How to grow tasty veg in pots
Discover how to have containers bursting with produce, all year round, with Sally Nex’s guide to getting the best from pots
Herbs like parsley grow well in pots, either on their own or in the gaps around larger crops
There are plenty of great reasons to grow crops in pots, whether you are lucky enough to have a big plot to play with or growing on a balcony or in a courtyard. I keep pots of lush, babyleaf salads near the back door, where I can nip out barefoot to snip a superfresh bowlful for lunch. Herbs in pots, including seven different mints (which run rampant if grown in the ground), line the steps to my gate. There’s a big tub of strawberries on the deck, and my blueberries are in pots of ericaceous (acidic) compost, too – I couldn’t grow them otherwise, as they’d hate my chalky soil. Crops grown in containers demand more care than those in the open ground, though. So this month I’m sharing my tips for getting the best from your potted edible garden, so it’s bursting with produce throughout the year.
In some ways, veg in containers are easier to look after. You can move them into shade or shelter at will, and there’s no need for complicated crop rotations. Even slugs find crops harder to target in pots, especially when they’re raised on pot feet above a saucer of water – slugs don’t like swimming, and usually go elsewhere.
But containers are artificial environments, and it’s up to you to make them comfortable for your crops. Big containers, at least 45cm wide, win over fiddly little ones every time, as they don’t dry out as quickly and plants can spread their roots. Splash out on terracotta or plunder reclamation yards and online marketplaces for cheap second-hand plant pots, tin baths and butler sinks. And look around for items you can upcycle into containers for plants – as long as it’ll hold a good amount of compost and you can make drainage holes in the bottom, it’s worth a try. You can also build your own wooden planters out of reclaimed pallets.
Peat-free multi-purpose potting compost is fine for most annual veg. But fruit and long-lived herbs like thyme will be in the same pot for years, so need something more substantial. Loam-based composts, such as John Innes formulations, keep their structure for longer, so are better for plants that will be in the pot for several years. However, traditional John Innes compost formulations do contain peat (although much less than peat-based multi-purpose compost), so a good compromise is to use a peat-free multi-purpose with added John Innes, giving the best of both worlds. Mix in a handful of seaweed meal to each pot as a slow-release growth booster.
Making the right match
You can grow most veg successfully in pots (exceptions include asparagus) – the trick is to choose varieties that are specially bred for container life. Modern breeding breakthroughs mean that even veg-patch giants now come in container-sized versions. There are dwarf Brussels sprouts (‘Early Half Tall’), courgettes (‘Patio Star’) and runner beans (‘Hestia’). You can even grow potted pumpkins (‘Jack Be Little’).
Reserve tall containers for deep-rooted carrots and parsnips, and mix one part sand to every three parts compost to stop roots forking. If you don’t have any really deep pots, go for
I keep pots of lush, baby-leaf salads near the back door so I can nip out to snip a super-fresh bowlful for lunch
stubby little carrots like ‘Chantenay’ or, even better, round-rooted ‘Oxheart’ or ‘Parmex’. Parsnips, especially short-rooted ‘Arrow’, also grow well in old compost sacks.
Growing techniques
You can sow directly into your pot by scattering seeds onto the damp compost, or plant up your pot with plug plants – either buy them or grow your own in small pots on windowsills or in a greenhouse. Raise seedlings somewhere protected throughout the season and you can drop them into your big containers whenever gaps appear to keep crops coming.
Plant smaller veg 10-15cm apart, but give large plants like tomatoes and courgettes a container to themselves. Don’t be afraid to plant several types of veg in one large pot: if you’re growing climbing beans up a wigwam in a pot, use the space around the base for some lettuces, or sow beetroot, chard and herbs in blocks or stripes like a miniature veg patch, thinning seedlings to 10cm apart each way.
I also like to group containers into ‘three pot relay’ to guarantee steady supplies of fastgrowing crops that we eat a lot of, such as salad leaves, annual herbs, radishes, salad turnips and baby beetroot. I sow three pots with the same crop, but at staggered intervals, one every few weeks. By the time I’m sowing the last one, the first is ready to pick. Once I’ve harvested everything in the first, the second pot is ready to take over, at which point I clear the first, add some fresh compost (no need to empty out the whole pot) and resow straight away. Keep up this routine from March to September for a constant supply of fresh veg right through the year – no garden required.
See overleaf for tips on feeding and watering
Crops in pots really need you. They can’t search for moisture and nutrients like veg in the ground, so it’s up to you to give them the water and feed they need. That’s actually a good thing, as you have ultimate control: you needn’t worry about droughts or poor soil when growing in containers. But it does mean you can’t just leave them to it.
Container veg need watering every day – sometimes twice if it’s sunny. Make it part of your daily routine or set up an automatic watering system on a timer if you’re worried you might forget. Don’t be tempted to skip watering on rainy days, either: rain often just dampens the surface of containers without soaking in. To check, stick your finger into the compost, and if it feels dry underneath, water as usual.
Multi-purpose compost runs out of nutrients after about six weeks, so after that start adding a liquid seaweed feed to the watering can fortnightly as a general-purpose tonic to keep plants growing strongly. Stick with seaweed for leafy veg, but for anything that fruits, like beans, courgettes, strawberries and tomatoes, switch to potassium-rich comfrey or tomato feed once flowers appear to encourage fruiting and a bumper harvest.