Weedy Rhubarb Stalks

Dear Lynn

My rhubarb stalks are all weedy - the stalks earlier in the year were slightly better but not strong thick stalks.

What should I be doing now to ensure that my rhubarb patch grows more strongly for next year - I have two crowns which are in their 3rd year and two newly planted this year.


Sue  - Northumberland

Dear Sue,

Firstly I’ll give you some general advice which is important as it affects the productiveness of your rhubarb in the years to come.

  1. Rhubarb needs an open, sunny site with moist, but free-draining soil - it hates being waterlogged in winter and stems are susceptible to frost.
  2. After planting rhubarb, it's best to wait 2 years (growing seasons) before harvesting any stalks (if you can!). The two-year establishment period allows the plants to become strong and productive.
  3. Rhubarb can be harvested over a 4-week period in the third year. In the fourth and succeeding years, stalks can be harvested for 8 to 10 weeks.
  4. Keep rhubarb free of weeds by covering the ground with a mulch of composted manure, but avoid burying the crown as it will rot. Cover the area above the roots with 100g per sq.m of Growmore or other general purpose fertiliser in March and water regularly in dry spells to keep it moist and actively growing until autumn.
  5. You should stop harvesting well-established rhubarb plants by mid-June. Continued harvest through the summer months weakens the rhubarb plants and reduces the yield and quality of next year's crop. The rhubarb stalks do become woody by mid-summer.
  6. When the top growth dies back in autumn, remove the dead leaves to expose the crown to frost - this will help break dormancy and ensure a good crop of stalks the following year.
  7. To get an earlier crop, you can force the stems by covering the crown with a traditional forcing jar, bucket or upturned pot in late winter, ensuring that all light is deprived (make sure to cover drainage holes in pots with a brick or a stone).  When stems reach the top of the container, they are ready for harvesting. Forced stems are lighter and more tender than those grown in the light, and are generally ready three weeks earlier.

Crowns often lose vigour when they are older plants and need dividing but your plants are still fairly young so I'm not suggesting you do this with your plants.

I would suggest that you leave your 2 year old plants to grow next year and conserve energy without harvesting any stalks. Hopefully if you follow the advice the more established plants will reward you with some nice big tasty stems.

Take a look at these Terracotta Rhubarb Forcers on the Harrod’s website; Small Terracotta Rhubarb Forcer & Large Lightweight Rhubarb Forcer.

These Blanching Cloches can be used as rhubarb forcers too (as long as you exclude the light at the top), they are a cheaper alternative to the terracotta forcers.

Good luck with your rhubarb crop next year – if you remember please let me know how you got on.

Kind Regards

Lynn Burton
Horticultural Adviser