Blueberries, which strangely aren’t always blue, are one of the easiest fruits to grow. If you have the right acidic soil conditions and plant them at the right time, you’re on the right track.
Our 2021 planting guide has lots of tips and advice to make sure your blueberries thrive.
When to plant blueberries? Unless you live in a very cold region, you can plant them in spring and late fall. If you live in Zone 5 or a lower zone, it’s generally better to plant in the first half of spring. If you are growing them from seed, use starter trays, and plant them in late winter or early spring.
Planting Blueberries in Different Climates
Blueberries are one of the only fruits that are native to North America.
But, as The National Gardening Association sagely says, gardeners need to compare the climate in their home garden with the climate in which plants grow well.
If it isn’t going to tolerate the year-round conditions in your area, it’s best to grow your plants in a greenhouse or choose something else to grow.
Important factors to take into consideration are rainfall and both high and low temperatures. You can always amend the soil to make it suitable for blueberry growing, but you’ll be at the mercy of local weather conditions.
You will often find that seed packs and many websites provide information about which United States Department of Agriculture (USDA) hardiness zones plants do best in. These are gardening zones.
If you don’t know which zone you fit into, it is easy enough to find out. For instance, The National Gardening Association and other resources publish USDA hardiness zone maps and/or have search capabilities that will help you check.
There are four different types of blueberries, highbush being the most common. You will find that different varieties of highbush are suitable for different cold hardiness zones, so choose the best for your hardiness zone.
The other way to assess, very simply, whether certain plants, including blueberries, will succeed in your garden, is to recognize your climate.
Since plants grow best in the climatic conditions found in their native ecosystem, it isn’t rocket science to realize that climate zones can be very useful for gardening.
Different Climate Types
The basic types of climate in the world were defined by a German climate scientist, Wladimir Köppen, at the turn of the twentieth century. He based his categories on rainfall and temperature, including the times of the year when rain was recorded.
He was a botanist, and so also based his system on the types of vegetation that grow in each region.
There are five main climate groups in the Koöpen classifications. Each of these groups is subdivided with reference to rain and heat.
If you know the climate of your region, you will know what weather conditions are experienced. This, like the gardening zones, will help you to determine which plants, and varieties of plants, are likely to grow best in your garden.
Of course, like most things in life, climate categories aren’t that simple, and some U.S. states experience multiple different climates in different parts.
It can be mind-boggling! But let’s have a quick look at the five basic Koppen climate categories.
It’s hot and humid in the tropics. Average temperatures are typically more than 64°F or 18°C and there is more than 59 inches or 150 cm of rain every year.
The important factor here is rainfall. It’s dry because the moisture in the air evaporates quickly, minimizing the possibility of rain.
Hot desert, cold desert, hot semi-arid, and cold semi-arid regions are all categorized as dry-climate regions.
Winters are mild and summers are typically warm and humid, often with thunderstorms.
There are many subdivisions in this climate category. They include humid subtropical and other subtropical climates, as well as oceanic and Mediterranean climates.
There’s a bit of a difference between summer and winter, with summers being warm but sometimes cool, and winters very cold.
At least one-month averages below 32°F or 0°C and another above 50°F or 10°C. Winter temperature can fall below -22°F or -30°C.
There are regions with a humid continental climate, a subarctic climate, and even Mediterranean-influenced climates.
For gardeners, this is greenhouse territory. It gets extremely cold, and even in summer, you won’t experience temperatures that are higher than 50°F or 10°C!
Choosing Blueberries Seeds
There are four different types of blueberries, lowbush, highbush, rabbit eye, and hybrid half-high. But the most common type is the highbush, which comes in two forms, the northern and southern highbush, both of which are grown commercially.
The northern highbush thrive where winters are cold, specifically in USDA plant hardiness zones 4-7. Southern highbush blueberries prefer warmer weather and will do especially well in a Mediterranean climate.
There are also different blueberry varieties, including pink blueberries like Pink Lemonade and Pink Champagne.
As the U.S. Highbush Blueberry Council points out, both climate and the ripening season for different blueberry varieties must be taken into account. Even though they are all classified as highbush blueberries, the various varieties have their own shape, size, color, taste, and season.
You can buy blueberry seeds online from Amazon, an American seed and plant company like Burpee, or other distributors. Or you can buy seeds from local garden centers and other high-street shops that stock them.
The blueberry seeds you choose to plant should be suited to your region.
Different Blueberry Varieties
The choice of blueberry varieties is staggering.
A Cornell University College of Agriculture and Life Sciences Cornell Cooperative Extension Blue Variety Review lists 24 varieties according to three seasonal categories:
- Early season
- Late season
So, there’s lots of scope in terms of when you can plant blueberries. Most varieties on their list are winter-hardy to -25°C, which means they will thrive in a continental climate.
