for the winter affects how you choose and operate a greenhouse in USDA zone 4.

Adjusting the greenhouse conditions

It’s possible to grow plants in a greenhouse even if you live outside the appropriate hardiness zone. Improved temperatures can be a means of mimicking the ideal conditions for their development. In order to ensure the life of the plant, it is necessary to emphasize the role played by additional elements.

What Is The Hardiness Zone In Greenhouse Growing - Krostrade

Zones 6 to 10 predominate in the Southeast, for example. The soils in this area are similarly susceptible to heavy clay. In addition to selecting native plants, you should also consider the soil type and look for plants that can survive there.

Choosing and operating the greenhouse

The hardiness zone can also be used to choose and run greenhouses. Understanding the basic circumstances will help you choose the location, glazing, size, and greenhouse materials for the project. As an example, how well you plan for the winter affects how you choose and operate a greenhouse in USDA zone 4.

What Challenges To Expect On Each Hardiness Zone?

Zones 1 and 2 have particularly chilly winters, which might make growth in a greenhouse difficult. Windy conditions can be seen in Zone 3, and the growing seasons in Zones 4 and 5 can be particularly short. Most of the United States is classified as Zone 6, which means you’ll have a wider range of cultivars to choose from because it’s more tolerant.

In addition, zone 7 offers a wide variety of plants, while zone 8’s hot summer and moderate winter allow for a longer growing season. It’s easy to grow year-round if you live in zone 9. Zone 10 is susceptible to the effects of severe heat.

All of Hawaii, Puerto Rico, and sections of the continental United States are in Zones 11 to 13. Zone 11 is exempt from frost, however zones 12 and 13 are subject to extreme heat.

Discover Your Planting Zone

An estimate of the best plants to grow in a certain area is provided by planting zones. Your local nursery can provide you with more specifics on what types of plants are most likely to survive the winter in your location and when to plant them.

Zones are divided into thirteen in the United States and eight in Canada. Zone 1 is the coldest in the United States, while Zone 13 is the hottest in the year. Temperature ranges alone aren’t taken into account by the system in Canada because of seven different climate variables that are taken into consideration.

How to Find Your Planting Zone

A plant hardiness zone map, such as the one provided by the USDA, is an excellent starting point for learning about plant hardiness zones and the best plants for your area in the United States. In addition, you can narrow your search by state or province.

To find your planting zone in Canada, take a look at a Canadian plant hardiness zone map. Match the colour of your region to the shade on the scale to learn about the specific zone of your province.

Why Planting Zones Matter?

Using planting zones will help you choose which plants are most suited to your area’s climate. Your ability to preserve your plants and produce a thriving garden will be enhanced if you know your planting zone.

Depending on where you live, you can choose whether or not a greenhouse is the best option for your gardening needs.

What is Plant Hardiness, and Why Does It Matter?

Measures the plant’s ability to cope with harsh growing conditions, such as drought. In times of drought, flooding, heat, and cold, it may be able to determine how well the plant can survive. Particularly for cold-climate adaptation, plant genetics can have a significant impact on how long a plant will live.

Each plant thrives in a specific environment. Soil conditions and plant exposure to sunshine, for example, are things you can influence. In contrast, the only way to regulate the temperature of your plants is to construct a greenhouse where you have complete control over every aspect of their growth. A greenhouse is the best way to extend your growing season if you wish to cultivate plants that aren’t hardy enough to survive in your existing environment.

How to Use Your Planting Zone

In order to get the most out of your gardening efforts, you need to know what kind of plants can thrive in your area and when to plant them.

1. Get to know your planting zone.

Observe your garden’s average temperatures and see what they reveal. The ideal time to plant in your area may be determined by your planting zone. If you live in Zone 1, you should wait until mid-June to start planting, however if you live in Zone 11, you can start planting whenever you wish.

2. Look into any other factors that may impact plant hardiness.

Despite the fact that knowing your planting zone can have a significant impact on what and when you plant, it is also important to be familiar with your local area and other aspects that may impact hardiness. These include soil conditions, general weather, and sunlight.

3. Check the list of the best plants for your area.

Your planting zone can help you determine which plants are most suited for your area, which can help you select plants that will thrive and survive in your garden more successfully.

