Ohio Growing Zones Explained

Ohio Growing Zones Explained

If you are planning to start a garden in Ohio, you need to learn about the growing zones in the state to determine what plants will grow best in your area. Years ago, the USDA established a nationwide system for classifying climatic conditions in the United States.

Each state has a different growing zone map, and each map uses a different base temperature as its guideline. These areas are called “plant hardiness zones.” With this system, landscape planners can decide which plants are most likely to thrive in each region. In this article, we will discuss the various growing zones in Ohio and provide you with the necessary information to have a thriving garden.

How to Know Your Growing Zone in Ohio

To find your gardening zone, visit the United States Department of Agriculture  (USDA’s) website. While there, you can either enter your ZIP code or use the interactive map to zoom in on the street you live in. Alternatively, you can use the USDA plant hardiness zone map to locate your Ohio growing zone.  To find your growing zone, you have to look at a map and locate where you live. Once you find that, you will need to match the color of your location to the legend on the right.

Growing Zones in Ohio

The state of Ohio is an agricultural powerhouse with 13,600,000 acres under cultivation by 2020. In Ohio, the winter temperatures fall in the range from 0 to -20 degrees Fahrenheit. It is divided into three different zones: 5b, 6a, and 6b.

Depending on where you are in the state, the zone might change. Large parts of the Northeast are Zone 5B, including much of Lake County and Ashtabula County. Parts of the northwest are Zone 6A, including Montgomery County, Union County, and Miami County.

Ohio’s Growing Zone 5b

Northern Ohio has a cold climate with an annual minimum of -10 to -15 degrees F. It is in zone 5b on the USDA scale. The last frost can happen from March 30 to April 30, and the season’s first frost usually happens in October. Long-season plants such as watermelons, tomatoes, and winter squash should be started indoors to have a good chance of growing in the colder climate.

Plants That Do Well in Ohio’s Zone 5b

It is essential to do the necessary research before planting a garden. Plants need a lot of time and space, and you don’t want to make a big mistake by planting something in the wrong place at the wrong time. You can grow various plants like vegetables, shrubs, perennials, annuals, fruit trees, etc. 

Vegetables to Grow in Ohio’s Zone 5b and When to Plant Them 

If you are planning on growing vegetables, the first thing is to determine what temperature range your plant needs to grow in. The last frost of spring is usually between mid-April and late May. Make sure you note these dates to avoid having your crop overwhelmed by the extreme cold or frost.

The best thing is to wait until the midnight temperature is significantly higher than 32°F. But if you have to plant, consider going for vegetable varieties that thrive in cool weather, such as broccoli, cauliflower, or turnips. Below are some of the vegetables that do well in this zone.

  • Kale
  • Kohlrabi
  • Lettuce
  • Mustard
  • Peas
  • Potatoes
  • Radishes
  • Cauliflower
  • Chicory
  • Beets
  • Brussels sprouts
  • Rhubarb
  • Asparagus
  • Cabbage
  • Broccoli
  • Carrots
  • Cress
  • Peas
  • Potatoes
  • Radishes
  • Rhubarb
  • Salsify
  • Spinach
  • Swiss chard
  • Turnips
  • Muskmelon
  • Watermelon
  • Pepper
  • Pumpkin
  • Rutabaga

Perennials to Grow in Ohio’s Zone 5b and When to Plant Them

In the spring, we look forward to seeing flowers from perennials in our garden. Growing hardy perennials that can withstand the winters in zone 5 adds to the beauty they bring to our gardens.

Although spring is the best time to plant, you can grow your perennials in the period between the last frost and a few weeks before the onset of the first fall frost. Below are the types of perennials that you can grow in zone 5.

  • Echinacea
  • Bee balm
  • Phlox
  • Daylily
  • Delphinium
  • Rudbeckia
  • Filipendula
  • Sedum
  • Lilies
  • Lavender
  • Gaillardia
  • Poppy
  • Salvia
  • Penstemon
  • Russian sage
  • Hollyhock
  • Peony
  • Butterfly weed

Annuals to Plant in Ohio’s Zone 5b and When to Plant Them

To grow a successful crop of annuals, you need to note weather forecasts and frost warmings to protect your plants. Some annuals, such as pansies and snapdragons, do well in cold weather, and you can plant them in April. Other annuals mostly do well in warm conditions, and you can grow them from the end of May to avoid frost.  Annuals that thrive in Ohio’s zone 5 include;

