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The Osorno Blueberry

If you’re in the market for an excellent midseason variety that has ideal firmness, flavor, and yield, you should take a look at the Osorno Blueberry. These blueberries have been shown to maintain their firmness even in high heat conditions and are noteworthy for their balanced acid to sugar ratio.

Also, with the right amount of pruning, this variety is ideal for mechanical harvesting, and studies suggest that the Osorno has superior heat tolerance when compared to Draper.

Below, we take a look at the Osorno Blueberry in greater depth to see why so many northern growers are singing this blueberry’s praises.

Closeup of large, light blue blueberries similar to the Osorno Blueberry.

History of the Osorno Blueberry

In 2002, the Southwest Michigan Research and Extension Center, located in Benton Harbor, Michigan, flowers from Draper were cross-pollinated with pollen from Legacy. Soon, they germinated the seeds and grew them in a greenhouse for about a year before planting them. The Osorno Blueberry, then called MSU 67, was picked out of a group of 103 siblings by Jim Hancock in 2006. The Osorno belongs to the Vaccinium corymbosum family.

Some Osorno Blueberry characteristics worth mentioning include:

  • Vigorous upright growth that’s slightly spreading
  • Medium to large-sized fruit (slightly larger than Draper)
  • A bit sweeter blueberry flavor than Draper
  • Small scar
  • Firm
  • It does well in warmer climates, but not so well in extreme winter temperatures.

Osorno Blueberry / Fruit Characteristics

Let’s take a closer look at the Osorno Blueberry.

Chilling Level

The Osorno Blueberry is a mid-chill berry that requires 1,000 chilling hours annually.

Ripening Season

The Osorno Blueberry ripens around the same time as Bluecrop and Draper, during the midseason, which is late July to early August.

You can also consult our handy guide on the Minnetonka Orchard website that covers more detail concerning the right time to pick blueberries.

Person picking blueberries.

Fruit Qualities

  • Berry taste: sweet, well-balanced acidity
  • Average berry texture: Firm
  • Color: Violet Blue
  • Average pedicel scar size: 2.2 millimeters

Berry Size

  • Average berry Size: Medium to Large
  • Average berry height: 1.52 centimeters
  • Average berry width: 1.75 centimeters
  • Average berry weight:

Planting Zones

The Osorno Blueberry is a highbush variety, which means zones 4-6 are ideal for these plants.

Keep in mind that these plants do not adapt as well as Draper to colder winter conditions. They can tolerate warmer climates as far south as central-southern Texas.

Before planting, it’s always a good idea to check the USDA Hardiness Zones before adding a new crop to your orchard or garden. You can also find more handy tips on growing blueberries in our reference guide: “How to Grow Blueberries.”

Person planting a blueberry shrub in the garden.

Size and Spacing

The average size of a mature Osorno Blueberry plant is about 4.5 feet tall and 3.6 feet wide.

If you’re planting inground, you want to plant each bush at least 2 to 2.5 feet apart if you’re growing them in solid hedgerows or up to 6 feet apart if growing them individually. If growing in rows, allow for 10 feet between each row, depending on the type of equipment you’re using for mowing or cultivating.

Pollination

For the best results, you should always try to pair your blueberry bushes with at least two or three different varieties. For the Osorno blueberry, we recommend Bluecrop, Tophat, Duke, and Draper as good cross-pollinating plants.

Osorno Blueberry Bush Care

Once again, it’s important to remember that Osorno Blueberry plants do not produce well in extreme winter environments. Also, you should factor in the semi-spreading attributes of these plants when planning your planting scheme and maintenance schedule.

Clusters of ripe blueberries on a bush.

Fertilizer

Blueberry bushes require fertilizer that’s rich in nitrogen. Fertilizers with ammonium forms such as urea, cottonseed meal, ammonium sulfate, and sulfur-coated urea are good choices.

But, you want to avoid using fertilizers that have the nitrate form of nitrogen since this type is toxic to blueberry plants.

You should use fertilizer once during early spring and one more time in late spring. You can also use organic fertilizers like blood meal and cottonseed.

Soil

For highbush blueberry plants like Osorno, you want acidic soil that has a minimum pH level of 4.5 and no higher than 6.8.

Also, if possible, you should incorporate rich organic matter into your soil. One recommendation is using aged compost-enriched soil and mixing it into the top six inches of your native soil.

We also found that peat moss and pine fines are good to mix into your soil. You should use about a bale of peat moss and about four bags of pine fines for every ten blueberry plants.

Sunlight

You should ensure that your blueberry bushes receive as much sunlight and as little shade a possible.

With this in mind, try to avoid areas with trees as they not only block the sun, but tree roots also compete for nutrients (a competition your blueberry bushes won’t win since they have shallow roots). Trees can also cause specific diseases in blueberry bushes that hurt air circulation. And trees are usually home to birds, many of whom love feasting on blueberries.

You want to make sure your blueberry bushes get at least eight to ten hours of unfiltered, direct sunlight each day. Too much shade will impact your plant’s yield.

Watering

As we mentioned earlier, blueberry bushes have shallow root systems that develop slower than many other plants. Because of this, you’ll need to make sure you water them deeply and regularly to ensure they reach their maximum growth potential.

If you’re using a drip irrigation system, you’ll want to ensure the soil receives even moisture.

Person watering a blueberry shrub.

