By: Shelley Pierce
I must admit I have a rebellious gardening streak that makes an appearance every once in a while. You know – rebellious as in bucking good ol’ fashioned gardening advice because, well, just because. I was a bit sassy with my rhubarb this year. I let it flower. You read that right. I feel a lecture coming on. (sigh)
Yes, I do know that I compromised my rhubarb harvest by diverting energy into producing flowers and seed rather than actual edible stalks. But, hey, I enjoyed a splendid show of flowers and now have a rhubarb seed collection for planting more rhubarb next year! So, if you’re feeling rebellious, read on to learn more about how to collect rhubarb seeds and when to harvest seeds from rhubarb!
You could always obtain rhubarb plant seeds from your local seed supplier, but saving rhubarb seedpods from your garden is much more gratifying. However, you may or may not have the opportunity to harvest your own seeds because your rhubarb may not flower in any given year. The probability of flowering, or bolting in rhubarb, increases with certain varieties, the age of the plant, and the presence of certain environmental conditions and stressors such as heat and drought. Keep a close watch on the base of your rhubarb plant for the formation of tightly packed flower pods which, if left to fruition, will emerge into long stalks with unfurled flowers at the top. These flower pods can form at any point during the rhubarb growing season and can appear even in the early spring.
Rhubarb can be grown as a strictly ornamental plant and, after setting your eyes on the flower display, it’s easy to see why. You may at this point be tempted to cut the flower stalks prematurely and incorporate them into a flower bouquet, however, you will miss your opportunity for rhubarb seed collection.
Patience is a virtue here, as you will need to wait for a transformation to take place after the rhubarb has flowered before you harvest your rhubarb plant seeds. The flowers will turn into green seed and then eventually these seeds and the entire rhubarb branch (as a whole) will dry out and turn brown. This is when to harvest seeds from rhubarb.
Saving rhubarb seedpods is easy. Clip the stalks with snips or break the brittle branches off by hand. Hover the branches over a cookie sheet and run your fingers down the stalk, brushing the seeds onto the cookie sheet. Dry the seeds on the cookie sheet for a week or two, then package them up and put in a dark, cool place for storage.
It has been said that the shelf life of harvested rhubarb plant seeds does not extend past the second year, so this is something to keep in mind when planning your garden.
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|The ultimate guide to growing rhubarb in the UK|
What could be better than rounding off your Sunday lunch with a piping hot bowl of rhubarb crumble? Or how about a delicious rhubarb pie, summer fool or homemade jam?
Rhubarb is an undemanding perennial that’s easy to grow and fantastically hardy. In fact, it actually needs a cold snap in order to produce the best crops.
A healthy rhubarb plant will remain productive for at least 10 years so it makes an excellent investment. During the first year, you’ll need to resist the temptation to harvest the stems. But from the second year, you can harvest your rhubarb from April to June. Here are some tips on when to plant rhubarb and how to grow your own..
Rhubarb plants may be started from seed. Plants started from seed typically take 2 years to get a harvest, although in the proper climate one can get satisfactory results in one growing season. Also, propagation of rhubarb from seed is not recommended, as rhubarb seedlings do not retain the characteristics of the parent plants (see comments on Varieties). It is best to propagate with planting divisions obtained from splitting the crowns as described in the next section.
Step by Step: Growing Rhubarb from seeds
Rhubarb seeds can be purchased mail order from a number of companies (see Sources). The seeds are encased in a rather large paper-like shell. Soak the seeds in water for a few hours before planting. Plant the seeds in a suitable planting mixture. These seeds were sown in a commercially available mixture, 2 seeds per pot. I planted them in peat pots to making transplanting them easier and then put them in a sunny window. A heating cable will help speed the germination if the room temperature is below 70 degrees F.
Rhubarb seeds germinate quickly. Shown here is a tiny rhubarb seedling at 10 days after planting (March 1997). At this point I will pinch off all but one seedling (I planted 2 seeds per pot, expecting the germination rater to be 50%). If I had wanted to grow these as annuals I would have started them sooner, like in the fall of the previous year, so I could plant them outside in early April.
As the weather turned warmer (45 degrees F during the day, near 32 degrees F at night) I transplanted the rhubarb seedlings outdoors. I planted them in a mixture of 50% compost and 50% garden soil.
Protect the seedlings from the bright sun. Rather than harden off the seedlings by gradually increasing their exposure to sunlight, I fitted the rhubarb plants with tiny little paper hats. These only lasted for about a week but that was long enough.
Shown here is the same seeding shown above but in 60 day since planting (30 days after being transplanted outside). The plant is finally beginning to look like a rhubarb plant. At the end of the growing season these plants were about 12 inches () tall and had about 15 leaves each. Not quite enough for a harvest. Next year maybe.
The rhubarb plant is a beautifully colored and tart stem that often makes delicious pies or jams. It is a cool season plant and grows as a perennial, meaning it comes back every year. It is drought resistant, and sometimes it is grown for its foliage to be used as a border. Rhubarb is actually considered to be a vegetable, though many think that it is a fruit.
Plant rhubarb crowns that are 1 year old in the spring as soon as the ground can be worked when the roots are still dormant and no new growth has begun. You can also plant rhubarb in the fall once dormancy sets in. When planting, space the plants 4 inches apart with the roots 1 or 2 inches below the soil line. Prior to planting, amend the soil with compost and manure to aid in growth.
Rhubarb grows best in well-drained, fertile soil and in full sun. Mulch the plants heavily with straw or manure to deter weeds, retain moisture and continue to provide nutrients to the soil. Split the rhubarb plants every three to four years, as this will help continue good growth. Divide the plants when they are dormant in the spring. Rhubarb plants require plenty of water. If you don’t think you are watering the plants enough, dig into the soil nearby the plants. Soil should be moist up to 4 inches deep. If it is soggy, refrain from watering for a few days until it dries out.
Rhubarb plants aren’t ready to harvest until their second season of growth, because this is when they have become established. Stalks are ready to harvest when they are 12 to 18 inches in length. The harvest period will run up to 10 weeks once the plants are 3 years old. To harvest, grab the stalk at its base and pull and twist it away from the ground. You can also cut the stalk at the base. Discard the leaves after harvesting. If stalks are too slender do not harvest them.
Rhubarb plants are heavy feeders. Apply a 25-3-3 or 10-6-4 high nitrogen fertilizer when the ground thaws in the spring. This is a good time to fertilize because the fertilizer will go into the ground but won’t harm the roots. If using a granular fertilizer, apply one-and-a-half pounds per 100 square feet of rhubarb plants. If you prefer to grow organically, mix compost and manure into the soil instead of a chemical fertilizer.
You can fine rhubarb seeds and crowns at Urban Farmer.
Rhubarb stalks will be ready for harvest about 90 days after plants begin growing in spring. Here are popular varieties to grow: