Sweetcorn

Looking after it

Water: Normal watering is enough. Water young plants until they are settled, then in dry spells. It matters most when the tassels appear at the top and while the cobs swell. Feeding: Sweetcorn needs rich soil, so grow it in ground full of compost or manure. A nitrogen feed when the plants are about knee-high gives a bigger crop.

Harvest and keeping

Once the silky threads at the end of each cob turn brown, check the cobs. Peel back a little husk and press a kernel with your fingernail. Creamy juice means it's ready, watery juice means wait. Twist the cob off and eat it soon, because its sugar turns to starch. Keep the cobs in the fridge and eat them within 2 days. Supersweet types last about a week. Freeze any you can't eat in time.

What can go wrong

• Gappy cobs. The cobs have gaps where kernels never formed, because too little pollen reached them. Plant in a block. On a still day, tap the tassels at the top of the plants to shake the pollen down.
• Birds and mice. Birds, mice and squirrels eat the seed and the ripening cobs. Sow indoors or net the seed bed. Cover the cobs once they form.
• Smut. Large grey-white swellings grow on cobs and stems, then burst into black powder. Cut them off before they burst and throw them away. Grow sweetcorn somewhere else next year.