Pruning

We recommend an annual pruning of your blueberry bushes. You may even need to prune more than once a year for Osorno, considering their slightly-spreading growth behavior.

Pruning encourages the growth of new berry-producing stems while allowing your plants to spend more energy on fruit than on its leaves. Pruning can have a considerable impact on the taste and quality of your fruit.

To learn more about the best practices for pruning blueberry bushes, take a look at our handy guide, “How to Prune Blueberries.”

Diseases & Care

You can learn more about diseases can harm your blueberry crop and how to deal with them in our website guide.

Pests

The Osorno Blueberry doesn’t seem to be especially susceptible to pests. It still pays to take precaution against the common ones that to the most damage — aphids, blueberry gall midges, and birds.

A bird eating blueberries.
Birds are blueberry thieves to be on the lookout for!

When To Harvest Osorno Blueberries

In mid- to late-July, start checking your Osorno blueberry shrubs for berries that are fully ripe. You’ll need to make multiple trips to your blueberry bush since the fruit doesn’t all ripen at the same time.

To know exactly which berries are ready to pick, visit our guide “When Is the Right Time To Pick Blueberries?

Common Uses For the Osorno Blueberry

While without a doubt the top reason to grow blueberries is for their delicious fruit, they can also serve as beautiful aesthetics for your garden if you’re looking for a new addition to your landscaping scheme.

And because Osorno blueberry plants are relatively smaller than other varieties, you can easily grow them in pots for an easily re-arrangeable display.

But, of course, the primary use of Osorno blueberries is as food. These berries make great snacks and are unique in all kinds of delicious recipes.

What Do Osorno Blueberries Taste Like?

Osorno blueberries have a sweet taste that’s well balanced with medium acidity.

Cooking

A lot of folks only think of blueberries for desserts. However, these sweet, tart, little berries really liven up quite a few dishes, especially those with meats like pork, poultry, beef, and fish.

Savory dishes like Flank Steak With Blueberry Sauce and Mushroom & Blueberry Balsamic Pot Roast are just a few examples.

And, of course, you have your cakes, pies, and ice cream.

Glasses of blueberry yogurt with fresh whole blueberries.

Eating Raw

Osorno blueberries are also wonderful when eaten raw. You can enjoy a bowl as a snack or try a few in your oatmeal, cold cereal, or yogurt. They are also great as an ingredient in salads.

Canning Blueberries

We don’t recommend canning blueberries for preservation purposes. However, if you’re thinking about making your own jams and preserves, you can find tons of fantastic recipes for your fresh blueberries online.

Freezing Blueberries

Freezing is the number one method we recommend for preserving your blueberries. To begin this process, you first need to wash and rinse your berries.

Once this is done, line a cookie sheet with a few layers of paper towels and put your blueberries on top.

You then take a few paper towels and gently blot them until they are as dry as possible — just be careful not to blot too hard.

The last step involves placing your blueberries on a cookie sheet, but you want to make sure there’s a bit of space between each berry. You’ll place your cookie sheet in your freezer like this. If your berries touch, you could end up with a big frozen berry blob, and your berries will lose their natural shape.

Bag of frozen blueberries.

Drying Blueberries

For the best results, we recommend employing a food dehydrator to dry your blueberries. However, you can also accomplish this goal using your oven. Just place your blueberries on a cookie sheet lined with parchment paper. Next, bake them for at least three hours at a temperature of 225 degrees Fahrenheit.

Ensure your berries are thoroughly cooked before removing them, and allow them a few minutes to cool before placing them in ziplock bags or airtight containers for storage.

Recipes for Osorno Blueberries

You can find lots of fantastic recipe ideas on our Minnetonka Orchard website. You can even substitute blueberries for recipes that use different fruit. Here are a few examples of the delicious recipes you’ll find on the website.

Health Benefits of the Osorno Blueberry

Blueberries truly have it all. Not only are they a sweet alternative to candy, but they are also one of the most nutrient-packed superfoods in the world.

Fresh blueberries in small basket.

Every blueberry is loaded with vitamin C, manganese, vitamin K, fiber, potassium, and many antioxidants.

A few conditions blueberries have positive effects on include:

  • Weight control
  • Stroke recovery
  • High blood pressure
  • Cognitive disabilities and dementia
  • Colon cancer

You can also learn more helpful information about the incredible nutritional benefits of blueberries by reading this comprehensive guide on the Minnetonka Orchards website.

Where To Buy Osorno Blueberry Bushes

You might be able to find a few Osorno blueberry bushes at your local nursery or by contacting a Michigan-based nursery. They don’t appear to be available through the better-known online retailers at this time.

Where To Buy Osorno Blueberries

To buy Osorno blueberry fruit, you can try asking your local nursery, visit a local specialty grocery store, or check your local farmers markets as blueberry season approaches.

Final Thoughts on the Osorno Blueberry

Closeup of clusters of ripe blueberries.

The Osorno Blueberry is a vigorous, productive bush that produces fantastic quality fruit and can tolerate warmer temperatures better than many other highbush varieties. However, they struggle in extremely cold conditions, and one should remember they will spread out a bit instead of growing strictly upright. However, this midseason berry can be a real winner in your orchard or garden for growers in regions with mild winters.

Have a tip to share about Osorno Blueberries? Leave it in the comments section below! For other blueberry information, click here for our blueberry-related blog posts.