The two most important things to remember when starting out with rhubarb is: grow plenty of it, and give it the sunniest spot available. Yes, traditionally, it has been allocated one of the shadiest areas of the garden, but this is a serious mistake. With the possible exception of chives and sorrel, deciduous rhubarb is one of the first edibles of the new season to become available in the garden, and for that reason, it will come away sooner if given the warmest position. Mine sits in a north-facing bed that is the first spot in the garden to catch the morning sun, and the last to lose it.
As for how much to grow, there are two of us in our household and the eight rhubarb crowns we grow provide us with only just enough for breakfasts, deserts, jams and chutneys (this is a versatile vegetable!). I also have two beds of rhubarb in my free-to-harvest roadside garden and passersby strip it bare each summer. So grow more than you think you will need and then some extra to give to neighbours and visitors to the garden.
Rhubarb can be grown from seed, and this is one way of obtaining some of the more unusual varieties (Kings Seeds offers at least two varieties but seed banks are a source of heritage rhubarbs you may never have heard of – check out these sources via the internet). Grown from seed, however, you will have a wait for two years for the plants to produce a harvest. The seed, which is quick to germinate, is encased a papery shell and it is best to soak it for a few hours before sowing to soften the case. Once the seedlings have been transplanted, they will do best if given a little protection from bright sunlight until they have hardened off. Shade cloth suspended above the plants can help with this.
More commonly, rhubarb is grown from crowns and, because the plants should be dug up and divided every 2-3 years (many people get away with leaving theirs in the ground for up to 5 years), you are almost certain to find a gardening acquaintance who is looking for a home for their spare roots. (I was inundated with replies when I advertised in my local newspaper for crowns to fill my roadside garden.)
As with the tradition of allocating rhubarb the shadiest part of the garden, many people believe that this plant requires little care and attention. Nothing could be further from the truth where this gross feeder is concerned. If you are satisfied with spindly stems (and only a few per plant) then by all means leave your rhubarb to its own devices, but if you want to harvest strong, thick stalks, enrich your rhubarb bed as much as you possibly can both at the time of establishing the garden and, again, when the crowns are lifted for division.
Dig the bed deeply (at least two spades deep, as a rough guide) and chop into the soil as much organic material as you can lay hands on in the form of aged animal manure, compost and seaweed (especially seaweed as it has moisture-retaining properties. Add a good sprinkling of blood and bone but skip the lime as this plant is a lover of acid soils. Be sure to remove any perennial weeds when establishing a rhubarb bed because this perennial is notoriously difficult weed around once its roots become established.
Rhubarb resents poor drainage so a raised bed is helpful if your garden is prone to becoming over-wet in winter. That said, rhubarb is also shallow-rooted and completely intolerant of dry soils. For this reason, once you’ve planted your crowns (so that they are just visible above the level of the soil), mulch around them well. And keep mulching as the summer progresses so that the crowns are kept adequately damp. In hot weather, water the plants daily. If their large leaves appear limp and papery, it is a sign that the plants are under stress and, if you check under the leaves, you will find the stalks withering. They will eventually drop off and, if conditions don’t improve for the plant, it will begin to send up seed heads – which is exactly what you don’t want. Once the plants begin to go to seed, their energy goes into the seed head at the expense of the stalks. Seed heads will also form at the end of the season so it pays to keep a watch and to snip them off before they put paid to the plant.
In cooler climates, rhubarb begins to die down in mid to late autumn, eventually losing its leaves completely (except in the case of one or two varieties). In warmer parts of the country, it will keep producing in a less vigorous manner and harvest will need to be restricted if the plants are not to be weakened come spring. In either case, late autumn or winter is the time to replenish the beds with the same organic matter you used when establishing them. It’s not always an easy task to work around plants that are still producing but by carefully lifting the leaves, it is possible to tuck compost and animal manure in underneath. I always completely cover my rhubarb beds in winter with kelp. While it is breaking down in the winter rains, it is also protecting the crowns from frost (in very harsh conditions, pea straw can be tossed over the crowns for protection).
Well cared for rather than being taken for granted, rhubarb is an enormously satisfying plant to grow and one that inevitably attracts the attention of garden visitors. It is also so ornamental (especially the red-stemmed varieties) that it does not look out of place in a perennial flower border. If you do decide to grow it, grow it well, and you will find yourself becoming as attached to it as I am.