In the life of a gardener, few things are sadder than nurturing a plant, harvesting the tasty fruit or veggie, eating it… and discovering that it tastes terrible.

A close up vertical image of a freshly harvested bunch of celery stalks on a wooden chopping board set on a wooden surface. To the top and bottom of the frame is green and white printed text.

This happened to me a couple years ago with the carrots I grew and forgot to fertilize regularly. It can happen with all sorts of plants, including other Umbellifers – like celery.

And since it is already a strong-tasting veggie, the last thing you want is for those stalks to taste so acrid you can barely stand to eat them. What a sad culmination of your growing efforts!

If you’ve ever harvested disappointingly unappealing Apium graveolens or want to make sure your current crop zips with tasty but not overbearing flavor, this article is for you.

You can learn more about growing celery in your garden in our guide.

Here’s what I’ll cover in this article:

1. Not Enough Nutrients

As I discovered with my bitter carrots, a lack of nutrients can result in a poorly fed, bitter-tasting plant.

When I was new to gardening, I didn’t think too hard about the soil where I planted my seeds.

A close up horizontal image of rows of Apium graveolens growing in the garden with dark soil in the foreground.

I usually just dumped some potting mix from the store into a little raised bed, and that would adequately feed my herbs, flowers, and small collection of veggies for the summer.

My mom had a compost pile where I dumped eggshells and carrot peels to become smelly mush, but as a teenager I didn’t really make the connection between the compost pile and the plants in the garden.

A close up horizontal image of a compost pile with food scraps, it looks quite disgusting actually.

After a few rounds of harvesting acrid vegetables, I realized that getting the soil composition right and feeding the plants regularly is crucial if you want to eat homegrown produce that tastes good.

To put it simply, if you aren’t giving the plants what they need in order to thrive, they suffer. And an undernourished plant won’t taste nice.

Celery is a heavy feeder, but it’s an easy plant to nourish.All it needs is an application of balanced fertilizer every three to four weeks in order to stay happy.

A close up square image of the packaging of Vigoro Tomato and Vegetable Garden Plant food.

Vigoro Tomato and Vegetable Plant Food

I like to use this 12-10-5 (NPK) product from Vigoro, available at the Home Depot.

It’s also a good idea to amend your soil with compost or well-rotted manure before planting your celery, giving it a nutrient-rich place to grow.

2. Too Much Heat

Celery thrives in places where nights are a cool 50°F and days don’t exceed 70 to 80°F. If temperatures rise into the 90s – especially as the stalks reach maturity – the heat can cause the stalks to turn bitter.

A close up top down horizontal image of two small Apium graveolens plants growing in the garden surrounded by straw mulch.

To protect your plants during heatwaves, water them early in the morning to keep the soil moist and cool throughout the day, and mulch with straw or another light-colored material.

This helps to keep the soil and roots from overheating.

You can also erect a shade cloth that blocks 30-50% of the light, like this one from Amazon, leaving it up during the hottest parts of the day.

3. A Lack of Water

If it doesn’t get enough water, celery can produce stringy, bitter stalks. Each plant needs at least one to one and a half inches of water every week, and if it doesn’t get that moisture, it’ll get stressed.

A close up vertical image of a hand holding a spray hose watering a small Apium graveolens plant in the garden.

So make sure you’re consistently watering your plants. If you’re prone to forgetting, as I sometimes am, set a daily reminder on your phone to check the moisture level of the soil.

If you poke your finger three inches down and feel dryness, it’s time to water the thirsty plants.

4. An Overly Mature Plant

Cheese and wine may become perfect with age, but celery does not.

It can be tough to know when to harvest the verdant stalks, but if you wait too long, you risk harvesting tough, bitter, stringy celery.

A close up horizontal image of Apium graveolens stalks sliced.

Yuck!

Thankfully, there are two easy ways to know when your plant is ready for harvest:

1. It’s been about 130-140 days since the seedlings germinated.

2. Stalks are six inches long from the base to the first leaf.

So get out your ruler and do some measuring. And check your gardening journal, in which you hopefully marked the date of germination if you grew the plant from seed.

