Growing rhubarb can be one of the easiest things to grow in the home garden. Because it grows in a wide range of garden zones, this low maintenance plant can give you many, many years of harvests.
Rhubarb is a perennial vegetable that does well in garden zones 3 to 8. It is even considered an early spring harvester in Alaska! That being said, rhubarb can be grown from seed as an annual in zone 9.
Growing Conditions for Rhubarb
Rhubarb plants are adaptable, large plants that will grow in a variety of climates and soil conditions. However, like all plants it will grow best when given the right conditions.
- Full Sun – Rhubarb prefers full sun, although it can do well in partial shade too.
- Well-Drained Soil – Be sure the ground is not soggy. New plants need to be watered well, but the soil needs good drainage so they don’t get root rot.
- Fertile Soil – Like all edible perennials, rhubarb plans are heavy feeders. Make sure there is plenty of organic matter in the soil and add a thick layer of compost each fall.
- Spacing – Given the right conditions, rhubarb plants can grow up to 4 feet wide and tall, and live for 20 years. So, be sure to plant them where they have room to grow.
Growing Rhubarb from Seed
It is possible to plant rhubarb from seed, but you will typically need to wait until at least their third year of growing before you get your first harvest. That being said, if you are growing rhubarb in a warmer climate as an annual, it’s a good idea to grow rhubarb from seed as it’s much more cost effective.
If you already grow rhubarb and want to inexpensively expand your patch, saving seeds from your own plants is a great option. Just know that the new plants will not be identical to the parent plants. Like most perennials, rhubarb doesn’t grow true to seed, which is not necessarily a bad thing. However, unlike a plant like apples, rhubarb grown from seeds will be very similar to the rhubarb the seeds were collected from. So, there’s very little risk involved in saving your own rhubarb seed to grow.
If you need to buy seeds, “Victoria Rhubarb” is an open-pollinated heirloom variety and is not overly stringy. We highly recommend MI Gardener for your seeds. Because it’s a heirloom plant and not a hybrid, they will grow true to seed.
In colder climates (gardening zones 3-8), start seeds indoors 8-10 weeks before your average last frost date. Keep seedlings moist but not over wet to avoid root rot. Be prepared to transplant seedlings about 2 weeks before your average last frost as can handle a bit of frost. Harden off plants by putting them outside during the day and on warmer night before planting them outside.
In zone 9 start rhubarb seeds in August to grow over winter, keeping the soil moist but not overly wet. Transplant the seedlings when the plants are about 4-inches tall and have 3-5 leaves. This should be in late September or early October as rhubarb is a cool-season crop.
Planting Rhubarb Plants
The easiest way to add rhubarb to your garden is by dividing mature plants. As rhubarb gets older, diving the plants will help ensure stalks stay thick. Divide the rhubarb crowns at the beginning of spring, just as new growth is starting to form. Use a clean, sharp shovel to divide the plant, typically in half or thirds for larger established plants. Just ensure each section has at least two stalks. This can also be done in late fall, after the plant has gone dormant, but spring is the best time to divide rhubarb plants.
If you don’t have a rhubarb patch to divide, your local garden center will sell rhubarb crowns and sometimes plants for easy transplanting. These can be planted as soon as the soil is workable in the spring.
Divided plants and transplants can be harvested on their second year. This will allow the young plants to grow a good root system.
Rhubarb Crown Varieties
The different varieties of rhubarb have different intensities of red and fibrous stalks, as well as sizes. It’s probably best to ask someone who is growing rhubarb in your area, which variety does best. Rhubarb, especially when you need to buy crowns, is a commitment of time and money.
“Crimson Red” rhubarb stalks grow up to 36″ long and are typically not stringy.
“Canada Red” is often considered sweeter and is a smaller plant. The stalks are a bright ruby red.
“Crimson Cherry Rhubarb” has deep red stalks and is said to grow in garden zones 2 through 9.
“MacDonald Rhubarb” is resistant to crown rot and has a partial red/ green stalk.
“Valentine Rhubarb” has bright red stalks and typically has very few to no flower (seed) stalks.
