If you’re looking for a plant-it-and-forget-it perennial vegetable to grow, considering growing rhubarb (Rheum hybridum). It’s easy to grow rhubarb, and if planted in an appropriate space, this shade-tolerant, acid-loving plant can be counted on to provide years of prolific growth.
When growing rhubarb in your garden, it’s important to remember that not all parts of rhubarb are edible. In fact, rhubarb leaves contain oxalic acid, which can be quite toxic to humans and pets, so care should be taken when growing it.
When harvesting and preparing rhubarb, remember that the red stems are the only edible part. Although leaves should be harvested with the stems (and leaves should never just be stripped off of the stems unless those stems are being harvested), the leaves are not suitable for consumption. They can, however, be used to make rhubarb spray (a DIY insecticide) and lovely foliage displays.
Soil Conditions to Grow Rhubarb
Rhubarb can survive (and thrive) relatively maintenance free for 5-15 years, but first it needs to establish itself in a suitable environment for that to happen. Consider the following when deciding where to plant rhubarb:
- Rhubarb likes rich, fertile, slightly acidic soil.
- It can get quite large, easily covering a 3 ft by 6 ft area under optimal growing conditions. Be sure to give your rhubarb plants room to grow.
- How much sun rhubarb needs can vary based on your climate. Rhubarb tends to do best in cooler climates, so plant for full sun in mild climates and partial shade in hot climates.
- You can grow rhubarb in containers (and, in fact, if you’re looking for edible landscaping, rhubarb’s huge leaves and lovely colors can make a striking display), but you need to use huge pots for the plants to do well.
- Transplanting rhubarb multiple times doesn’t typically work well, so be sure to pick a good spot for it and then let it establish itself. If you’re planning on growing your rhubarb in containers, plant it in very big pots to begin with if you can rather than replanting it multiple times as it grows.
Tips for Growing Rhubarb
Although rhubarb seeds are available, most gardeners grow rhubarb from crowns or divisions because growing from seed can be much more challenging. Remember:
- Plants should be planted at least 24-36 inches apart.
- When planting rhubarb divisions, plant with the buds about 2 inches below the surface of the soil.
- When planting crowns, plant with budding tops of crowns about 1 inch below the surface.
- Plant in early spring or fall.
- Water well after planting, and keep the soil moist throughout the growing season.
- To help growing rhubarb establish itself, cut off flowering stalks. This will help conserve the plant’s energy and drive growth to the root system.
Harvesting rhubarb is pretty straightforward. To harvest, break off or cut stems 1-2 inches above the crown. If you don’t have a knife, just grab, twist and yank. Other than that, the biggest trick is just giving rhubarb time to establish itself. To do that:
- Let plants grow for at least one season (but preferably two) before harvesting.
- If harvesting the 2nd season, only harvest a few stems.
- Harvest lightly on the 3rd season, harvesting the stems for 4 or 5 weeks in the spring.
- After the 3rd season, you can harvest normally but never take more than half of a plant’s stems at a time.
- Finish harvesting by late summer to give your rhubarb plants time to recover and build up their energy stores for the following growing season.
- Although the leaves aren’t edible, they can be used in compost, to make rhubarb spray, and for mulch.
Division and Maintenance
Once established, rhubarb plants just need a little annual maintenance and occasional division to promote optimal future growth and health. This includes:
- Mulching every fall.
- Topping with compost every spring.
- Using a shovel to split the crown into 2-4 divisions when plants start to look crowded and/or under perform. Plant those buds about 2 inches below the surface of the soil, and care for as outlined in the rhubarb growing tips above.
And that’s about it. Because it doesn’t have many pest or disease issues, growing rhubarb is typically a pretty positive, hassle-free experience. For the most part, it’s all about finding the right spot for your rhubarb plants so that they can establish themselves.
Looking for more in-depth information on how to grow rhubarb (like preferred soil pH and planting depths)? Check out the Gardening Guides page for cultivating specifications for the most popular garden vegetables and other gardening resources.