Thinking about starting a garden or adding new plants to your yard this year? This guide will provide you with information about planting zones and the length of your growing season. Anyone can have success gardening. Knowing these two pieces of information can help you to be successful in your gardening journey.
If you are looking to grow a vegetable garden or an annual flower garden it is important to figure out the start date and end date of your growing season. This information will help you determine when frost tender plants can be put outside without protection from freezing temperatures. This length of time is called your growing season.
How to Calculate Your Growing Season
- Find out your average last frost date
- Determine your average first frost date
- Count the number of days between those two dates
- That number will be your average growing season
- The average dates are based on data collected each year
Your First and Last Frost
With a quick Google search you can find out your last and first average frost dates. I used this link from the Farmer’s Almanac . The Farmer’s Almanac uses data provided from NOAA the National Oceanic Atmospheric Association to calculate dates.
Dave’s Garden website also provides information about your specific zone based on your zip code. The site includes data from surrounding towns. Another useful tool is a table showing how likely your area is to receive freezing temperatures before or after the average frost dates. For example, for where I live there is a 50% chance that I will experience a frost up until May 20th and only a 10% chance of getting a frost as late as June 6th.
Guidelines Not Set Rules
Remember the weather is unpredictable and some years are just colder than others. Your specific location within your zip code can also have an impact on your weather. I live in a spot in town that is pretty high in elevation. This rise in elevation means I usually receive snow when other areas below me get rain. When driving to my house I often cross a snow rain line at the same location.
Your local garden center can provide more information that is specific to your area. They can be a great source for information since they are typically living around where you live.
Warm Pockets in Your Yard
Last year after our first frost, I noticed that some areas of my garden still had annuals that seemed to be unaffected by the dip in temperature. This phenomena can be caused by different temperature pockets or zones in your own yard. One of my gardens is placed in a more protected area where the ground dips down low near the tree line. This is where I noticed the untouched zinnias and petunias continuing to grow.
However, my other garden is placed on a slope in the wide open with no protection from the wind and sun. In this area, most of my annuals were killed from that first frost. I did have cosmos that hung on for a little while longer, but I’m not sure what caused them to be unaffected. I’m thinking that the variety I grew was a more hardy version.
Is a Growing Zone the Same as a Growing Season?
No, both are useful pieces of information for the gardener, but they are not the same. A growing zone formally called a Plant Hardiness Zone is based on the average low winter temperature of an area. For example, living in zone 5, I can expect my lowest annual winter temperature to be -15 OF( -26 OC).
What Zone Am I?
- Look at a Plant Hardiness Zone Map
- Find your location
- Use the Key to match your location’s color with the appropriate zone
- Zones can be further broken down into subzones (Zone 5 can be 5a or 5b).
I don’t typically pay attention to the sub zone, but it is helpful information to know. For more information about planting zones and to determine which zone you are in visit the United States Department of Agriculture website. On their website, you can click on your state, if you live in the US and it will bring you to a zoomed in version. Using that zoomed in map you can see which zone, along with any sub zones, your area falls under.
Same Zone Different Growing Season
Gardeners who share the same growing zone may have growing seasons of different lengths. For example, I love watching Laura from Garden Answer’s YouTube channel where she shares what it is like growing in Zone 5. She lives in a high desert climate. In New England, we have a humid continental climate. I’m not sure if our climates are the reason, but she has a longer growing season than I do.
So while daffodils and tulips are bursting into bloom in her yard, mine are barely peeking out from under the snow. We live in the same zone, but I will have to wait another 3-4 weeks for mine to start blooming. For more information you can view Garden Answer’s US Plant Zone video where Laura explains climate zones.
I will also have to wait to set out my annuals if there is still a danger of frost. Gardeners living in your same zone, but who live in different states and climates can provide you with a wealth of knowledge. You just have to pay attention to the the start of your growing season to make sure you are not putting out plants too early.
Why is Knowing Your Zone Helpful?
Knowing your growing zone can help you determine if a perennial will survive in your area over the winter. Day lilies, roses, and trees are all examples of perennials. For a plant to grow and thrive in your climate, research or check the tag when purchasing to see if that plant is suitable for your zone. Every plant will have a growing range where it will perform best because it is living in its ideal conditions. Some plants do not grow well in warmer climates. The lack of cold can cause a plant to suffer because it is growing in an area that is too warm in the winter.
Protecting Frost Tender Annuals
Many gardeners start seeds indoors or inside greenhouses while there is still a chance of frost outside. We do this to give plants a head start on the growing season. Many vegetables require a long growing season to grow, set flower, then create a fruit which can be harvested. Vegetables such as tomatoes require heat in order to thrive in the garden. If I tried planting tomatoes outside after my last annual frost date, they would struggle because the daytime and nighttime temps have not warmed up enough.
To off set the cold weather you can purchase plant starts from a local garden center or farmer. You can also start your own seeds indoors in a sunny window or under grow lights. Once the weather has warmed up, you can plant them outside. They will then have enough time to complete one whole life cycle before the frost returns.
Covering Plants Outside
If you happen to plant annuals and you experience an unexpected late season or early season frost you can still protect your plants. You can move small potted plants into the house or a shed for the night. If they are too heavy to move or planted in the ground, you can drape a sheet over the plants to protect them from frost damage. I have even covered my plants using an upside down plastic container.
If there is one season where I really play close attention to the night time and day time temperatures, it is spring. I would hate to loose plants that I started indoors weeks prior or spent good money on just to have them die due to the cold.
This year I am starting seeds in mini hoop houses that I build last fall that go over my raised beds. PVC makes up the frame of the hoops. On top of the hoops I secured green house plastic. The plastic will help to trap warm air during the day. Also keeping nighttime temperatures warmer than they would be if I planted without cover. Gardening with James Prigioni’s on YouTube goes over step by step directions for building similar hoop houses. I build mine using a combination of his directions and other information found online as my guide.
Tour Local Gardens
When first starting a garden it can be helpful to tour local gardens including gardens at your friends and neighbor’s houses. Gardener’s are often eager to pass along cuttings and divisions from plants growing in their yard. If the plant is a perennial that has survived the winter in their yard, and you live close by chances are it will also survive in yours.
Locals can provide you with growing tips and inspiration. I absolutely love viewing other people’s gardens and seeing what plant combinations they have come up with. Sharing a swapping plants is a great way to build community and form relationships with your neighbors.
Learn Through Experience
Don’t let all of the data and rules surrounding planting zones and growing seasons stop you from trying out something new. Most of what I have learned as been through trial and error. I have killed my fair share of plants, but I also have been able to create gardens filled with happy thriving ones.
This year, I am going to attempt to grow a large vegetable garden. If I’m being honest I’m nervous and intimidated by the whole process. All of the planting information for different plants can be overwhelming even for an experienced gardener.
I have years of experience growing perennials and annual flowers, but only some practice growing vegetables. When I look back five years from now, I will have gained so much knowledge and confidence just from trying it out myself.