It’s National Allotments Week, coinciding with a time when our harvests are hitting a peak. The thing is, I am on holiday away from my allotment, so my fruit and vegetables are going unharvested. All I can think about are my tomatoes, in pots, drying out and screaming for some rain. The potatoes in the ground will be fine. The climbing and runner beans were still in flower when I left, so should be ready when I get back. Most of my soft fruit – the summer raspberries, strawberries, all the currants and gooseberries – had finished by the time I’d packed my suitcase. There will be blackberries and the first autumn raspberries to pick when I return. It has rained a bit in London. Maybe there will be some tomatoes left for a homecoming salad. But every August, when I am on holiday, I wonder whether there is any way round having an allotment that fits in with the school year.

While I’ve been away I’ve been plotting next season: redrawing my allotment plan for 2017, and writing a wishlist of new plants. On this list will be apple trees to add to my growing urban orchard, inspired by a visit to the cider-making monks at Ampleforth in North Yorkshire – more on that in my next post. But after picking some juicy hybrid berries in the garden where we are staying, I am also going to add a few of these to my shopping list.

Three of the best-known hybrid berries are the boysenberry, tayberry and loganberry, all crosses of blackberries and raspberries to varying degrees. Of the three, the boysenberry looks most like a blackberry: it ripens to a dark maroon to black, but is slightly longer than its ubiquitous hedgerow cousin. It is a cross between a blackberry and a loganberry, which explains its deep wine colour. Squash it in your fingers slightly as you pick it from the bush, and it bleeds redder than any blackberry. Its taste is sweeter than the blackberry, but more full-bodied than the raspberry.

I cooked some in a crumble this week and they held their shape beautifully. Next, I am going to make some boysenberry jam. Thanks to Adam Behr on Twitter, who points out that Simon and Garfunkel referenced this fruit in their 1968 song “Punky’s Dilemma”: “I prefer boysenberry / More than any ordinary jam / I’m a ‘Citizens for Boysenberry Jam’ fan.” Just like Simon and Garfunkel, I can declare the boysenberry is my new favourite soft fruit. In the hybrid berry Olympics, it would win gold.

Next, the silver medal must go to the tayberry, named after what happens to be my favourite river in Scotland, the Tay. As I picked these berries from their straggly canes I imagined myself in Perthshire, with the chilly smack of that river’s water on my toes and the smell of wet earth and silver birch in the air. Tayberries are bright red and similarly large like the boysenberry. Their taste is sweet, just like the raspberry. But the tayberry has a succulent shine compared to the raspberry with its slightly matt finish.

This leaves the loganberry picking up the bronze medal. It is smaller than the tayberry, and has a tarter taste, and so must come last in this little hybrid berry race. A tayberry can be eaten straight from the bush, but you would only really want to cook a loganberry. I am told that loganberries do make excellent jam – they need all that sugar to take the edge off the tartness.

I will plant all three at Plot 35a this coming winter. Plant bare-root canes between November and February – they are cheaper to buy than pot-grown ones. Hybrid berries fruit on canes that grow the previous year, so prune them like summer-fruiting raspberries, cutting out canes that have just carried berries and tie in new growth, which will provide a crop the following year.