Rhubarb season is in full swing. The rhubarb in our garden was late to arrive this year, but now the compotes are simmering and the pies and cakes (like this one) are in the oven.

Here are some interesting things about rhubarb that I learned (or reminded myself of) this year, mostly gleaned from this excellent article.

Fun rhubarb facts

Don’t eat the leaves! They are poisonous. Only eat the stalks, but cook them first.

Rhubarb has been cultivated in China for thousands of years and was brought to Europe along the silk road. Initially it was used medicinally, particularly to treat constipation, and as an antiseptic, mild painkiller, and treatment for shingles and toothache.

In the UK, some rhubarb is harvested by candlelight in darkened sheds, which is thought to produce the tenderest stems. Apparently you can hear the rhubarb growing.

According to farmers (and my father-in-law), you shouldn’t harvest rhubarb past St John’s Eve, June 23. By this time the stalks of the plants have built up unpleasant levels of acid. (Here’s another food tradition linked to St John’s feast day.)

Great rhubarb pairings include strawberry, vanilla, ginger, and elderflower. Fooby even pairs it with another ubiquitous spring favourite, asparagus.

The acid in rhubarb is potent—you should wait before brushing your teeth, as the acid weakens the enamel, and don’t store rhubarb in aluminium.

This is my mother-in-law Josy’s recipe and it’s super easy—make the batter and then top with seasonal fruit. Here I add some strawberries to the mix, but just rhubarb works too. Josy often makes an apricot version, and I do a plum apricot mix. For added crunch, sprinkle some slivered almonds on top.

400-500 g rhubarb, trimmed and peeled

200 g strawberries

100 g butter, room temperature

100 g sugar

2 eggs, room temperature

1 tbsp vanilla extract or paste

pinch salt

200 g flour

2 tsp baking powder

Preheat oven to 200 C / 400 F / gas mark 6

Beat the butter and sugar until fluffy, then add the eggs, vanilla, and salt. Beat until you have a fluffy, creamy mass.

Mix together the flour and baking powder and fold this into the butter mixture.

Scrape into a 24 cm (or 9 inch) springform pan or rectangular tart pan with removable bottom and arrange the rhubarb and strawberry pieces in a pleasing pattern on top.

Bake for about half an hour, or until you can really smell the cake and it is pulling away from the sides of the pan.

• The fruit ratio is up to you, add more or less rhubarb or strawberries as desired.

• Arrange in whatever pattern you like, making sure the fruit goes right to the edges.

• If the rhubarb is super sour, sprinkle with a bit of sugar when it comes out of the oven.