What a Planting Zone is NOT

A planting zone is a wonderful way to determine which plants will thrive in your current area. A planting zone, on the other hand, cannot tell you everything.

  • Specific dates for the first frost in your area.
  • Soil conditions in your location and how well a plant will grow there
  • Your plants will be affected by the weather patterns in your area over the course of the year.

However, planting zones are not absolute, therefore it is vital that you also take into account other criteria when choosing which planting zones your area falls under and what plants you need to put in each year. Planting Zones in the United States, Organized by State

You may find your individual plant hardiness zone by entering your zip code on the USDA website. There may be only one or two principal growth zones in some states, such as the smaller northeastern states. In contrast, larger states like as Texas and California may have a wider variety of growth zones. According to the USDA hardiness zone, Texas has zones 6 through 9a, while California has zones 5a through 11a.

View these examples:

  • Temperatures in Zone 1 fall between -60° and -50° F.
  • Minus -50° to -40° F is the average temperature in Zone 2.
  • A minimum average temperature of -40° to -30° F is required for Zone 3.
  • A typical low temperature in Zone 4 is between -30°F and -20°F.
  • A minimum average temperature of -20° to -10° F is required for this zone
  • Minimum average temperature of -10° F or lower is required for Zone 6.
  • Zone 7: An average temperature of 0 to 10 degrees Fahrenheit.
  • Zone 8: temperatures range from 10 to 20 degrees Fahrenheit on a daily average.
  • At least 20° to 30° F is the minimum average temperature in Zone 9.
  • Temperatures in Zone 10 range from 30° to 40° F on average.
  • Minimum temperatures in Zone 11 range from 40 to 50 degrees Fahrenheit.
  • Minimum average temperature of between 50 and 60 degrees Fahrenheit is required for Zone 12.
  • Minimum average temperature of 60 to 70 degrees Fahrenheit in Zone 13.

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Planting Zones by Province in Canada

Provinces in Canada can have dramatically varying planting zones based on their size, just like states in the United States. It’s critical to know your local plant hardiness zone. This map of Alberta or this map of planting zones in Canada may help you choose which zones are most suited to your location.

North America’s horticultural regions include:

  • Zone zero
  • This is the first zone on the map.
  • This is Zone 2.
  • Zone three
  • This area is designated as Zone 4.
  • Zone 5 is where you want to be.
  • In the sixth arrondissement
  • Zone 7 of the electromagnetic spectrum
  • Zone 8 of the United States

Can a Greenhouse Help Extend Your Growing Season?

Whatever your needs, a greenhouse may be the appropriate option for you.

  • having problems with plants that need cooler temps to thrive because you reside in an area where you can plant all year round.
  • Because of the frigid winters in your area, you need aid safeguarding the veggies and flowers you want to cultivate from the harsh weather.

It is possible to manage the amount of heat or cold your plants receive, as well as the amount of sunlight and water they receive, by using the greenhouses provided by Planta.

For individuals living in mountainous, snowy, and windy areas or those at high elevations, a greenhouse may be the best option. More elements affecting plant growth can be controlled in a greenhouse, and more sensitive plants can be protected from harm.

Find out how our greenhouse solutions may help you make the most of your garden by contacting us today!

January Garden Planning

Gardeners have the opportunity to set fresh objectives and aims for the new year in January. It’s an exhilarating period of time, with countless opportunities at hand. It’s a month when you may take it easy and relax, so take advantage of the slower pace and lesser demands to congratulate yourself for your accomplishments from the previous year and to fantasize about the year ahead.

Review of Last Year

One of the most important things to do is to reflect on the achievements and failures of your garden in the past. A better gardener is one who practices what they preach. As you work to resolve issues that have arisen, remember the good things you did in previous years and the mistakes you made.

If you haven’t started a gardening notebook yet, do it right now! The logbook is a great place to keep track of the plants you already have, as well as the ones you’d like to acquire.

It’s the perfect time of year to doodle and arrange your garden’s layout. If you want the most productive garden, consider crop rotation, companion planting, and succession planting. Chart the seed and plant kinds in a designated area of the garden. Making sure you have all the information you need for future plantings at hand will be a lifesaver. Knowing when to sow seeds, plant with appropriate spacing, expect flowers, and harvest your plantings can help you stay on track year after year.

