Kitchen Gardener Rob Smith has some top tips and tricks with onions and leeks
Why not give my 'haircut' and watering tricks a go on your crops?
At this time of year it’s really important to check that any fruit trees or bushes that are grown in containers are kept well watered or they may abort their young fruit; and that’s the last thing you want!
Most of my fruit grown in containers has a layer of gravel on top of the soil so weeds can’t grow that easily, but this makes visually checking that the soil is moist impossible. Instead I scrape back the gravel and stick my finger in the soil to see if it’s moist; if not, it allows me to give them a good drink. I find that terracotta pots dry out more than glazed ones due to losing water through the sides, so keep a keen eye on them. Also, don’t forget to feed pot-grown fruit with a high potash feed as the fruit form, to encourage a higher yield.
I’m planting out some of my later-sown onions, including a beautiful pink-skinned one called ‘Isobel Rose’ that was bred in the UK, so it should perform well. Before I plant them out I’ve decided to give them a ‘haircut’; this basically means removing some of the foliage. The idea is it will make the plant create more leaves and bigger bulbs. I heard about this from a friend and know that this method of planting is used in Ethiopia on shallots, so I thought I’d have a go on half of my onions to see if it works in Sheffield! When the leaves are 30cm (1ft) long, you cut them in half (using the trimmings as spring onions), then wait for the leaves to get to 30cm (1ft) again and trim, and then once again (so three times in total). This is supposed to force the plant to create more leaves, which creates more energy for bigger bulb production. I’m also hoping that it’ll make the plants produce more upright leaves rather than ones that spread and touch their neighbours, as this should slow the spread of any allium rust.
My later-sown leeks have also been planted out. These always have a trim to the leaves and roots by about a third before being ‘puddled’ in. This is when you create a hole with the dibber, place the young leek in the hole with it sunk in lower than it was in its tray (usually a third to half) and then instead of backfilling with soil, you add water to the hole. This makes it collapse around the plant, which will help blanch it and create more white flesh on your leek. Talking
about leeks, my perennial ones have grown well in the cold greenhouse and are ready to plant out in their permanent homes. I’m growing them at the edges of a few raised beds as they can be left there and won’t get disturbed when I work the bed. Plant them at the level they were in the tray or pot, water and let them grow; just remember they’ll naturally die back in July or August before they start growing again, so you haven't done anything wrong.
You’re probably already harvesting your first lot of lettuce and salad leaves, so don’t forget to sow some more to keep you in summer salads; little and often is the best approach. I usually only sow around 12 seeds at a time, planting out
the best 10 lettuce every few weeks: that’s plenty for us.