What Are The Red Berries On My Asparagus Plants? (Asparagus Berries)


If you grow asparagus in your garden, you may see little red berries growing on some of the plants.  I did some research to find out what these red berries are and why they only grow on some plants.

So, what are the red berries on your asparagus plants?  The red berries on an asparagus plant contain seeds, which are used for reproduction.  These red berries usually only grow on female asparagus plants, although both male and female plants have flowers.  Both male and female plants must be planted together in order for female plants to produce these berries.

Let’s start off by taking a closer look at the differences between male and asparagus plants, along with ways you can get more plants.  Then we’ll find some answers for commonly asked questions about asparagus plants, berries, and seeds.

What Are The Red Berries On My Asparagus Plants?

According to Wikipedia, asparagus is a perennial flowering plant that is dioecious.  Dioecious means that there are separate male and female asparagus plants.

On occasion, hermaphrodite (both male and female) flowers may appear.  Asparagus plants can live for up to 30 years!

For more information, check out this article on asparagus from Wikipedia.

The red berries you see on some asparagus plants contain seeds.  However, these seed-containing berries usually only grow on female asparagus plants.

asparagus berries
Deep-red asparagus berries usually only grow on the female plants.

When a female plant falls over, the seeds have a chance to germinate in the soil and grow into new asparagus plants.  However, male asparagus plants must be present for berries to appear on female asparagus plants.

Male Asparagus Plants

Male asparagus plants produce small bell-shaped flowers, which are white, yellow, or green.  They also tend to produce more and larger spears than female asparagus plants.  This means that if you want a bigger harvest of edible asparagus spears, then you should opt for male plants.

asparagus
Male asparagus plants tend to produce larger spears.

Thanks to the wonders of science, you can now order all-male hybrid asparagus plants (thank Rutgers University for that!).  These all-male hybrid varieties can produce three times more than traditional asparagus varieties.  For more information, check out this article from Mother Earth News.

In addition, these all-male hybrid varieties will not produce seeds, according to this article on asparagus from Extension.org.

Female Asparagus Plants

Female asparagus plants also produce flowers, which look similar to those produce by male asparagus plants.  Female plants are usually the ones to produce berries, which are bright red and 0.5 to 1.0 centimeters in diameter.

asparagus berries
Female asparagus plants are usually the ones to produce berries.

If you want to grow more asparagus from seeds, you will want some female plants in your garden.  However, there is a trade-off to be made.

Since female asparagus plants devote energy to producing seeds, they have less energy leftover for growing the edible spears.  This means that spears from female asparagus plants will be smaller, thinner, and less numerous than those found on a male plant.

How Do I Tell Male and Female Asparagus Plants Apart?

There are a couple of ways to tell male and female asparagus plants apart: by the berries, by the flowers, and by the spears (stalks).

To tell male and female asparagus flowers apart by their berries, you will need to wait until the fall.  At this point, berries will start to appear on the female plants.

However, this method is not foolproof.  First of all, if you have heirloom asparagus varieties, some of the male plants may produce berries.  (As mentioned before, all-male hybrid varieties will not produce berries.)

Second, if all of your asparagus plants are female, then they may not produce berries at all.  The reason is that male plants need to be present and close by in order for female plants to produce berries.

So, you could end up mistaking male plants for female plants, or vice versa, if you are only using berries as your criteria.  A better way is to look at the flowers on each plant, which appear in the summer.  Then, use the berries in the fall as a confirmation.

To tell asparagus plants apart by their flowers, you will need to pay attention to a few details.  First, the flowers on male plants are longer than the flowers on female plants.  Second, the male flowers have six stamens around a pistil, whereas female flowers have six pistils and one stamen.

For more information, check out this article about asparagus flowers on garden.eco.

Of course, you can always take a look at the asparagus spears themselves – they will usually be thicker and more numerous on male plants.

How Do Asparagus Plants Reproduce?

