Beginners Guide to Growing Rhubarb Crowns or Seeds

Keep your rhubarb crown watered, especially if the weather is dry.  It is important to weed regularly and mulch with well-rotted manure or garden compost.  This is needed both in the first years to help it establish, and annually in Autumn to keep it growing well. Make sure you don't cover the crown as it may rot if you do.  

In early Spring, feed with a general purpose fertiliser according to the pack instructions.

The leaves will die back in Autumn as the crown becomes dormant again.  When this happens, remove the dead leaves and compost them.  This will reduce the likelihood that fungal spores will take hold over winter and will also expose the crown to frost which will help break dormancy and promote a good crop next year.  With a little bit of attention, rhubarb plants should last a good 10 years.  

Forcing Rhubarb

This is not something for the first two years but you might want to do this once your plant is fully established.  This is when you trick the plant and 'force' it to provide a crop around 3 to 4 weeks earlier.  You may not think this is a timeframe worth the effort, but when you consider there is virtually no other fruit coming out of the garden in March then why not give it a try?    

How to Force Rhubarb

To force rhubarb, you need to exclude light from the plant in late winter.  There is a specific bit of kit for this known as a forcing jar - traditionally made of terracotta - but you can use a large upturned pot, bucket or bin around 45cm high or taller. Block any holes in your chosen cover to ensure the plant is in complete darkness. Your plant will panic and send pale, tender stems up searching for the light.  Check every week and when these reach the top of the cover (about 5 weeks) they will be ready for harvesting. 

All this growth takes a lot out of the plant.  So, forced rhubarb plants will not usually produce much of a crop later in that season.  Therefore you may want to have some plants you force and some you don't.   

How to split Rhubarb Crowns

Splitting, or dividing rhubarb crowns is a good thing for the plant and gives it new life, It is easy to do – dig the existing crown up, then cut it into sections using a spade or garden knife.  Try and ensure that each section has 2 or 3 buds and a good number of roots.  Chop out any old, woody material from the centre. Replant the new crowns you have created according to the planting instructions for a new crown as outlined above.   

Harvesting

As we said above, do not harvest the stems from your plant in the first year. In the second year resist again if you can but if growth appears very vigorous then you could pick just a few stems.  In subsequent years you want to be harvesting between a third and half of the leaves to allow the plant to carry on thriving.  Reduce your harvesting after June as you could weaken the plant and leave it without enough resources for active growth.  

How to harvest Rhubarb

Its very tempting to snap stems off but instead, hold the stalk at the base, gently twist and pull upward to ease it out of the ground. Worth noting that only the rhubarb stalks are edible. Never eat rhubarb leaves as these are extremely poisonous – just add those to the compost heap.

Pest & Diseases

Crown rot

This is caused by fungi or bacteria infecting the crown. When your plant is suffering from this it will look wilted and sickly.  If left unchecked crown rot will cause the plant to die. To save the plant, cut back into healthy tissue and remove all affected areas.