It can be frustrating to see your blueberry bushes flowering, but not producing any fruit. It is even more frustrating when you don’t know why. Let’s shed some light on the reason you are not getting blueberries.
So, why does a blueberry bush flower, but not produce fruit? Lack of pollination will prevent a blueberry bush with flowers from producing fruit. Also, a blueberry bush that is too young may flower well, but not produce any fruit. In addition, planting the wrong variety of blueberry bush for your climate can also prevent fruiting. Finally, a soil pH that is too high will prevent a blueberry bush from developing and fruiting properly.
Remember that flowers appear on blueberry bushes in late spring, and fruit appears in early summer. If you don’t see blueberries around this time, then you should try to troubleshoot the cause of the problem.
Let’s start off with pollination for blueberry plants: how it works, when it might fail, and how you can help things along. Then we’ll look at some of the other factors that can prevent fruiting.
Cause #1: Lack of Pollination for Blueberry Bushes
If your blueberry bush has plenty of flowers, but no berries, a lack of pollination is a likely cause. A lack of bees or extreme weather conditions will both prevent your blueberry bushes from producing fruit. Let’s look at how pollination works, how it can fail, and how you can solve the problem yourself.
How Pollination Works for Blueberry Bushes
Some blueberry varieties are self-pollinating. This means that the flowers contain both male and female parts. The male part of the flower releases pollen onto the female part of the flower to allow for pollination and fruit production.
However, self-pollination does not mean automatic pollination. Whether self-pollinating or not, blueberry bushes still need help from pollinators (mainly bees) to produce fruit.
Having more than one blueberry bush (with 2 or 3 different varieties) will allow bees to cross-pollinate your blueberries. This increases the chances of successful pollination. This means more fruit and larger berries at harvest.
When Pollination of Blueberry Bushes Might Fail
A lack of pollinators or extreme weather conditions can both cause pollination to fail.
Bee populations have been declining in recent years, partially due to increased use of pesticides for farms, gardens, and lawns. If you notice a lack of bees, avoid using pesticides, and plant flowers or clover to attract bees to your yard.
You might also ask your neighbors to do the same, to create a larger “safe haven” area for bees to live in.
Even if there are plenty of bees in your yard, pollination can fail due to low temperatures. Bees will not be very active if temperatures drop below 50 degrees Fahrenheit.
Even a short stretch of unseasonably cold weather can prevent pollination. After 2 or 3 days have passed after a flower opens, pollination becomes much less likely.
For more information, check out these articles:
How to Hand Pollinate Blueberry Bushes
You may not be able to attract bees to your yard, and you certainly cannot control the air temperature. However, you can try to pollinate your blueberry bushes by hand, as a last resort.
One way to do this is to use an electric toothbrush. First, turn on the toothbrush – the vibration will mimic the vibration from a bee’s wings.
Then, go back and forth between all of your blueberry bushes, touching the toothbrush bristles to each flower to stimulate the release of pollen. You can repeat this a few times a day after flowers begin to open.
Cause #2: Your Blueberry Bush is Too Young
Some people get impatient if their blueberry bushes are not producing fruit immediately. However, it is important to remember that a blueberry bush will not produce any fruit in its first year. In fact, a blueberry bush might not start to produce a decent amount of fruit until years 3 through 6.
There are some steps you can take to improve fruit production of your blueberry bushes. First of all, pinch off the flowers on a bush in its first year, and possibly the 2nd year as well.
This will allow the bush to put more energy into roots and growth. Don’t feel too badly about this – these early flowers which will not produce much fruit anyway!
As your blueberry bush starts to get older, you should think about pruning it every year. Older branches will not produce any fruit, so it is a good idea to prune them back.
Cause #3: Planting the Wrong Variety of Blueberry Bush for Your Climate
It is also possible that you have planted the wrong variety of blueberry bush for your climate. If your winters are too cold (or not cold enough!), then your blueberry bush might not ever produce fruit. In some cases, the bush may fail to even produce flowers.