There are two ways that asparagus plants can reproduce: by flowers and seeds (flowering), or by root cuttings (vegetative).

Asparagus Reproduction By Flowers and Seeds (Flowering Reproduction)

This type of plant reproduction is the way that most people think of.  However, asparagus is unusual in that it has two separate genders of plants, instead of having both male and female flowers on the same plant.

Asparagus reproduction begins when a pollinator (such as a bee, a hummingbird, etc.) travels from flower to flower in search of nectar.  In the process, the pollinator gathers pollen on its body from one flower and spread it around to other flowers.

bumblebee
Bees and other pollinators can help asparagus plants to reproduce by flowers and seeds.

When a male pollen grain lands on a female stigma, fertilization may occur.  If successful, a berry will eventually form on the female plant where the flower was.  At the end of the growing season, the stalks of the female plant will fall over.

The berries will land on the ground, some of them being buried by wind, rain, or animals.  Eventually, some of the seeds inside the berries will germinate underground and produce new asparagus plants.

For more information, check out this article on pollination from the University of Georgia.

Keep in mind that when you propagate (reproduce) asparagus plants by seed, there is no guarantee that the resulting plants will be the same as the mother plant.  This is because the seed has genetic material from both parent plants, and the resulting offspring can be a completely different asparagus plant.

Asparagus Reproduction By Root Cuttings (Vegetative Reproduction)

On the other hand, if you want to propagate more asparagus plants that are the same as the parent plant, then vegetative production is the way to go.  In vegetative reproduction of asparagus plants, you wait for new plants to sprout underground, since the root systems do not die back in the winter.

Usually, gardeners buy asparagus crowns from nurseries.  These crowns were grown from seed, and are one or two years old.  You can start harvesting spears from these plants when they are three years old.

Frequently Asked Questions About Asparagus

There are a few more questions you might have about asparagus, so let’s try to answer them here.

How Long Does It Take For An Asparagus Plant To Produce Seeds?

A mature asparagus plant (3 years old or older) will produce tender, edible spears for 4 to 8 weeks in the early spring.  After that, the spears will become tougher, especially at the bottom, and the tips will open up and develop into what look like ferns.

This fern-like growth will yield berries on female plants in the summer or fall.  If the weather is especially hot and dry, female asparagus plants may start to produce berries earlier.

How Do I Harvest Asparagus Seeds?

To harvest asparagus seeds, wait until a female plant produces berries.  When the berries turn red, pick them from the plant and remove the seeds.

Clean the seeds off and let them dry out before putting them in a jar for storage.  They may be viable for 2 or 3 years, but it is best to plant them the next year.

Remember that these asparagus seeds may not produce plants that are the same as the parent plant.  You may want to consider buying asparagus seeds from a reputable seed company instead.

For more information, check out my article on the difference between organic and heirloom seeds, and my article on the pros and cons of hybrid seeds.

Should I Remove Female Asparagus Plants From My Garden?

If you want to increase your harvest of asparagus spears, it might make sense to remove female plants from your garden.  This frees up space for all-male hybrid varieties, which produce larger and more numerous spears.

Removing female asparagus plants also prevents the berries from falling and producing new plants from seed, which may compete with existing plants.  Scroll back up for more information on how to tell male and female asparagus plants apart.

Are Asparagus Berries Toxic?

Yes, asparagus berries are toxic to humans, dogs, and cats.

dog
Asparagus berries are toxic to dogs, so keep them away!

For more information, check out this article on asparagus berries from garden.eco.

Conclusion

By now, you have a better idea of why you are seeing red berries growing on your asparagus plants.  It is not a cause for alarm, but it does mean that some of your plants are putting energy into reproduction instead of producing asparagus spears for you to eat.

I hope this article was helpful – if so, please share it with someone who can use the information.  If you have any questions or advice of your own about asparagus plants, berries, or seeds, please leave a comment below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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