August is a productive month, but the tunnel needs reliable watering while you are away. Test any automatic system well before a holiday and make space for autumn and winter crops.
AUGUST IN THE POLYTUNNEL: AT A GLANCE
Beetroot, sprouting broccoli, cabbage, carrot, cauliflower, coriander, daikon, kohlrabi, lettuce, spring onion, pak choi, peas, radish, rocket, strawberries, sweet potato, potato, turnip.
Established crops from earlier sowings.
Aubergine, cabbage, carrot, cauliflower, celery, chard, coriander, courgette, cucumber, daikon, dwarf French beans, French beans, fennel, kohlrabi, lettuce, pepper, radish, rocket, spinach, spring onion, strawberries, sweet corn, tomato.
AUGUST IN THE POLYTUNNEL
1) Ask someone, very nicely, if they would mind spending between two and seven hours a week (depending on your soil type) watering the polytunnel – oh, and would they please do it in the morning, so the leaves have time to dry out?
2) Get an automatic watering kit, set it up and test it thoroughly before you leave so you can actually relax when you’re on the beach somewhere exotic.
Can you guess which is my preference? In fact, we’re very lucky in having good help close to hand – and as they’re farmers, they hardly ever go away themselves. But they’re not gardeners. Sheep, great. Chickens, no problem. Lettuces…huh?
And therein lies the problem. Nobody will take care of your garden the way you would yourself, even if they are gardeners themselves. A good friend of mine left his organic garden in what he thought were the safe hands of an experienced gardener and came home to find slug pellets scattered all over the place. Gardening is a process, and only by being there over time will you get a feel for how this plant is developing, how that one needs more water than those, and so on.
If you decide on an automatic watering system, you again have a variety of decisions to make. Some kits rely on a gravity feed from a central reservoir, while others are battery-operated timers that hook up directly to a tap. If you are a natural pessimist, you might want to avoid imagining the timer…malfunctioning…and test it thoroughly!
You’ll also need to choose between drippers, sprayers or soakers. Which one is best for a particular bed, or particular plant? If you use a dripper, all the water lands on one small spot of earth. If you use sprayers, they’ll soak everything within range – and unless you figure out the timing carefully you might end up with blight or mould. If you use soakers, you can’t really regulate the water from plant to plant as they leak along their entire length. This makes them good choices for beds rather than for individual plants.
As you can see, it’s not completely straightforward. But, automatic systems are great fun for people who like to fiddle with stuff, and, once they’re set up, they’re a huge time-saving on manual watering – because, of course, you don’t have to restrict their use to the days on which you’re actually away. Why not just leave it on all the time? You can move drippers and sprayers, or remove them from the system altogether. Soaker hose is a little more difficult as often it’s placed under a layer of mulch, or even buried just below the surface of the soil, and in trying to move them you risk damaging your plants. For more information on automatic watering systems, see the irrigation options section.
Local conditions matter: These are possible crops, not guaranteed harvests. Timing depends on the crop variety, earlier sowing dates, light, temperature and whether your tunnel is heated.
WHAT TO SOW IN AUGUST
Beetroot, sprouting broccoli, cabbage, carrot, cauliflower, coriander, daikon, kohlrabi, lettuce, spring onion, pak choi, peas, radish, rocket, strawberries, sweet potato, potato, turnip.
Note – we now have sweet potato. As a long-season crop it won’t be ready to harvest until Autumn the following year. Cuttings can be rooted in August to overwinter in pots before planting the following May. And, if you manage to save a few ‘first earlies’ from your spring potato planting, you could plant a few in the polytunnel this month in hopes of a harvest in December, imagine – home-grown new potatoes for Christmas dinner!
WHAT TO HARVEST IN AUGUST
Aubergine, cabbage, carrot, cauliflower, celery, chard, coriander, courgette, cucumber, daikon, dwarf French beans, French beans, fennel, kohlrabi, lettuce, pepper, radish, rocket, spinach, spring onion, strawberries, sweet corn, tomato.
Melons…and possibly even watermelons…even if you live in the north!
ESSENTIAL POLYTUNNEL JOBS FOR AUGUST
Tip 1
Continue sowing seeds for winter and the hungry gap. Don’t leave it until it’s too late! September sowings of many plants are unlikely to provide crops before the following spring, so if you don’t get around to it this month, you might have missed your chance.
YOUR AUGUST CHECKLIST
AUGUST POLYTUNNEL GROWING FAQS
Should I use automatic watering when away?
It can help, but test coverage, timing and reliability before leaving and arrange someone to check if possible.
What should I sow for winter?
The guide lists roots, brassicas, salads, peas and other crops. Choose varieties suited to your location and the time remaining before light levels fall.
Find individual crop advice in our Top of the Crops guide, or browse all monthly growing guides.