  • Geraniums
  • Lantana
  • Petunia
  • Calibrachoa
  • Begonia
  • Alyssum
  • Bacopa 
  • Cosmos 
  • Gerbera Daisy 
  • Impatiens 
  • New Guinea Impatiens 
  • Marigold
  • Zinnia 
  • Dusty Miller 
  • Snapdragon
  • Gazania
  • Cleome
  • Four O’clock
  • Cockscomb
  • Torenia
  • Nasturtiums
  • Moss Roses
  • Sunflower
  • Coleus
  • Gladiolus

Tips For Farmers Growing in Ohio’s Zone 5b

  • If you want to start planting seeds instead of buying plants, May 30 is an excellent time to start your seeds outdoors.
  • The area enjoys lots of sunshine, which makes it perfect for growing perennials and annuals.
  • You can plant some vegetables late in the summer or early fall to prepare for harvest in winter. In this case, you will need to protect them with a covering mulch, cold frame, or cover crops.

Ohio’s Growing Zone 6

Zone 6a covers much of Ohio. Winters can be particularly harsh here, with temperatures dropping to -10 degrees Fahrenheit. Generally, plants designated for zones 6 through 9 are hardy enough to withstand the lower temperatures of southern Ohio winters but may not thrive in northern Ohio.

Plants Suitable For Ohio’s Zone 6a

Zone 6 is a moderate climate with a frost-free period from the middle of May to mid-September. Zone 6a has an average winter temperature of -10 to -5 Fahrenheit, making it a bit colder. There are a variety of vegetables, perennials, and annuals that you can grow in zone 6. 

Vegetables to Grow in Ohio’s Zone 6a and When to Grow Them

Zone 6 is the perfect place to produce all kinds of vegetables. You can plant your vegetables from mid-March to November. Planting at the wrong time can result in slow growth and sometimes even death of your plants. A mix of warm and cold weather plants is suited to the zone. Examples of vegetables to grow in this zone are;

  • Peas
  • Cauliflower
  • Tomato
  • Kale
  • Onions
  • Celery
  • Brussels sprouts
  • Cabbage
  • Spinach
  • Broccoli
  • Eggplant
  • Peppers
  • Cucumber
  • Radish

Perennials to Grow in Ohio’s Zone 6a and When to Grow Them

Horticulture is an integral part of both indoor and outdoor living. Whether planting your garden bed or working with a professional, picking the right plants for your area is essential. Ohio enjoys beautiful seasons, with scorching summers and freezing winters.

That means that it takes specific perennials to grow appropriately in different parts of this state. You can plant your perennials between late May and mid-October, right after the first frost. Below are some of the perennials that you can grow in your garden. 

  • Wild Lupine
  • Obedient Plant
  • Columbine
  • Blue Flag
  • Black-Eyed Susan
  • Gayfeather, or Blazing Star
  • Cardinal Flower
  • Blue False Indigo
  • Blue Vervain
  • Butterfly Weed
  • Cardinal Flower
  • Culver’s Root
  • Goldenrod
  • Great Blue Lobelia
  • Joe Pye Weed
  • Marsh Marigold
  • Obedient Plant
  • Ox-Eye Sunflower
  • Smooth Penstemon
  • Swamp Milkweed
  • Turtlehead
  • White Wood Aster
  • Wild Bergamont
  • Wild Geranium
  • Wood Poppy

Annuals to Grow in Ohio’s Zone 6a and When to Grow Them

When planting annuals, it is necessary to consider the plants’ hardiness and whether they are “cool-season” or “warm-season.” Cool-season annuals are hardier and can grow in cooler climates, while warm-season annuals require sunnier, warmer temperatures. Below is a list of annuals to choose from for your garden.

  • Calibrachoa
  • Cleome
  • Cockscomb
  • Cosmos
  • Angelonia
  • Bacopa
  • Begonia 
  • Four O’clock
  • Fuchsia
  • Geranium
  • Heliotrope
  • Impatiens
  • Lantana
  • Lobelia
  • Marigold
  • Pansy
  • Petunia
  • Snapdragons
  • Strawflower
  • Sunflower
  • Sweet Alyssum
  • Torenia
  • Verbena

Ohio’s Growing Zone 6b

There is a small area in the southwestern region of Ohio classified as 6b by the USDA. That means it is a colder climate that drops to -5 degrees Fahrenheit during the coldest part of the year. Luckily, because of the slightly warmer temperatures, the growing season may be longer. Fruits and vegetables have more time to ripen in this zone.

Vegetables That Do Well in Ohio’s Zone 6b

You might think Ohio is a terrible place for growing vegetables because of the cold winters, but you would be wrong. Ohio has an ideal growing season that allows many vegetables to grow, even in the winter months. March to November is a perfect time to plant your vegetables in this zone. Below are some vegetables that you can grow in your zone 6b garden.

