How to Grow Rhubarb
by Roy Beck
Rhubarb is a plant that I have been in love with for a long
time. This hardy perennial deserves a permanent place of honor in every kitchen
garden. Though technically a vegetable, it is used as a fruit—in pies, cakes,
preserves and other sweet dishes. Rhubarb is not difficult to grow and enjoy if
its needs are met.
Rhubarb likes to grow in full sun or light shade, in a rich
sandy loam soil that drains well. Most rhubarb is propagated by division, not by
seed, because the seed is not always true to type.
Some books suggest that the division be planted so that its
growing tips (buds) are four to five inches below the surface of the soil. Here in the
Pacific Northwest where I live, with all the rain that we get, the plants would rot if they
were planted that low in the ground. For this reason, I prefer to mound the soil
about six inches high and plant the plants so the buds are just below the soil
surface. For those of you who live where it is drier and colder, the plants
could be planted lower in the ground.
I plant rhubarb divisions three to four feet apart and water them
well after planting. The plants need to be kept moist, but not too wet or too
dry. If they dry out, they will go dormant, and if they are over-watered, they
Rhubarb is a heavy feeder, and I find that composted manure
is the best fertilizer for it. Do not use fresh manure as this can burn the
plants. Each year, just before winter comes, I fertilize the plant with three to
four inches of manure compost. If the plants are fertilized too soon in the fall,
they will start to grow again and will not be dormant when winter sets in. Over
the winter, the compost will be decomposing and will be broken down by the time
you are ready to pick the first rhubarb stalks in the spring.
Rhubarb is a plant that usually does not have much trouble
with diseases and pests. I remove and compost dead leaves and stalks because
diseases can overwinter in them. I don’t put composted rhubarb plants back on
the rhubarb patch.
Only the leaf stalks (petioles), which can be pink or red or
even green, can be eaten. Rhubarb leaves are poisonous to humans and livestock
and should never be eaten.
For the first year after planting your rhubarb plant, don’t
pick any stalks. This will allow the plant to focus its energy on developing a
strong root system. The following year, you can harvest some stalks. The plants
will come into full production in the third year and continue for many years if
Commercial growers go through the fields and cut off all the
stalks each time they pick. I do not think this is the right way to pick
rhubarb. Weakening and stressing the plants in this way encourages them to go to
seed. Seed production uses up a lot of energy that could be used to grow stalks.
As with pruning any plant, one should not remove more than a third of the plant
at any given time. If you pick only those stalks that are of mature size and
fully-grown and let the others continue growing, you can extend the rhubarb
harvest over a longer period.
When the stalks start becoming very thin in diameter, it is
time to stop picking. Also, as it gets warmer and later into the season, the
rhubarb generally will not be as good to eat because it will get stronger in
flavour and will have more fibres. There are, however, varieties in Sweden that
have high-quality, low-acid stalks that can be picked all season long.
Rhubarb does not grow well when the temperature rises above
80º F and the soil dries out. But if you keep the plants well watered (not over
watered) and do not over-pick the plants, they should keep growing all summer.
The big rhubarb leaves are very good at cooling the soil, keeping it moist and
shading out weeds. If a mulch is to be used, very well composted manure is the
When the rhubarb plants are 3 to 4 years old, they can be
divided. If rhubarb plants are not divided in about 10 to 15 years, most
varieties can lose their vigor and slow down—and possibly die.
Rhubarb should be divided when it is dormant—before the
ground is frozen in the fall or after the ground has thawed in the spring. With
a shovel, I remove either the whole crown or part of the crown from the rest of
the rhubarb plant. I then divide it into pieces at least the size of a
doubled-up fist. Smaller pieces might grow, but the larger the pieces are, the
more energy they will have to get a good start. Smaller pieces take a lot of
care, so I start with a large division.
Roy Beck’s Rhubarb Crisp
3 cups brown sugar
2 cups all-purpose flour
2 cups old fashion oats
¾ cup softened margarine or butter
2-¼ pounds chopped rhubarb
In a large bowl, mix the brown
sugar, flour, oats, and butter together. Heat oven to 375°F. Use an oval pan, 12"×11"×2". Make a layer of the sugar, flour, oats, and butter mixture into a
crust on the bottom and sides of the pan. After filling the pan with the
rhubarb put the rest of the mixture over the rhubarb. Bake for 40 to 50
minutes or until the rhubarb is tender. Serve warm with vanilla ice
cream or whipped cream.
Commercial plant growers dig the rhubarb divisions when the
rhubarb is dormant and store them in a cooler until spring to sell them. Here in
the northwest, rhubarb can be planted in either spring or fall. If you are in a
colder climate you will need to wait until you can work the soil.
After picking the rhubarb, wipe the stalks with a moist cloth
to clean them. If you put the stalks into water to wash them, they will split
before storage, so just wash prior to use.
Clean rhubarb should be stored in a cool dry place like a
refrigerator. If the stalks are fully mature when they are picked, they will
keep very well for a couple of days. But if they are picked immature, they will
wilt and not be useable.
Rhubarb can also be stored in the freezer and used throughout the year. Cut
the stalks into one- or two-inch pieces and put them into airtight freezer
containers. Then place the containers in the freezer and enjoy them as needed in
your favorite rhubarb recipes, such as my rhubarb crisp in the sidebar.
I have been growing plants all of my life. As a child I spent
a lot of time in our garden and helped my neighbor with his garden. I have
always loved to watch plants grow and have wanted to learn more about how this
great thing could happen. I spent four years at community college studying
horticulture and landscaping. I did landscaping for ten years and then went on
to do other things. Later, after my wife and I got married, we moved to the
Vashon Island so that we could have a place to have our plants and animals. For
the last nine years, we have been selling organic vegetables and fruits at the
local farmers’ market. As the farm grew, we came to the point that it needed be
certified organic. So for the past four years the Washington State Department of
Agriculture has certified us organic. We are members of Washington Tilth, an
organization that promotes the production of organic products.
I have been collecting rhubarb and now have some 90 different
varieties. I started to look for rhubarb plants and found that the books listed
a lot of different varieties that were not to be found. So like all the other
vegetables, rhubarb varieties are disappearing and need to be saved. I need your
help in finding the varieties of rhubarb. I know that there are varieties out
there that I do not have in the collection because I have read about them. The
variety of rhubarb that you have or see might be one that I do not have and that
needs to be saved. Please pass on to me any information that you have about any
varieties of rhubarb. If the variety is one that I do not have, I could either
buy it or trade with you for one that I have. I hope to be able to keep adding
to the collection for many years to come.
Roy Beck grows 90 different varieties of
rhubarb. He is interested in saving rhubarb varieties from disappearance and
invites readers with a similar interest to contact him at