Packed with antioxidants, beautiful spring flowers, and gorgeous autumn foliage – these are just some of the reasons blueberries are an increasingly popular edible plant to grow at home. However, if you’re finding that your blueberries are smaller than you’d like, you’ll want to know the reason.
The most common reasons blueberries are small are due to the wrong soil pH, a lack of soil nutrients, inconsistent watering, a lack of pruning, or a lack of pollination.
Smaller blueberries can also be the result of the variety you are growing. It’s not always a sign that something’s wrong and it won’t necessarily mean they’re not as tasty.
If your blueberries being small is due to environmental factors rather than the cultivar you’ve planted, there are a number of things you can do to try to resolve this. In this article, we’ll be covering the causes and solutions of blueberries being small so that you can confidently set your bushes on the path to a healthy harvest.
The Wrong Soil pH Causes Small Blueberries
Blueberries are a crop that requires acidic soil to grow properly. Many edible crops do well in soil that is only slightly alkaline or acidic, but blueberries require a pH between 4.0 and 5.5 if possible. Without the right soil acidity, it’s highly unlikely that the blueberry plant is going to be able to thrive or produce healthy blueberry yields.
Amending the pH of your soil can’t be done overnight, particularly if you’re looking to shift the acidity significantly. Forward planning is therefore key when it comes to planting your blueberry bushes.
Sulfur soil is usually the most reliable way to significantly shift the acidity of a patch. However, this will need to be done at least a year in advance to give time for the changes to take effect. You may also need to reapply it annually to maintain the proper pH.
Other popular methods, such as coffee grounds, organic matter, peat moss, or pine needles, can help maintain acidity but are unlikely to be acidic enough to significantly shift the pH of your soil overall.
It’s worth checking the pH with a monitor like this one, of your soil before planting your blueberry bushes (or any crop for that matter). If your pH is above 7, and you are keen to get your blueberry bushes going as soon as possible, it might be worth growing them in containers instead.
In containers, soil pH can be controlled and altered more easily. You can grow your blueberry bushes in an ericaceous potting mix and use ericaceous fertilizer to maintain acidity. Ericaceous essentially just refers to plants that require acidic soil in which to grow.
Even though I have a large enough garden space to grow blueberry bushes in the ground, I prefer to grow them in pots. And this is because I have more control over the soil acidity.
Lack of Soil Nutrients Causes Small Blueberries
The good news is that, once you get the acidity of your soil right, your blueberries should prove to be quite resilient. They’re not a bush that necessarily requires heavy feeding. Though ensuring the garden is dug through with plenty of well-aged organic matter prior to planting will give them the best possible foundation.
Unless the soil is particularly deficient, blueberries may not need more than a late-winter, annual application of ericaceous mulch and high nitrogen feed.
If you are growing blueberries in containers, they’ll benefit from a slow-release organic fertilizer monthly throughout the growing season. Nutrients in the soil will be more easily depleted by the blueberry plant when kept in a container, hence the monthly application of fertilizer.
Lack of Pollination Causes Smaller Blueberries
Pollinators are vital for blueberry bushes to set seeds and fruit. The more seeds are produced as a result of pollination, the bigger the blueberries.
Some blueberry bushes may be marketed as being ‘self-pollinating’. However, in order to get the best possible yields you should plant a minimum of two different varieties close to one another. If possible, planting 3 or more varieties is even better.
There are a number of advantages to this. Firstly, greater cross-pollination will likely result in healthier, larger blueberries and better harvests. Secondly, having a range of blueberry varieties can help diversify and potentially extend your harvest. If you go for early, mid, and late-summer fruiting varieties, you can potentially have blueberry yields for months longer than a single cultivar could provide you with.
To encourage healthy pollination, try to ensure your blueberry bushes are kept in a sunny, well-aerated spot. Planting flowering shrubs and annuals can help encourage insects to the garden. Avoid using pesticides or harmful chemicals on your plants, as these can damage local pollinator populations.
Keep in mind, that creating a healthy ecosystem can not be achieved overnight. It is the result of careful, steady planning and numerous individual gardening choices over time. Choose organic methods, plant a variety of crops, and keep your garden as bee-friendly as possible.
Inconsistent Watering Causes Small Blueberries
Blueberry bushes don’t need to be flooded with water to produce healthy, juicy berries. They do, however, benefit from consistently damp soil. These bushes have a shallow root system. This means they require consistent levels of moisture near the surface in order to be able to stay properly hydrated.
Drip irrigation works really well for blueberry bushes. This can avoid saturating the roots, which can be an issue. Planting your blueberry bushes in well-draining soil can also avoid overwatering.
Proper Pruning Can Help Your Blueberry Bushes Produce Larger Berries
Blueberry bushes are a plant that benefits from judicious pruning over the course of their lifespan. Proper pruning encourages healthy new growth. It also focuses the blueberry plant’s fruit production energies in the best locations. And pruning can extend the overall life span of the blueberry bush.
The best time to prune blueberry bushes is in late winter or early spring. You want to prune after the last bouts of extreme cold have ended but before new growth has really begun. You’ll also want to be able to see buds starting to form.
The healthiest, fattest blueberries are likely to form on thicker lateral growth, rather than on small, spindly branches. Short, weak laterals can produce fruit, but the blueberries are likely to be smaller and the quality may be impacted.
For this reason, it’s a good idea to prune what’s often called ‘twiggy’ growth from your blueberry bush. This also includes stems growing horizontally out near the base of the bush. These are likely to be shaded by foliage higher up and are therefore unlikely to produce much fruit.
A common piece of advice is also to prevent newly planted blueberry bushes from producing fruit at all in their first couple of years. This encourages the blueberry bush to establish itself and its root system, rather than focusing prematurely on fruit production. This can help produce healthier, fatter blueberry harvests in later years.
To stop the blueberry bush from producing fruit early on, simply remove fruit buds as they appear. These will be towards the final inches of last year’s growth and tend to be larger and plumper than leaf buds further down the stem.
Once your blueberry bushes are properly established (4-5 years old) it’s a good idea to remove about 20 percent of the canes each year. Prune the oldest ones. This encourages new, healthy growth and can help the plant renew itself. This, in turn, will help your blueberry bush to produce the biggest, healthiest berries possible.
If you’re looking for a detailed visual guide on pruning blueberry bushes, check out this link.
Understand Your Variety of Blueberry Bush
Some varieties of blueberry are always going to produce smaller fruits. This isn’t necessarily a problem in terms of taste or health benefits. In fact, larger berries don’t necessarily mean sweeter berries.
Understand your variety before you plant it. As we’ve seen, blueberry bushes benefit from forward planning and preparation. Once your blueberries are in the ground, they could be there for years. So it’s best to get the right blueberry variety based on your preferences and garden type.
If the size of your fruit is important, some popular cultivars known for producing larger blueberries include ‘Duke’ and ‘Spartan’.
Remember, in order to maximize cross-pollination and fruit yield, you’ll want to plant a number of different varieties together. Try opting for a range of early, mid, and late-summer varieties to extend and diversify your harvest.