If you need extra help figuring out when to harvest, check out our guide to harvesting celery for more tips (coming soon!).

5. Stalks That Haven’t Been Blanched

Maybe you gave your plants the right amount of water and fertilizer, kept them cool in hot weather, and harvested the stalks at the right time, but they’re still bitter.

Why?

Take a look at the color. Are the stalks a bright, deep green?

A close up horizontal image of celery in the garden being blanched using milk cartons, pictured in bright sunshine.Photo by Laura Melchor.

For sweeter stalks, you’ll want to blanch the celery in the garden by covering them with newspaper or milk cartons about two weeks before harvest.

This blocks the sun from reaching the stalks, preventing photosynthesis and chlorophyll production, and resulting in a sweeter, lighter-colored plant.

A close up horizontal image of celery stalks, some of them that have been blanched and are pale in color, others are darker.Photo by Laura Melchor.

In the photo above, the stalks on the left-hand side have been blanched, while the stalks on the right-hand side have not.

For more details on how and when to do this, check out our guide to blanching celery in the garden.

You can also grow self-blanching varieties, like ‘Golden Self-Blanching.’

If it’s too late to blanch – maybe you’ve already harvested all your plants – tease the head apart to find the lighter, naturally blanched inner stalks.

These will taste sweeter than the outer stalks, so they’re ideal for when you want to enjoy a raw stick or two for an afternoon snack.

Use the greener stalks for cooking. As you’ll see in a moment, cooking the bitter stalks can help to improve their flavor.

What to Do with Bitter Celery

Now that you know how to prevent bitter flavors from developing in your celery, you can keep your next crop healthy and sweet.

But what if you already harvested celery that’s tough, stringy, and bitter? What can you do with it?

Try cutting it into small pieces and sauteing it in butter until it begins to turn tender, and then add it to this vegan Thanksgiving stuffing from our sister site, Foodal.

Sauteing it will soften the harsh flavor but help it to retain its crisp texture in your stuffing.

A top down horizontal image of two bowls of winter vegetable soup set on a white and red tablecloth with grated parmesan in the background.Photo by Meghan Yager.

Or, simmer it into Foodal’s delicious, autumn-appropriate vegetable minestrone.

Like sauteing, the act of simmering or boiling the celery in a soup like this one brings out its milder side.

A close up horizontal image of a plate of roasted vegetables with sliced parmesan on the top, set on a wooden surface.Photo by Fanny Slater.

To transform it into a tasty side dish, try caramelizing and roasting it along with onions, mushrooms, carrots, zucchini, and other scrumptious veggies in this recipe for a roasted vegetable and herb salad, also from Foodal.

See? Even if you harvested a bunch of bitter stalks, it doesn’t mean your hard work was for naught. There’s still plenty you can do to make acrid stalks shine.

A Sweet Cel(ery)bration

I hope this article has lifted your spirits if you recently took a huge bite of garden-grown celery and nearly wilted at the overwhelming flavor.

Or maybe it caught you in time to blanch the stalks, or add a bit of fertilizer, water, or protective shade cloth to your stressed-out plants.

A close up horizontal image of celery leaves covered in light droplets of water pictured on a soft focus background.

If you have any additional tips to salvage bitter celery, share your advice in the comments below!

Now, go forth and grow yourself some sweet-tasting stalks.

And remember to check out these articles on growing flavorful Umbellifers in your garden next:

Photos by Fanny Slater, Meghan Yager, and Laura Melchor © Ask the Experts, LLC. ALL RIGHTS RESERVED. See our TOS for more details. Product photos via Amazon and Home Depot. Uncredited photos: Shutterstock.

About Laura Melchor

Laura Melchor grew up helping her mom in the garden in Montana, and as an adult she’s brought her cold-weather gardening skills with her to her home in Alaska. She’s especially proud of the flowerbeds she and her three-year-old son built with rocks dug up from their little Alaska homestead. As a freelance writer, she contributes to several websites and blogs across the web. Laura also writes novels and holds an MFA in writing from Vermont College of Fine Arts.