I belong to several gardening groups and one of the most common complaints I see is “why do I have tons of flowers, but I don’t have any fruit?” This problem of having flowers but no fruit happens to both beginner and seasoned gardeners and can strike at any time. It also can happen to a variety of plants. I consulted my friend, and Master Gardener Hillary Swetz and she was able to give me expert advice about fixing the fruitless problem.
Luckily, there’s good news and bad news. The good news is, MOST of the time, you have a very solvable problem. The bad news is that some of the time, there’s really nothing you can do (except maybe to wait).
Here are the top five most likely reasons why your plants are loaded with flowers but don’t have fruit.
#1- Male vs. female flowers
Some plants produce two different kinds of flowers- both male and female. Strange, but true! These plants have some flowers that just produce pollen and some flowers that just receive it. The most common plants of this type in the Victory Garden are those in the cucurbit family. This means cucumbers, summer and winter squashes, pumpkins, and watermelons will all produce MANY flowers, but only half will ever become fruit.
You can tell the difference by looking at the base of the flower. Male flowers will have a simple stem that connects them to the main vine. Female flowers, on the other hand, will have tiny rounded or elongated bulbs that connect them to the vine- that’s the baby fruit.
Especially around the beginning of the flowering season, many plants focus heavily on producing just male flowers to make sure there’s plenty of pollen produced to pollinate the females. This could lead gardeners to fear there’s something wrong with the plant- after all, it’s producing so many flowers that lead to nothing! But just give your garden time and the balance between male and female will even out.
If you’re looking at your cucurbits and confused about all the flowers not becoming fruit, don’t worry! You need to first make sure you’re looking at female flowers. If you’re 100% sure you’ve got plenty of female flowers, and 100% sure they’re drying up and not producing any fruit, read on to see if any of the other causes apply to you.
#2- No pollination
This is a problem that I have experienced first hand – no bees! You’ve probably heard in the news recently that bees are dying at a rapid rate. Mostly this refers to the honey bee, but native bees aren’t faring much better. Overuse of chemical pesticides has directly killed off many pollinators or made them more susceptible to disease.
The next time you’re in your garden, look for bees. Remember not to just look for those fuzzy bumblebees or the common honeybee. Try googling “native bees + [your location]” to see what others might look like. You can also look for hummingbirds, butterflies, and moths, as they’re also high-powered pollinators
If it seems like your garden is experiencing a pollinator strike, you’ll need to hand-pollinate your plants. The easiest way to do this is to grab a paintbrush, a cotton swab, or even your finger. Gently find a male flower and touch the middle spike covered in pollen. Then, transfer the pollen over to a female flower by swishing your brush/swab/finger around its inside.
Alternatively, you could look into becoming a beekeeper and have a guaranteed workforce of pollinators in your own yard!
#3- Too much nitrogen
Just like in humans, different kinds of food produce different results in a plant. For plants, an overabundance of nitrogen will cause them to focus on producing lots of leafy greens, few flowers, and hardly any fruit.[1]
You might have too much nitrogen if you recently dumped a big load of compost or fertilizer on them that was imbalanced. While it’s true that you want to fertilize your plants (especially heavy feeders like tomatoes), OVER-fertilizing is unhelpful.
Instead, feed your tomatoes (and other heavy feeders) a fertilizer high in potassium, not nitrogen, when flowers appear. The most common potassium fertilizer is called potash. However, you can add potassium most cheaply by sprinkling some ashes from a recent campfire or your wood stove around the base of your plants.
#4- Temperature dips or climbs
Some plants like tomatoes are just finicky. They’re not as dependent on bees to pollinate them since a gust of wind will pollinate them just fine, but they do have other problems. Night temperatures below 50°F mean pollen production will suffer and flowers will not get fertilized. You also will get poor yields if night temperatures are above 75°F in addition to having days with 95°F and dry, windy weather.
If your tomatoes have flowers but no fruit, and it’s been hot recently, this is likely your problem. Unfortunately, there’s not much you can do to help your plants when the temps climb super high, except to keep them watered. This will make sure they’re healthy enough to produce properly when the weather cools off.
#5- Male vs. female plants
In tip #1, I told you some plants have both male and female flowers. But now I’m going to really blow your mind. Some plants are entirely male or entirely female!
If you have asparagus, mulberry, currants, spinach, holly, or ginkgo trees, you won’t get any fruit unless you have at least one male and female of each variety. Otherwise, your plant will produce plenty of flowers, but they’ll all be male (and therefore unable to produce fruit) or all female (and therefore won’t get pollinated).
So straight from the expert! Five of the most likely reasons why the plants in your garden have flowers but no fruit.
I would love to know if this solved your problem!
Happy planting!
DeeAnn
The Victory Garden Gal
Featuring Hillary Swetz Master Gardener
[1] http://www.mggkc.org/vegetables-produce-flowers-but-no-fruit/