Rhubarb is an easy growing, cool-season vegetable that should have a spot in every home garden. Despite being used in countless desserts, rhubarb is actually a vegetable and this hardy perennial will give you several harvests each year.

But, before you take your pickers and head to the garden, it’s important to know when to pick rhubarb for the best flavor and fruit quality and how harvest stalks properly, so they will return year after year.

The best time to harvest rhubarb plant is when stalks reaches 12 and 18 inches (30 and 46 cm) long and ¹⁄₂ and 1 inch (1.3 and 2.5 cm) wide, and ripe rhubarb can be harvested from early spring until mid-July. To harvest, pulling out the stalks instead of cutting them will make the rhubarb plant healthier and more productive.

Rhubarb is as easy to harvest as it is to grow. In this article, we will discuss how to tell when your rhubarb is ripe, and how to pick stalks from a rhubarb plant for a continuous harvest.

What Parts Of Rhubarb Can I Eat?

The rhubarb’s petiole (or stalk) is a sour, edible vegetable. You should not eat the leaves, as they contain high amounts of oxalic acid, which can lead to vomiting, diarrhea, and ultimately kidney failure.

Oxalic acid is actually found in all parts of the plant, including the stalks, and this is where the sour taste comes from.

Yet the amount of rhubarb you consume would have to be very high to cause issues. Here is a link to an article that discusses further health concerns of eating rhubarb leaves.

Does rhubarb become poisonous in the fall? Many of us grew up being told that after the summer, rhubarb becomes poisonous.

An old tradition, it is based on the belief that oxalic acid will increase during the summer. It is probably untrue, and I have eaten rhubarb from my garden in August with no ill effects.

Some evidence suggests, however, that oxalic acid might transfer to the stalks when rhubarb leaves wilt or become frosted

Is It Possible To Harvest Rhubarb In Its First Season?

Depending on what method you used to start your rhubarb, the answer to this question may vary. Root cuttings, bare root plants, potted plants, or seeds can be used to grow rhubarb, and each takes a different amount of time to establish itself before it can be harvested.

Root Cutting: Growing rhubarb from a root, or crown, cutting is the most common and fastest way to start your rhubarb. A chunk of a plant’s root is simply cut off, and the new crowns are usually planted in the fall or early spring. First year harvests usually yield a light crop.
Bare Root or Nursery Stock: The nursery may also have bare roots or small pots of rhubarb that you can buy. It is not recommended to harvest either of these in the first year. The second year, they can be harvested lightly and as usual each year thereafter.
Seeds: Starting rhubarb from seed usually takes 2 to 3 years before it is large enough to harvest.

When Is The Best Month To Harvest Rhubarb?

Harvest your rhubarb from early spring until mid-July. After this, its growth and quality are reduced, and rhubarb stalks will wilt and rot quickly in the heat.

During its peak growth in the spring and early summer, there are several different ways to harvest your rhubarb.

Pick stalks as needed: Harvest stalks of the plant during the growing season as you need them for your cooking or baking. This will also help thin out the plant and prevent some of the larger stalks from over-maturing.
Harvest the first crop: Rhubarb is likely to be ready for a large harvest in mid to late spring. Leave a few of the small stalks and leaves on the plant and the plants can regrow more quickly if this is done.
Harvest the second crop: New leaves will shoot up just a few days after your first harvest. The rhubarb will have regrown enough by early summer for a second harvest. Leave no leaves behind this time. Despite slow regrowth over the summer and fall, the plant will still produce enough foliage to protect it over winter.

You might be lucky enough to get a third harvest before summer hits. Our zone 2b climate allows us to pick stalks in late May and our first harvest is generally mid-June, then the second harvest is early to mid-July.

What Time Of Day Rhubarb Be Harvested?

For the best results, rhubarb should be harvested in the morning. On cool nights, the plants take up water and use starches to create sugar which is still in the plant in the morning.

Due to its thick leaves and tough stalks, rhubarb plants are less likely to wilt from the heat than some of your garden’s more delicate vegetables. When harvesting during the summer, keep the newly picked stalks shaded to keep them from drying out.

How Much Does A Rhubarb Plant Produce?

Your rhubarb plant’s yield will differ greatly by variety, growing conditions, and climate. According to most online references, you should plant 2 to 3 plants per person, and each plant’s yield should range between 1 kilogram and 3 kilograms (2-6 pounds).

We get upwards of 10kg per harvest (22lbs) from our garden, so one plant is more than enough for us.

How To Tell If Rhubarb Is Ready To Pick?

Rhubarb stalks’ sizes are the best indication of when when rhubarb is ripe ready to harvest.