Garden Planning

The colorful seed catalogs that arrive around this time of year are much anticipated by many people. The seed catalogs that have been flooding your mailbox since the beginning of the year are at their busiest in January. Make yourself a cup of tea or hot cocoa and peruse these pages to get your creative juices flowing as you plan your next garden. Order your seeds early to avoid missing out on the best variety before they’re all gone.

If you order climbing veggies, fruit, or decorative seed kinds, be aware that they will need some kind of support structure to grow properly. Climbing structures and DIY trellises can be built indoors during the slower-paced month of January. It’s only a matter of time before we see the first signs of spring in the garden. Vertical gardening is a great way to save space in your garden beds, but you’ll need the correct equipment to get started sooner and avoid having to worry about bent stems!

Spring Garden Planning Zone 6

Zone 6b urban organic gardener Resh Gala demonstrates some of her favorite garden design approaches in this video. When it comes to gardening, no matter how big or tiny your space, the Kellogg Garden Youtube Channel has a video that will help you maximize your space.

Garden Maintenance

Pruning fruit and non-flowering ornamental trees, deciduous vines, rose bushes, and grapes in Zones 6-8 is best done in the month of January. Pruning spring-flowering trees and shrubs should be postponed until after their early spring bloom.

Take a look at the mulch layer in your garden when the snow has melted. How much cover do the bulb beds still have? Increase the amount of mulch around perennials as necessary to keep them warm and to prevent soil erosion. When the snow thaws, mulch will help keep water from accumulating in your beds, saving them from damage.

Garden Tools

January is a good time to inventory all of your garden tools and find new homes for any presents you’ve received as well as tools you’d like to add to your collection. Once the planting season approaches, you’ll be glad you did.

Tune up, clean, sterilize, sharpen, and lubricate all of your tools to make sure they’re in good working order. With these tips, you’ll be well on your way to a successful gardening season. In addition, you must ensure that your garden is free of any diseases that may have infected it last season.

  1. To begin, clean your garden tools with steel wool or a metal grill brush.
  2. Wipe off the surfaces with a moist towel.
  3. Scuff away any rust spots on metal surfaces with coarse sandpaper.
  4. Wipe metal surfaces with a rag dipped in vegetable oil.
  5. Wooden handles with rough or splintering places can be smoothed off with a piece of sandpaper.
  6. Use a linseed oil-soaked rag to clean hardwood handles.

Planting seeds is a great way to get a head start on your gardening season. Zones 6-8 are great for seed germination, so stock up on everything you’ll need before you get started. Clean and tidy your seed starting supplies before you begin. Seed starting mix, grow trays, grow lights, and warming mats are all essential. Make a list of what you have and what you’d like to get, then organize your seed packs accordingly.

Outdoor planting season for the coming spring will be here before you realize it, which is a great deal of fun. Consider stocking up on row covers and hoop houses, which will provide additional protection and lengthen your growing season in these zones, where temperatures can drop below freezing at night.

Composting in Winter

Composting is an excellent way to improve the health of your plants. The foundation of a thriving garden is nutrient-rich soil. If you’ve already begun a compost pile, keep it fed with kitchen scraps, pine needles, and fully cooled wood ash throughout the month of January.

Indoor Planting and Growing

For those seeds that take a long time to germinate and mature, now is the perfect time to get a head start on indoor seed starting. To enjoy a winter crop indoors, sow seeds in an indoor planter and place them near a window in an area that gets plenty of sun.

Seeds of the following can be started in Zone 6:

  • Cauliflower
  • Cabbage
  • Leeks
  • Onions
  • It’s Dusty Miller’s birthday today.
  • Snapdragon
  • Geraniums
  • Begonias
  • Pansies
  • Delphiniums

Begin germination of the following in zones 7 and 8

  • Broccoli
  • Cauliflower
  • Cabbage
  • Lettuce
  • Kale
  • Onions

Many cool-weather crops, such as the following, can be transplanted or sown in Zones 7 and 8.

  • Broccoli
  • Spinach
  • Asparagus
  • Lettuces
  • Strawberries
  • Fennel
  • Carrots
  • Arugula
  • Beets
  • Spinach
  • Peas
  • Turnips

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Forcing bulbs indoors can be a lot of fun if you’re missing your garden during winter. Choose fast-blooming bulbs like amaryllis and narcissus to delight in their colorful displays and heady scents.