It is important to remember that a blueberry bush needs a certain period of dormancy in the winter. This means that a blueberry bush is expecting to spend a certain amount of time in cold temperatures. In fact, these cold temperatures are a signal to the bush about when to go dormant and when to emerge from dormancy.
Each blueberry plant needs a certain number of winter chill hours, or hours spent below 45 degrees Fahrenheit. There are low chill and high chill varieties of blueberry bushes.
High chill blueberry bushes need more than 800 chill hours to set fruit. Low chill blueberry bushes can set fruit with less than 800 chill hours.
Planting a low chill blueberry bush in colder regions (such as the Northern U.S.) will lead to the bush flowering too early. This will lead to death of the flowers due to late spring frosts, and lack of fruit.
Planting a high chill blueberry bush in warmer regions (such as the Southern U.S.) means that the bush may never come out of dormancy, never flowering or producing fruit.
To summarize: if you have long, cold winters, plant high chill blueberry bushes. If you have short, warm winters, plant low chill blueberry bushes.
Cause #4: Soil pH is Too High for Blueberry Bushes
Blueberry bushes are somewhat unique in the world of gardening, in that they prefer to grow soil that is more acidic (lower pH) than most other plants can tolerate. As a result, you may need to grow blueberry bushes in an area of their own.
A soil pH of 4.5 to 5.5 (fairly acidic, since a pH of 7.0 is neutral) is ideal for blueberry bushes. Most plants grow best in soil with a pH of 6.0 to 7.0 (slightly acidic), so you may need to make some changes if your soil is not acidic enough.
To find out for sure, you can do a soil test. You can buy your own soil test kit online or at a garden center. You can also send a soil sample to your local agricultural extension, along with an explanation that you are trying to grow blueberries.
One advantage of sending a sample for testing is the detailed information you will receive from the lab. You will get a report on your soil pH and nutrient levels, along with recommendations for how to improve your soil.
For more information, check out my article on soil testing.
If you find that your soil pH is too high (not acidic enough), you can add some elemental sulfur to the soil to lower the pH. There are other ways to lower your soil pH as well.
For more information, check out my article on how to make your soil more acidic (lower soil pH).
There are some other reasons that your blueberry bushes might fail to flower – let’s go over them briefly.
Lack of Sunlight
A blueberry bush prefers an area where it receives full sunlight (6 or more hours of direct sunlight per day). If your blueberry bushes are shaded by trees, they might not be in a good location.
You may want to consider cutting some branches from overhanging trees to allow more sunlight for your bushes.
Too much or too little water can stress your blueberry plants, possibly causing poor fruit production or dropping of flowers.
Blueberries prefer loamy, well-draining soil. You should always feel the soil to a depth of a few inches before watering. If it feels wet, the bushes probably do not need to be watered.
For more information, check out my article on over watering your plants.
You may also find that you have problems with soil that always seems to be too dry. For more information, check out my article on how to treat dry soil.
Nutrient imbalances in your soil can also prevent a blueberry bush from producing fruit. For example, nitrogen is an important nutrient that helps plants to produce green growth, including leaves and shoots.
However, excessive nitrogen will cause a plant to continue producing green growth at the expense of flowers and fruit. If you think this may be a potential problem for your blueberry bushes, check out my article on low-nitrogen fertilizers.
As mentioned earlier, a soil test can tell you if the nutrient levels in your soil are out of balance. Using compost is a good way to replace organic material and nutrients in your soil. For more information, check out my article on how to make your own compost.
A balanced fertilizer is another way to replace nutrients used by your plants. Remember to always do a soil test before adding supplements to your soil.
Birds Eating Your Blueberries
One last possibility is that birds or other pests are eating your blueberries. If you only have a few small blueberry bushes, then the bird population may be large enough to eat all of the berries before you ever get to see them.
One solution is to put up scarecrows or shiny, flashing objects (CDs tied to a string, for example) to scare the birds away. They do learn quickly, however, so you might need to move these objects frequently to maintain the novelty of the scare factor.
Hopefully, this article gave you an idea of what might be preventing your blueberry bushes from producing fruit. Now you know the steps you can take to solve the most common problems.
I hope you found this article helpful. If you have any questions or advice of your own, please leave a comment below.