You can tell if your rhubarb is ready to pick or not by checking the following:

Choose the best size: At harvest, rhubarb stalks should be about 30cm (12 inches) long and about 1.25 cm to 2.5 cm (1/2 to 1 inch) in diameter. In spite of this, we have harvested them much smaller (these are best eaten raw) and some more than a meter long.
Don’t rely on color: Color does not indicate rhubarb ripeness. The color is determined by the variety of rhubarb you are growing. Depending on the variety, rhubarb can be green, deep red, or red/green.
Wait until there are enough stalks: You should wait until the plant has at least ten stalks before harvesting or the plant’s regrowth will be delayed. It’s especially important if for young plants or if it’s still very early in the season.

Do Rhubarb Flowers Affect Harvest?

You can probably expect your rhubarb plant to produce flowers and go to seed at some point. Summer is usually when rhubarb flowers, but late spring is often when it begins to send up flower stalks.

The stalks of the flowers themselves are inedible and woody, but you can still get a fine harvest from the remainder of the stalks.

As soon as a flower blooms, all of the plant’s energy is spent on producing seeds. In order to promote new stalk growth, it is best to remove blossom buds early in the season.

As soon as your harvest is completed, you can either leave the buds to go to seed or remove them. It has been equally successful to remove or leave the buds.

How to Harvest Rhubarb the Right Way

Rhubarb is easily harvested by hand. Here are some simple steps for picking rhubarb.

Start with the biggest stalks first. Then move on to the smaller ones.
As a general rule, leave about 1/3 of the stalks still on the plant.
Firmly grasp the stalk as close to the base as possible. Most stalks will come out with a gentle tug.
If the stalks is stubborn, twist the stalk while pulling it. Sometimes you really have to pull hard to get it out.
Stalks are better removed by twisting than by cutting. Twisting off the stalks can encourage new leaves to grow while cutting them leaves a stub that quickly rots.
Remove the leaves by twisting or cutting them off. You can twist them off by grasping the stalk with both hands just below the leaf and twisting while pulling your hands apart. Alternatively, you may want to try cutting it off with garden shears or a sharp knife.
Add the leaves to your compost bin or mulch your garden with the larger ones to shield the soil and choke out weeds.
When you twist off the stalk, there will sometimes be a small bulb at the base. Twist or cut this off and add it to the compost bin.
After you finish harvesting in July, this is a good time to add some compost. Now you can let the plant rest and recover for the remainder of the summer.
Of course, you can still sneak out a few leaves if you need them over the summer and into the fall.

Storing And Preserving Your Rhubarb Harvest

In addition to storing very well, rhubarb also preserves well. You can keep your harvest in the following ways:

In the fridge: In your refrigerator, fresh rhubarb will last two to four weeks. The stalks should be left unwashed (or properly dried) and whole if possible.
Frozen: Rhubarb should be cut into 1 cm (1/2 inch) wide pieces. They should be frozen on a cookie sheet before being put into an air-tight container. Unless it becomes icy or freezer burnt, frozen rhubarb will last for about a year.
Dehydrated: You can dehydrate the rhubarb by cutting it into pieces about 1 cm (5/8 inch) wide and following the instructions for your dehydrator. You can also dehydrate them in the oven. Rhubarb can be stored for about a year in an airtight jar.
Canned: Rhubarb can be canned in a few different ways, and many delicious recipes can be made. Follow the directions on your canner carefully.

Conclusion

Many rhubarb plants will produce for over 20 years. It is important to know when and how to harvest this perennial so you can enjoy it year after year.

I hope this article has given you enough information so you can make the most of your prolific rhubarb plant.

Now it is time to buy a lot of sugar and get baking!

Written By

Amber Noyes

Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.

9 Comments

Carole Elsner says:

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Love all the explanations. I have always pulled the stalks, but saw someone cut them and wondered which was the best way. Thanks!

1. Amber Noyes says:
  
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  Don’t cut those rhubarb stalks! it’s a bad idea. When stalks are sliced with a knife, the part left behind withers away.
  
Kw says:

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I have a ton left still and it is September, is it ok to eat those or are the toxi s to high?

1. Amber Noyes says:
  
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  You can harvest rhubarb in September and it is useable if a little less tender than in the spring, but they don’t become become toxic or poisonous. If you’re craving some rhubarb go ahead and cut a few stalks.
  
Terry says:

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Hi,I have planted a rhubarb crown in spring this year,all the advice is not to harvest in the first year.My question what do I do with the stalks the plant has produced this year ?

KJ says:

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we have a terrible grasshopper problem. How to remedy???

1. Amber Noyes says:
  
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  Grasshoppers hate the smell of cayenne pepper, garlic, and onion. Mixing both substances with water and making a spray is the greenest solution you can make.
  
Sandylee says:

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Thank you for the info. I am never sure when to harvest

Kathy says:

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My experience has been that rhubarb cut into 1/2 inch pieces for freezing separates from it’s moisture when thawed. Instead, I cut the stalks into longer pieces, usually about 6-8 inches or more, depending on width of the bag I am freezing in. Then, just before I am ready to add the rhubarb to a recipe, such as a cake, I cut it into the 1/2 inch pieces (or less) while it is still just thawed enough to slice easily. This keeps the moisture in each piece and bakes like fresh harvested rhubarb.