If you’ve been growing rhubarb for several years, then it is beneficial to divide the plants to keep them healthy. Equally, if you just want to grow more rhubarb plants, then dividing is a great way to do so.
We’d recommend dividing your rhubarb in year 4 or 5, but wait until the plant goes dormant – the leaves will start to die back leaving just the crown of the rhubarb plant exposed, with a few large buds visible. (Incidentally, if you simply wanted to move the rhubarb plant to a different part of the garden, you should also wait until it is dormant).
Take a good garden spade and carefully dig up the crown. Then, in a nice swift movement, use the spade to boldly divide the crown into separate crowns, leaving a bud on each. Now you can dig a few new holes (at least 60cm-70cm apart) to plant the new crowns, add some fresh compost then place the crowns so that their surface is an inch below the soil surface. That’s it! You should then see new shoots forming in late winter/early spring.