This weekend is Open Garden Squares Weekend when you get a chance to visit over two hundred community gardens and private squares throughout London, some of which you can only get access to on this one weekend a year. There’ll be food and events and information wherever you go and maybe even some sunshine too. If you’ve got your plan for the day ready that’s fine, but if not, how about going to Bloomsbury, where there are thirteen gardens and garden squares taking part – including the Japanese Zen Garden at SOAS.

The Zen Garden is on the roof of the Brunei Gallery, just on the edge of Russell Square. (well, the first floor roof anyway – no wonder the guy on the desk gave me a funny look when I asked if there was a lift). It was opened in 2001 and is dedicated to Forgiveness, which is the meaning of the Kanji character engraved on the garden’s granite water basin.

A Zen garden isn’t much like a traditional English garden. Not many plants, for a start. Instead you’re offered a miniature stylised landscape where raked gravel represents flowing water and rocks become petrified islands.

In the SOAS garden there’s a central area of ‘water’ – raked silver grey granite chippings, with islands of Larvikite (a Norwegian stone) and slabs of basaltic rock representing a bridge.

Lemon thyme is used in a chequerboard pattern at the north end of the garden.

Wisteria climbs up a trellis to provide shade – and luckily it’s in flower at the moment.

The Zen Garden is quite small so let’s move on. Part of the fun of the weekend is visiting places you might have taken for granted and seeing them with new eyes – like Russell Square, too often just a rat run from the tube station to the British Museum, but with a wonderful fountain and an excellent cafe. The fuchsia by the cafe are in bloom now.

Or how about Brunswick Square, a small, peaceful garden next to Brunswick Place, originally laid out and railed in 1799? Your Open Garden Squares ticket also gets you free entry and 10% discount in the café to the Foundling Museum next to the Square, which tells the story of the Foundling Hospital, Britain’s first home for abandoned children and London’s first-ever public art gallery. There’ll be readings and music in Brunswick Square at intervals between 2pm and 4pm on Sunday afternoon.

From there you can walk a bit further to St George’s Gardens, which were the burial grounds for St George, Bloomsbury Way and St George the Martyr, Queen Square and the site of the first recorded case of ‘body-snatching’ (the theft of corpses for medical research and teaching) in 1777.

A bit further on, you reach Mecklenburgh Square, a grade II-listed two-acre garden laid out in 1810-12. It remains close to the original design, with fine mature planes and other ornamental trees, formal lawns and gravel paths. It’s normally closed to the public but you can get in to see it on Sunday afternoon 12:00–17:00. They plan to serve cream teas in a genuine Mongolian yurt.

Next to Mecklenburgh Square is Goodenough College with an enclosed lawned quadrangle surrounded by mixed beds. It’s also opening on Sunday afternoon 12:00–17:00.

I’ve only covered half of the squares and gardens in Bloomsbury that are taking part in the Open Garden Squares weekend. You can find out about the others, and all the rest of the gardens that will be open, on the Open Garden Squares website.

Tickets for the weekend (valid on both Saturday and Sunday and covering all the gardens) are £10, if bought before 8 June. Children under 12 are free. The ticket price includes a guidebook and all booking fees.

On both Saturday and Sunday, a guided walk around Bloomsbury for Open Garden Square ticket-holders starts from Bedford Square at 10.30am, 12.30pm and 2.30pm. No booking required. Or you can find your own way round pretty easily, as I did, using their mobile site.