Additionally, many institutions undertake ongoing research that results in new blueberry varieties. For example, Washington State University is currently involved in a $12.8 million research project that aims to make new, tastier blueberries.
Sizes & Types of Blueberries
When you plant blueberries, you aren’t limited to seeds. Nursery plants are available in different forms:
- In containers
- Bare root
- Tissue culture
They are also available in different sizes:
- Plugs from tissue culture
- Two- to three-year-old potted plants
- Rooted cuttings
It stands to reason that the larger the plant, the sooner it will mature and produce fruit.
How to Plant Blueberries Seeds
Growing blueberries from seed is a long process that takes years.
Blueberry seeds take at least a month, sometimes two to three months, to germinate. Then you need to let the seedlings establish themselves and allow the plants to grow.
A good rule of thumb is to plant seeds inside in early spring or later winter. They will, though, germinate at any time as long as they get enough warmth and light.
Plant your seeds in sphagnum peat moss or a premium quality concentrated seed-starting mix. The seed trays or flats you use should be about three inches (7-8 cm) deep to allow the roots to develop.
Sprinkle the seeds on the peat moss and cover very lightly. Keep them in a warm place where there is bright light, and keep the peat moss moist while the seeds germinate.
Then you need to let the seedlings grow until they are two to three inches (5-8 cm) tall. Transplant into pots and feed with a weak acid liquid fertilizer.
When they are about 8 inches (20 cm) tall, transplant into bigger one-gallon (3-4 liter) pots.
They will be ready to plant outside in prepared beds in one or two years.
During the first year, your blueberries might not grow more than five or six inches (13-15 cm). They won’t bear fruit until they are about one to two feet tall (31-61 cm), usually when they are about two years old.
How to Water Blueberries
Blueberries are shallow-rooted and need more water than other fruits.
While they are growing in seed trays, keep the peat moss moist but not wet. Water well while they are growing in pots, but don’t over-water.
Once you have planted them out, focus on deep watering rather than keeping the surface of the soil moist. As a guide, make sure your blueberry plants get about an inch (2.5 cm) of water every week during the growing season.
How to Grow Blueberries
When your seedlings are ready to plant outside, you need to be sure you have a suitable site for them.
It should be a sunny but sheltered spot that gets full sun for at least three-quarters of the day. Blueberries don’t mind partial shade but avoid sites where trees will block out the sunlight.
You also need to check and possibly amend the soil.
How to Amend the Soil for Blueberries
Blueberries are acid-loving plants and prefer acidic soil with a pH between 4.0 and 5.0. Get yourself a soil testing kit to make sure that it is acidic enough.
If it isn’t, you can make the soil more acidic by mixing in a little granulated sulfur a few months before you plant your blueberry seeds. Peat moss, and pine needles and bark, will also help to make the soil more acidic.
Because blueberries are shallow-rooted, they need to be planted in soil that drains well but holds sufficient moisture for growth.
If you are going to plant blueberry bushes, mix organic matter into the soil. This will help the bushes to set.
How to Plant Blueberry Bushes
Whether you have grown your blueberry plants from seed or bought blueberry bushes, you can plant blueberries in the fall or spring. Just make sure there is no danger of frost.
You can plant blueberry bushes quite close together – only about two feet (30-31 cm) apart if you want to create a solid hedgerow. Otherwise, space them about six feet (1.8 m) apart and leave eight to ten feet (2.5 to 3 m) between rows.
They grow particularly well in raised beds.
Dig planting holes that are about 20 inches (51 cm) deep and 18 inches (20 cm) wide. It should be about twice as wide and deep as the roots of the plant.
Backfill planting holes with a rich organic compost mix and pack tightly around the base with soil.
Blueberries also benefit from two or three inches (5-10 cm) of mulch to keep the moisture in. You can use straw, sawdust, or pine needles.
Presuming you decided to plant blueberries in the fall, you should fertilize them in early spring when you see that the plants are no longer dormant. A well-balanced 10-5-5 fertilizer is a safe bet.
You don’t need to prune your plants until they are at least three years old and have produced berries. Only remove the oldest branches.
How long do Blueberries take to grow?
Growing blueberries from seed takes a lot longer than growing them from bare root or seedlings. It commonly takes about two years before the plants are ready to plant out in garden beds.
They will obviously grow more quickly if you buy two- to three-year-old plants in pots that can be planted directly into garden beds.
Blueberries are native to North America and they aren’t difficult to grow. They are, though, slow to germinate, and won’t bear fruit until they are two or three years old.
But blueberries are a worthwhile addition to the home garden and they continue to produce fruit for decades.
Our planting guide tells you how and when to plant different types of blueberries. Whether you want advice on where to plant, what to plant, and when to plant blueberries, you will find invaluable information right here.