Greenhouse Gardening and Cold-Frames

Greenhouses and cold frames in Zones 6-8 can shield plants from the elements and lengthen the growth season. You may have been able to collect a lot more food this winter than you would have otherwise been able to, thanks to these helpful gadgets. During the winter months, root crops and greens perform well in greenhouses.

In Zones 7 and 8, some of the finest performers are:

  • Arugulas
  • Beets
  • Chard, Swiss
  • Greens with a hint of mustard.
  • Cauliflower
  • Radishes
  • Spinach
  • Broccoli
  • Carrots
  • Cabbage
  • Peas
  • Turnips
  • Lettuces

Look for winter garden vegetables that are cold-tolerant and have a shorter maturity period when you’re seed buying. Plants need more time to mature in the fall and winter because of the fewer days and lower temperatures.

Winter Garden Harvest

Gardeners in Zones 7 and 8 may look forward to a steady supply of produce all year long, while those in Zone 6 may have to experiment to find out what works best for them. Leafy greens can be harvested using the cut and come again approach and root vegetables can be harvested as needed throughout the month of January. As long as the soil isn’t frozen, root vegetables like carrots can be harvested over a long period of time, even after they’ve matured.

Winter temperatures inside a passive greenhouse

I acquired a low-cost temperature data logger to monitor the greenhouse’s temperatures. When transporting food, chemicals, or pharmaceuticals, these USB data loggers (affiliate link) are commonly used to monitor their temperature. Temperatures were recorded every 15 minutes and I left it running all year round.

This hoop house is the best at collecting the sun’s rays. Every time the sun comes out, the greenhouse temperature rises significantly. 60-70° F is possible even in the greenhouse on days when the temperature outside is below zero.

When it’s cold outside, the greenhouse plastic’s R-value of roughly 0.8 isn’t strong enough to retain the heat in. Almost immediately, the temperature drops to match the temperature outdoors. As a result, greenhouse heating is prohibitively expensive (my neighbor spends more than $1,000 a year to keep his at 50°F).

On the basis of the available information, it appears that a greenhouse would be a dangerous place to be, with extreme temperature changes. I was astonished by how well the plants fared in that environment.

The in the fall, the greenhouse extended our growing season by about 2 months

The humidity in the air drops as the fall weather cools down, but it’s a very different story in the greenhouse. When the sun begins to heat things up, water evaporates and the air becomes extremely humid. My glasses always get fogged up as soon as I step foot inside. The water vapor has nowhere else to go, so it condenses on the plastic and rains back into the greenhouse.

This humid terrarium setting appears to be ideal for sensitive leafy leaves. A hot day will cause my plants to quickly die if I open up the vents on the side of my house.

Even though the plants outside were starting to die, the greenhouse was producing some of my most lush greens ever. The good times were about to come to an end, though, when we had a good frost…

Early in November, there was a strong frost. A low of 21°F was recorded overnight in the greenhouse’s thermometer. Everything was frozen solid and covered in ice crystals when I went to check on the plants in the morning. Ice glistened on the lettuce leaves, becoming them translucent. As soon as I got home, I called my wife and let her know that our greenhouse experiment was officially ended for the year.

Later, when the sun began to rise, the temperature began to rise as well. Astonishingly, most of my plants had totally recovered by the time I walked outside to clean up the mess. I knew lettuce was hardy, but I didn’t know it could withstand temperatures as low as minus 30 degrees. As if it wasn’t bad enough, the garden outside was practically devoid of life.

Aside from the kale and the lettuce, my other vegetables were all in good shape at this stage. Beets were the only ones that didn’t make it into the greenhouse. A few weeks later, when the greenhouse dropped to 13°F, most of those plants were still alive.

After the exterior garden was finished, the greenhouse crops continued to come in for another two months. The plants froze at night then thawed again in the morning with the rising sun, continuing to grow. It’s hard to believe that it’s already December and I’m still harvesting greens and root vegetables.

In the spring, the greenhouse growing season started 2 months early

Some lettuce, tatsoi, and tarragon seedlings were sown in the first few weeks of March. At the time, it was about two months before I usually begin my outdoor gardening program. The seedlings had a sluggish beginning. After a frosty night, the plants would thaw out to continue growing as the sun came out. The plants grew quickly as the weather warmed up, and by the middle of April, I was able to select my own fresh greens once more.

