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Celery has a bitter, strong unless it is blanched.

Ask Gardenerd: When to Blanch Celery

We love this question that came in to Ask Gardenerd this week:

“I planted celery about 6 weeks ago (from the chopped off part of market celery) and it is doing well. The stalks are now about 1/2 inch thick. When do I wrap it and how to make the stalks turn white.” – Audrey Bishop

Thanks for your question, Audrey. Here’s your answer:

Celery sprout
Celery sprout

You’ve got time. Blanching, for those who aren’t familiar, is the process of covering celery stalks to reduce bitterness and lighten the stalk’s color a bit. Blanching produces a sweeter celery stalk that is more in keeping with what you’re used to buying in the grocery store. Unblanched celery is much stronger in flavor and often bitter (and definitely darker green). It does contain more nutrients than its blanched cousin because of that.


According to the National Gardening Association, you only need to cover your celery plants about 10 days before you want to harvest. Other sources recommend blanching for up to 3 weeks before harvest.

Celery has a bitter, strong unless it is blanched.
Celery has a bitter, strong unless it is blanched.

How to blanch

There are several ways to blanch celery in preparation for harvesting. The cheapest way is to pile soil up around the plant, but you run the risk of getting soil deep in the crevices of the plant. We’ve also heard of gardeners using old MJB coffee cans with both lids removed to block out the sun as well.

You can wrap your celery with newspaper and tie it in place with twine, or use a waxed milk carton. Open up both ends and slide it carefully over the plant, allowing the leaves to stick out the top. The plant still needs sunlight to grow, you just want to block exposure to the stalks, as shown below:

Canadian celery speaks French.
Canadian celery speaks French.

So there you  have it; easy tips for blanching your celery plants. Good luck, Audrey, and keep us posted.

Hey Gardenerds, what do you use to blanch celery in your garden? Post your ideas below.

This Post Has 15 Comments

  1. Gideon Waldner

    how do commercial growers blanch their celery? there are like hundreds of acres around coaldale alberta . they can’t very well blanch each plant seperately.

    1. Christy

      Great question. I checked a few sources, and in addition to growing self-blanching varieties, celery is blanched on the commercial scale by trenching. This from Farmer’s Almanac: Trenching celery needs soil mounded up against the stems as they grow to produce crisp, pale stems. To make this easier, trenching celery is typically planted into trenches, hence the name, but some gardeners aid this blanching process using cardboard tubes, pipes or collars.

  2. Dajana

    This is my first time growing celery, and I’m using a container. My intention was to harvest one stalk at a time. Does anyone do this? And if so, I’m assuming you’re skipping the blanching.

    1. Christy

      Great question. You’re right, if you’re going to pick the celery one stalk at a time, you’ll probably skip blanching. I used to do that, but now I blanch and store the celery (wrapped in aluminum foil – it lasts for an unreasonably long time for some reason). Be prepared to have very strong tasting celery. You’ll probably only need 1 stalk in a recipe that calls for several. I also freeze chopped celery for use in cooking later. Works great in soups and stews.

  3. DW Barnett

    Can you use clay tiles for this or would it create too much heat on the plant ? My plants were put in the ground in early June or late May and I am in South-West Ontario. Thanks

    1. Christy

      I guess it depends on the material. Glazed tiles may reflect heat away, but terracotta will absorb. Tile thickness is probably also a factor. It’s worth a try. Set a few tiles out and see how hot they are after a few hours in the sun. Feel both sides and see if one side is cooler. If so, you probably can get away with it as a blocker to blanch celery.

  4. Sameer

    This is interesting at so many levels.

    Here in India – the plants eat the sun and we eat the sun through those plants. So when you open up more of the plant to the sun – more nutrients get into the plant. This is very true when we’re doing aquaponics on rooftops – its the sun that’s top priority.

    Maybe that’s why they do farming far away from cities – the sun is available to the ground for a longer duration in the day.

    1. Catherine

      Perhaps it is a saving grace that the leaves are left to soak up the sun, and they are also delicious fresh, a wonderful garnish and salad leaf etc… 🙂

  5. Scott Wenzel

    Can you use 6-10-inch diameter clay tiles for blanching?

    1. Christy

      I’ve never tried it but I suppose you can. Keep an eye out for bruising or damage from sharp corners as the plant grows during that time.

  6. Judy

    Could you use PVC piping

    1. Christy

      I try to avoid plastics in the garden if possible, and just use newspaper. That said, I have seen people use 4″ PVC to elevate strawberries, so I imagine you could use it to blanch celery. The plant can get pretty wide, though, so make sure your PVC is big enough.

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