Rhubarb can make a delicious pie, and it is not too picky about growing conditions when established. However, there are a few things to remember if you want to help your rhubarb thrive after planting.
So, where should you plant rhubarb? Plant rhubarb in fertile soil that is acidic to neutral soil (pH of 5.0 to 6.8). Loamy soil is better than clay or sand. To improve drainage, plant rhubarb in a mound or raised bed. Rhubarb prefers full sun, but it can tolerate partial shade (it needs 5 to 6 hours of direct sunlight per day).
Of course, rhubarb will tolerate drought when established, and it is not too sensitive to soil pH.
In this article, we’ll take a closer look at what conditions rhubarb needs for optimal growth.
Let’s get started.
Where To Plant Rhubarb?
Rhubarb (Rheum rhabarbarum) is a perennial in the buckwheat family. The ideal location for planting rhubarb has the following:
- Lots of nutrients (rhubarb is a heavy feeder, so it needs fertile soil).
- Acidic soil pH (rhubarb will tolerate a soil pH range of 5.0 to 6.8).
- Loamy soil (rhubarb will not perform as well in clay or sandy soil).
- Raised elevation (this helps to improve drainage, especially in clay soil).
- Full sun or partial shade (rhubarb needs at least 5 to 6 hours of sun per day).
Fertilizer & Nutrients For Rhubarb
Rhubarb is a heavy feeder, and it may benefit from fertilizer (especially in light soil). The Iowa State University Extension suggests adding half a cup of balanced all-purpose fertilizer (such as 10-10-10) around each plant and working it into the soil.
(If you aren’t sure what 10-10-10 means and want to learn more, check out my article on fertilizer numbers here).
Avoid getting fertilizer on the crowns – you don’t want to burn the plant itself! Rather, you want the fertilizer to send nutrients into the soil around the plant for the roots to absorb throughout the growing season.
Soil pH For Rhubarb
Rhubarb is not very sensitive to soil pH, and it will grow in a wide range of soil acidity. In fact, the University of Maine suggests that rhubarb can tolerate acidic soil with a pH as low as 5.0.
However, the Old Farmer’s Almanac suggests that the ideal soil pH range for rhubarb is 6.0 to 7.0 (slightly acidic to neutral). This is what most other plants prefer as well, so rhubarb will fit in well with the other plants in your garden without needing an extreme soil pH.
If you aren’t sure about your soil pH, you can learn how to do a soil test or adjust soil pH in my article here.
Soil Consistency For Rhubarb
Rhubarb is susceptible to diseases when the soil stays too wet for too long, so it needs well-draining soil. It also needs fertile soil with plenty of nutrients, since it is a heavy feeder.
- Clay soil has small, fine particles that retain water. As a result, it drains slowly, and the resulting wet soil encourages diseases such as Phytophthora root and crown rot.
- Sandy soil drains fast, but nutrients tend to drain away with the water. Since rhubarb is a heavy feeder, sandy soil makes it difficult for the plant to get enough nutrients.
Adding compost is always a good idea. It will add nutrients and organic material to your soil, which attracts beneficial organisms (such as bacteria and earthworms).
Adding compost also helps with moisture levels. Compost will make clay soil drain better, but will help sandy soil to retain a little more moisture.
Compost is great for “balancing” out your soil, and it is a good first step before you use other types of fertilizer or amendments. You can learn about how to make compost in my article here.
Elevation For Rhubarb
Maybe your entire garden consists of heavy clay soil that never drains. Or maybe the rainy season is merciless in dumping several inches of water over your yard all at once.
Don’t worry – there is a solution! Mound up some soil and plant the rhubarb on the mound to improve drainage.
This method is easy and doesn’t require you to build anything. However, if you like to build things, there is another way to elevate rhubarb to improve drainage.
A second option is to plant rhubarb in a raised bed, which will also drain faster than the soil in the ground. You can find some interesting ideas for raised beds here.
If you are worried about a wooden raised bed rotting, check out my article here for ideas to preserve the wood or alternatives.
Sunlight For Rhubarb
Rhubarb prefers a location with full sun, where it can get at least 5 or 6 hours of direct sunlight per day. It can tolerate partial shade during the day – and this may even be preferable in extremely hot locations.
Rhubarb is a cool weather crop, and it needs cold in the winter. The Old Farmer’s Almanac suggests that it is hardy in USDA Zones 3 to 8 (you can find your USDA hardiness zone with this map).
How Many Hours Of Sun Does Rhubarb Need?
Rhubarb will grow better with full sun. However, it has giant leaves at the end of its stalks for a reason!
With a dozen or more of these stalks with huge leaves, rhubarb can make the most of the sunlight that reaches it – even in partial shade. According to the University of Nebraska-Lincoln Extension:
“Rhubarb performs robustly in a location where it gets sun all day but will still do OK in a location where it gets a minimum of 6 hours of direct sunlight each day.”https://extension.unl.edu/statewide/thurston/rhubarb/
So, if rhubarb has a tall tree or shrub to one side of it, it can still get enough sunlight during part of the day to survive and even thrive.
Does Rhubarb Grow In Shade?
According to the Old Farmer’s Almanac, rhubarb does tolerate partial shade. However, it won’t do well in full shade.
You can create more rhubarb plants from your existing plant, but the seeds may not always give you a plant that is similar to the parent plant.
Instead, the Oregon State University recommends crown division to propagate rhubarb. This will often occur 5 to 6 years after planting.
One sign that it may be time to divide the plant is when you start getting smaller and thinner but more numerous stalks (1.5 to 2 times as many as you used to get).
The best time to divide the crown is when the plant is dormant, usually in spring so that new plants can survive winter. You will need to dig up the plant before you can propagate by dividing the crown.
Each piece that you cut from the crown should have at least one large bud. You can get 8 to 10 divisions from one crown that is mature (5 to 6 years old).
When planting the divided pieces, dig a 10 to 14 inch hole for the new rhubarb plant. Bury the crown so that the buds are only 2 inches below the soil surface.
Leave 3 to 4 feet between rhubarb plants and 3 to 4 feet between rows. This will allow enough space for walking the rows and caring for the plants.
Now you know where to plant rhubarb and how to prepare your garden soil for this sour but satisfying plant.
You might also want to read my article on how big rhubarb plants get.
I hope you found this article helpful. If so, please share it with someone who can use the information.