Because lettuce grows so quickly in the greenhouse, I didn’t stop planting after one round this spring; instead, I planted every few weeks. All in all, I think I grew four separate lettuce crops and six rounds of arugula. In my greenhouse experiments, arugula has been the fastest-growing crop I’ve attempted. Four weeks after I plant the seeds, I can start harvesting.

The greenhouse was a big success in extending the spring and fall growth seasons, but I also used it in the summer. I started planting some early tomatoes and cucumbers when the nights started getting a little longer.

During the summer months, the greenhouse made some crops more productive

In the greenhouse, the tomatoes and cucumbers began producing fruit considerably earlier than in the garden. Cucumbers went crazy in the greenhouse as I was overcrowding the plants. These plants thrived in the increased heat, and I’ve never had such good luck with them in the past.

Even during the hottest months of the year, all of my plants grew larger and more lush in the greenhouse.

Midway through July, I found myself drowning in cucumbers and early tomato plants.

However, my outside garden yielded more fruitful tomatoes from larger kinds than smaller ones. There are two possibilities here: either my greenhouse is somewhat shaded during the summer, or I watered the plants incorrectly. No matter what happens next year, I think I’ll just grow smaller cherry tomato varieties in the greenhouse and leave the larger variety in the garden.

How this hoop house design held up with snow

I was concerned about snow load when I erected this greenhouse. Hoop houses have collapsed after heavy storms in New England, where snowfall is common. As a result, I erected a beam down the middle of the greenhouse to increase its stability. It’s been flawless thus far.

When our winter storms were at their worst last year, I was in Costa Rica surfing in the worst days. Despite the fact that there was no one to clean the snow, the greenhouse was OK. The mild winter we had last year means I won’t declare it completely snowproof until we get a few major blizzards.

Overall, I haven’t had to undertake any structural repairs. The wiggle wire (affiliate links) I used to secure the 6 mil plastic to the framework has performed flawlessly. When it was hot outside, I’d open the side vents and the greenhouse stayed comfortably cool.

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Despite the fact that I wouldn’t alter the original design, I’ll make a few minor changes to the configuration. Automated watering with soaker hoses, as I have in the garden, is something I’m considering. The side vents, even when partially open, can flap in severe gusts and should be securely secured. To save myself the trouble of having to do it by hand, I’m thinking about including an automated venting feature.

Additionally, greenhouses provide other benefits.

The greenhouse not only extends our growing season, but it’s also a great place to relax. Even when it’s raining outside, I can still work in the greenhouse and keep dry and comfortable. The majority of our weeding takes place in the evenings while we’re having a few beers in the garden. Our greenhouse garden may now be enjoyed at any time of day or night, even as the days get shorter in the fall.

I also have less pests to deal with because the entire space is enclosed. Because I use chicken wire on the sides, even when the side vents are open in the summer, the space is shielded from the elements. But birds, squirrels and chipmunks have been kept out of my yard.

Another advantage of keeping plants indoors is how clean they stay. Greens picked from the greenhouse require little to no cleaning because of the absence of wind and rain. With all the greens we’re getting, this saves a lot of time.

Overall, the greenhouse extended our growing season by over 60%

Our typical gardening season runs from May through October. It had around a 10-month growing season in the greenhouse, from March to December. An incredible 67% rise!

Last year, I didn’t sure what to anticipate when I built this greenhouse for our urban homestead, but it has turned out to be just what we were looking for. It’s been a terrific addition to the property, and the plants have thrived there compared to the garden. This year’s harvest has beyond my expectations, and the greenhouse has made me appear to be a greater gardener than I am.


Most crops and plants may be grown successfully in a greenhouse, freeing you from the restrictions and drawbacks that come with gardening in the open air. To begin planting, you must first determine your greenhouse’s hardiness zone. Your state’s or region’s growth and planting zone influences the average annual extreme low temperature.

Once you’ve gathered this data, you’ll be able to make informed decisions on plants, greenhouse settings, and equipment. Keep in mind that temperature fluctuations, exposure to sunlight and other forms of environmental stress, soil quality and the health of the plants are all important considerations. These characteristics are distinct from the hardiness zone and may only apply to your garden.