Growing Rhubarb
Once you have the planting area picked out for growing rhubarb, remove any weeds and add plenty of well-rotted manure or some compost to the site. Rhubarb also likes potassium, so sprinkle a little cooled wood ash on the soil and mix in.
Once rhubarb seedlings are planted in the garden, it’s incredibly easy to care for. Rhubarb has large leaves which means it does fairly well at keeping the weeds at bay. Although you should help it along with this task for the first year or two after planting.
Organic mulch is a good option for rhubarb plants. Just remember you do not want the soil around it to be soggy or it will rot.
Warmer climates may need to water their plants on a regular basis especially in the hottest months, but areas like the Pacific Northwest typically have enough rain to take care of it. Check the soil moisture often and water when the top inch of soil is dry.
There are few pests that will mess with rhubarb, partly due to the leaves containing large amounts of oxalic acid. This also makes them fairly deer and moose resistant! Rhubarb curculio is a beetle that you will need to keep an eye out for. Either remove them by hand or try sprinkling diatomaceous earth around the plants. Any mites that occur should be treated with neem oil.
Rhubarb will die back in late autumn, but the crowns are still alive, they’re just dormant. There is no need to cover it for the winter, it needs the cold temperature to trigger spring growth.
In late winter, sprinkle wood ash and compost on the soil surface, making sure to not disturb (dig up) the crowns.
Harvesting Rhubarb
Rhubarb stalks ( sometimes called rhubarb stems) are the ONLY edible part of the rhubarb plants. This is the part that grows up from the base of the plant and has a leaf on it.
The growing season for rhubarb is from early spring to late summer. Harvesting can happen whenever the leaf stalks are long enough, this is usually in late spring. The optimal length will depend on the variety – it will be anywhere from 10-inches to 24-inches long.
Harvesting rhubarb is extremely easy. Once the leaf stalks are at least 10-inches long (longer for some varieties), grasp at the base and pull sideways. This will remove the entire stalk from the base of the plant. Some gardeners prefer to use a sharp knife to harvest, but this is not necessary and can possibly carry disease from one plant to another.
Use a clean knife to cut the leaf off the rhubarb stem and the base of the stalk that widens out at the crown. You can use the leaves as chop and drop mulch for the rhubarb patch or add them to your compost pile. Just remember that the leaves are poisonous and should not be fed to people or animals.
You can either snack on the rhubarb right away (I grew up watching my dad walk around the yard with a stalk of rhubarb in his mouth) or it can be stored in the refrigerator for up to two weeks.
If you wish to get several harvests from your rhubarb plant, be sure to remove the flower stems when they first appear. These often reach up to 5 feet tall and produce white/ pink flowers, almost like cauliflower in shape. Simply pull the stalk away from the crown at the base to keep your plant producing edible stalks. You can, of course, leave the flower stalks to add some prettiness to your garden and save the seeds once you have enough rhubarb harvested.
The rhubarb growth will slow down in early summer. Once you’ve harvested all you need, let the plant keep all of it’s leaves to build it’s reserves for the following year.
But what if I have green rhubarb? When is my rhubarb ripe?
Some rhubarb varieties produce more green stalks than others, this is especially true if you’re growing rhubarb as an annual in a warm climate.
This doesn’t mean it isn’t ripe though. As long as the stalks are at least 10″ long and 3/4″ wide, you can eat them. Leave at least two stalks on the plant when you harvest to ensure the plant still has plenty of reserves. When you are done harvesting for the season, usually around mid to the end of June, let the remaining leaves stay to build up energy for the winter.
Preserving and Using Rhubarb
Due to its tart flavor, rhubarb is typically used in sweet desserts, such as Rhubarb Crisp or Rhubarb Pie. It is also easily preserved for later use. Slice and freeze fresh rhubarb by simply placing it in a freezer bag. This is best when you plan on making rhubarb juice, as freezing gives you more juice.
Canning it for other uses is a great way to preserve it as well. Give it a twist and make some Low Sugar Balsamic Strawberry Rhubarb Jam or Easy Rhubarb Relish
Here are more rhubarb recipes to make the most of rhubarb season!