  • Cabbage
  • Swiss chard
  • Arugula
  • Celery
  • Onions (Bulb)
  • Eggplants 
  • Beets
  • Carrots Spinach
  • Lettuce
  • Sweet potatoes
  • Turnips
  • Pumpkins
  • Mesclun mix
  • Cucumbers
  • Watermelons
  • Winter squash 
  • Radish 
  • Green peppers
  • Tomatoes
  • Potatoes
  • Okra
  • Summer squash
  • Green beans

Perennials to Grow in Ohio’s Zone 6b

Zone 6 is characterized by its mild climate and cold winters, where the average lowest temperature is between -10°F and 0°F. This zone has a wide variety of plants that can grow nicely in this kind of weather. You can plant your perennials after the last frost (mid-March) to November. Here are the best perennials for zone 6b.

  • Astilbe
  • Coreopsis
  • Rudbeckia
  • Liriope
  • Salvia sylvestris
  • Geranium
  • Lilies
  • Asclepias
  • Agastache
  • Hostas
  • Peonies
  • Phlox
  • Foxglove
  • Campanula
  • Delphinium
  • Heuchera
  • Coneflower
  • Iris
  • Hellebores
  • Asters

Annuals to Grow in Ohio’s Zone 6b

Annuals are so versatile and have a variety of shapes and colors to offer. Planting them in your garden will allow you to create fascinating combinations that will last all season long. You can use bright colors such as zinnias or Mexican sunflowers or choose from the subtler pastel shades, such as stock or lavatera. You can start planting your annuals crop from the end of May. Below is a list of some of the best performing annuals in zone 6b.

  • Cosmos
  • Four O’clock
  • Fuchsia
  • Geranium
  • Heliotrope
  • Impatiens
  • Lantana
  • Lobelia
  • Angelonia
  • Bacopa
  • Begonia
  • Calibrachoa
  • Cleome
  • Cockscomb
  • Sunflower
  • Sweet Alyssum
  • Torenia
  • Verbena
  • Marigold 
  • Mexican Heather 
  • Moss Rose 
  • Nasturtium 
  • Nemesia 
  • New Guinea Impatiens

Tips For Farmers Growing in Ohio’s Zone 6

  • Moderate the soil with mulch to make it perfect for your plantings
  • The Japanese beetle is an invasive species that can take a toll on your garden. Another insect you might see in the garden are the Emerald Borer which destroys fruit trees by hollowing out the insides of the tree
  • Improving soil fertility is essential because of Ohio’s rain. Most gardens need additional humus.

FAQs

Question: What is the best time of the day to plant my annuals in Ohio’s zone 6?

Answer: The best time to plant is on a cloudy day. That way, your new annuals won’t get sun stress while settling into their new home. You can also tackle planting in the evening, which gives plants enough time to recover from the day’s sunlight. If you are planting on a sunny day, it is crucial to protect tender seedlings. One option is to place a flat object such as cardboard or a bedding plant over the seedlings to create shade.

Question: What is the difference between Zone 6a and Zone 6b?

Answer: The average winter temperature in Zone 6a is -10 to -5 degrees Fahrenheit, while Zone 6b is -5 to 0 degrees Fahrenheit. All plant and seed packets list the zones that the particular plant is best suited for. This is usually the coldest possible temperature that the plant can survive. You need to note the recommended zone on the seed packet to choose the correct plants to grow in your area.

Question: What tropical plants can grow in Zone 6?

Answer: Hardy eucalyptus, rice paper plant, and Yucca rostrata are great plants for a zone 6 garden. They are excellent in places with cold weather but still have some similarities to the tropics. Mexican bamboo and crape myrtle are also excellent clumping bamboo varieties that thrive in zone 6.

Question: What is the lowest temperature can annuals withstand?

Answer: Some annuals are more delicate than others. For example, impatiens cannot survive a light frost. Half-hardy annual flowers can survive in colder weather, but they may have to be covered when the temperature drops below 35 degrees. Regardless of which type of annual you have, always protect your plants in cold weather. You can use a light sheet or blanket to cover them and keep them warm.

Conclusion 

If you are a gardener in Ohio, understanding your growing zone and its limitations is very important. After all, knowing what to grow and where to grow is the key to a successful garden. Knowing your Ohio growing zone and climate is an essential part of planning for your garden.

Your location will help you determine the appropriate veggies, shrubs, and flowers to grow in your garden. This can be especially helpful when choosing what to grow since some plants are not native to the state.

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