Potatoes are in the Solanaceae family, also known as the Nightshade family. Potato plants have pretty purple flowers that remind us that potatoes are related to peppers, tomatoes, and eggplants.
You probably already knew this, but the part of the potato plant we want to eat grows below the ground. It’s the spud, also called the tuber, that we dig up at the end of the plant’s life cycle.
But maybe you didn’t know that the parts of the plant that are above ground are a good way to remember that deadly nightshade, also known as belladonna, is a potato cousin. Yes, potatoes can make a berry that looks a bit like a green tomato. The leaves, flowers, and fruit of potatoes are all poisonous. Not kill-you-instantly-poisonous, but you definitely wouldn’t feel great for a bit.
If you’ve grown potatoes before, you may have noticed delicate purple, white or pink blooms sprouting from the tops of your plants. This flowering is a natural stage in the potato plant’s development. But what causes potatoes to flower and should you be concerned when you spot these blooms in your vegetable patch? Here’s a closer look at what it means when potato plants flower.
Why Do Potato Plants Bloom?
Flowering is part of the natural reproductive cycle of the potato plant Like all plants in the nightshade family including tomatoes, eggplant and peppers, potatoes will produce flowers under the right conditions
The flowers appear so that the plant can be pollinated, set seed and reproduce. While we cultivate potatoes for their tasty underground tubers, left alone, they will focus energy into flowering and going to seed.
Potatoes are sensitive to day length, or photoperiod As daylight hours shorten, mature potato plants interpret this as a sign winter is coming and the end of their lifecycle is near This triggers a survival mechanism – the plant hurries to set seed and reproduce before it’s too late.
The age of your plants also influences flowering. Generally, you’ll see blooms appear on potato plants that are 50-70 days old. Older, more established plants have the resources and energy available to direct toward flowering.
Typical Flowering Times
Blooming tends to occur in mid to late summer, but the exact timing depends on the potato variety.
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Early season potatoes bloom earlier, around late June or July.
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Midseason potatoes bloom in July and August.
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Late season potatoes bloom late July through September.
The time to maturity can vary quite a bit between different potato varieties. Early potatoes are the quickest to reach flowering stage while late season potatoes take longer.
Does Flowering Impact Tuber Production?
Many home gardeners wonder if allowing potato blooms to remain on the plants will reduce the yield of edible tubers. The short answer is yes, flowering and fruiting does divert energy away from tuber production underground.
However, removing all flowers isn’t always necessary. Potato plants are capable of supporting some flowering while still providing a good crop of potatoes.
The exception is varieties grown specifically for their heavy yields. For these, diligently removing all flowers can maximize the size and quantity of potatoes produced.
Managing Potato Flowers
If you want to maximize potato production, regularly pinch or cut off any flowers that appear. This is called “de-flowering”. Focus on removing flowers when plants first start to bloom, before they have a chance to develop into fruits or seed pods.
Use sharp, clean pruners or scissors to snip flowers right at the base of the stem. Make cuts on a dry day to prevent disease infection.
Aim to remove blossoms at least once a week while plants are flowering. This prevents them from redirecting too much energy into seed production.
Let a few flowers remain if you want to collect potato seeds for planting next year or are curious to observe the lifecycle. Just monitor for poisonous berries that could tempt kids or pets.
Does Prolific Flowering Indicate a Problem?
Sometimes potato plants bloom heavily, with flower stalks appearing crowded together. This is often a sign of stress. Causes can include:
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Over-fertilization –too much nitrogen can trigger excessive flowering.
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Extreme temperatures – heat and cold stress may induce emergency flowering.
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Poor soil conditions – compacted or waterlogged soil inhibits tuber growth.
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Insufficient sunlight – plants may shift efforts to flowering and seeds.
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Shock or trauma to the plants like hail damage or herbicide drift.
Rampant flowering doesn’t necessarily doom your crop, but both the plant and tubers will likely be smaller. Try to identify and correct the source of stress to prevent stunted growth.
A Natural Part of Growth
Potato flowers indicate your plants are mature and progressing through their natural life stages. Moderate blooming is normal, but pinch off flowers to keep your crop’s energy focused on swelling those tubers for harvest. With the right care, your potato patch will keep producing bountiful spuds all season long.
Why Do Potatoes Produce Flowers?
Like most flowers, potato plant flowers show up at the end of a plant’s life cycle to attract pollinators that will help the plant reproduce and make more plants for the future. It’s possible for flowers to mean that the plant has started to make tubers underground. On the other hand, flowers could mean that the plant has been given too much fertilizer, which can make it flower too quickly. Very high or very low temperatures can also push a plant to grow quickly and make more plants before its best growing season ends.
What to Do When Your Potato Plant Flowers
When you see flowers on your potato plants, I recommend cutting them off for two main reasons.
To begin, you don’t want the flowers to make fruit that pets or small children might want to eat.
Secondly, pruning the flowers is a great way to increase production of spuds. When a plant flowers, it sends some of its energy to the flower so that it can make fruits and seeds. But we want that energy to go to the part we eat, which is below ground.
You can cut the flowers back by cutting right at the stem’s base with scissors or gardening shears. This tells the plant to stop sending its energy to seed production and to keep producing tubers. Pruning is such an effective way to direct the plant where you want its energy to go.
Worried you dont have the resources or time to grow your own potatoes or other delicious vegetables?
What to Do When Your Potatoes Flower: How to Maximize Spud Production and Avoid Poisonous Fruit
FAQ
How long after potatoes flower are they ready to pick?
What to do with potatoes when they flower?
Do potatoes continue to grow after flowering?
What color are potato flowers?
Potato flowers are commonly compared to tomato flowers in appearance, but instead of being yellow, they are either a shade of lavender, pink, or white. In some cases, the fruit will begin to form inside the flowers. The fruit in the center is small and yellow and resembles a tomato, however, these are not to be eaten under any circumstances.
What causes potato plants to flower?
A potato plant flowers as it gets closer to maturity and signals that “new potatoes” (small tubers) are ready for harvest. Cold, wet weather can also make potato plants flower. Flowers on a potato plant indicate that its tubers (the edible part of the plant that grows underground) are starting to form.
Are potato flowers edible?
The majority of potato flowers are small, yellow, or white blooms that look nice but aren’t edible. Don’t eat the leaves or flowers of a potato plant as they contain a substance called solanine which is toxic. This compound can cause some nasty symptoms when ingested by humans or animals, including diarrhea, abdominal pain, and headaches.