Growing Sweet Corn from Sowing to Harvest

, written by Benedict Vanheems gb flag

Ripe sweet corn cob

There’s something pretty special about a handsome stand of homegrown sweet corn. But the real prize lies in harvesting it. Picking the cobs, then excitedly peeling back the sheath to reveal those full, creamy kernels is just magical! And there’s no better treat than cooking them straight away for the sweetest possible taste. If you fancy growing your own sweet corn this year, you’re in good company. Here are some tips to set you up for sweet success...

Growing Super Sweet Corn

Grow sweet corn in a spot that receives plenty of sunshine, in soil that’s been enriched with a lot of well-rotted organic matter such as compost. Corn’s lofty habit and feathery tassels makes it an attractive plant in its own right.

Hybrid varieties are usually the most reliable choices for cooler climates. If you want especially sweet cobs, then choose varieties described as such – many will even have the word ‘sweet’ or ‘sugar’ in the name.

How to Sow Sweet Corn

Corn loves the warmth and won’t tolerate frost. While the seeds may be sown directly outside once the soil has warmed up, the safest way to sow is into pots in the protection of a greenhouse, hoop house or cold frame. That way you can begin sowing three to four weeks before your last frost date and enjoy a head start on outdoor-sown corn – a huge advantage in shorter growing seasons.

Sow eight to ten seeds half an inch (1cm) deep into four inch- (10cm) wide pots. You can use any general purpose or seed-starting potting mix. Alternatively, sow into smaller pots or plug trays, sowing two seeds to each pot or module then removing the weakest of the two seedlings.

Sweet corn hates the cold and is best started off in a greenhouse, hoop house or cold frame

Keep pots moist as they grow on. Ideally they should be about six inches (15cm) tall by the time you’re ready to plant them outside. Harden off the plants as your recommended planting time approaches by leaving them outside for increasingly longer spells over the course of about a week.

How to Plant Sweet Corn

Sweet corn is wind-pollinated, so instead of planting them in a long row, set your plants out in a block for the highest chance of success. If the corn isn’t well pollinated, it will still grow but will be missing many of the kernels from the cob.

Remove your young plants from their pots, then very carefully tease their roots apart. Try to retain as much of the soil around the roots as possible. Now plant your sweet corn 18 inches (45cm) apart in both directions. Dig a hole for each plant, feed the roots to the bottom of the hole then firm the soil back in.

Sweet corn is best grown in blocks rather than rows for the best harvests

Sprawling squashes make a great companion for sweet corn. The squash will carpet the ground and help suppress weeds as the sweet corn grows skywards.

Caring for Sweet Corn

Remove any weeds that pop up within your sweetcorn by hand and continue weeding while you are still able to get between the plants. Sweetcorn is sturdy and shouldn’t need supporting. It will appreciate watering in very dry weather, particularly from late summer as the silks appear and the cobs begin to form.

Sweetcorn is ready to pick when the silks turn dark brown

When to Pick Sweet Corn

The cobs are ready to pick when the tassels at the end turn dark brown, usually around six weeks after first appearing. If you’re unsure whether a cob’s good to go, try the fingernail test. Peel back the top of the protective sheath then sink a fingernail firmly into a kernel. If it exudes a creamy liquid, it’s ready. If it’s not quite there the liquid will still be watery, and if there’s no liquid the cob is already past its best.

To harvest, twist the cob and pull it away. Aim to enjoy your harvested corncobs as soon as you can. Try it boiled or barbecued then served up with lashings of butter and pepper!

Corn is sweetest cooked as soon as possible after harvesting

Do you know there are even some gardeners who swear by getting a pan of water on the boil before harvesting their corn so it can go from plot to pan in mere seconds? If you have tips for growing or enjoying super sweet corn, then please share them in the comments section below.

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Show Comments


"Does sweet corn have suckers? Each stalk has 2 stalks coming out. Don't know whether to remove or.leave them.Never seen this before."
Breysach Rebecca on Tuesday 10 July 2018
"Hi Breysach. Yes, sweet corn can produce suckers, which are called 'tillers' on corn. They're actually a sign that the plants are growing in good conditions, though can sometimes come about if plants are injured or damaged in some way, perhaps by hail or insect damage. Whether you leave them or not depends on your growing season. The tillers have the potential to grow on into full-sized stems, which may even produce bonus ears of corn, though this is very much down to chance and how long your summer is. You do not need to remove tillers - just leave them be. They aren't harming the plants and removing them risks harming the main stem. Let them grow on - they may come away naturally, or they may grow on to boost your harvest. Either way is fine."
Ben Vanheems on Tuesday 10 July 2018
"Can I use kernels from a store bought cob as seeds for next year's crop?"
Gerry Ring on Thursday 1 November 2018
"You could dry the kernels out to then store as seed, but the trouble with that is that the resulting seedlings may not come true to type - i.e. they may produce cobs nothing like the ones you bought. This is because a lot of commercially grown corn in hybridised, which means the seedlings are not like the parent plants because new seed must be specifically produced by crossing two types of parent plants, each and every season. There is also the risk that cobs may have been treated some way to extend shelf life, thereby compromising viability of the seeds. It's always best to start from seed sold specifically for sowing."
Ben Vanheems on Thursday 1 November 2018
"can you plant early variety sweetcorn with a later one next to each other."
Gillian Edwards on Thursday 25 April 2019
"Hi Gillian. If you mean side by side, rather than interplanted in the same patch of ground, then yes, absolutely. They may flower at different times. And even if they do flower at the same time and cross-pollinate, this won't affect the quality or distinctiveness of the final cobs. Only if you were to save seeds to sow next year would you potentially come across problems. So yes, if it's simply to eat both this year, go for it. Absolutely, yes, no problem. The blocks of sweetcorn would need to be physically separated "
Ben Vanheems on Thursday 25 April 2019
"Can you plant them straight into the ground outside ?"
Hattie Wade on Sunday 5 May 2019
"Yes, absolutely. You would need to do this once the risk of frost has passed though. The reason most people living in mild/temperate areas start corn off inside is to get a head start, so they are already young plants by the time they go outside. But you can certainly sow direct if you prefer. Sow two seeds per position, at their final spacings, then thin to leave the strongest at each."
Ben Vanheems on Tuesday 7 May 2019
"Growing corn is easy. I prefer Peaches and Cream variety of corn. It is delicious. Do make sure your dirt has good compost on it. Some farmers put manure in their gardens. It must be on the soil for three months before the garden is plowed to plant seeds in."
Rebecca Williams on Saturday 11 May 2019
"Hi Rebecca. Thanks for your tips and experiences. Corn will definitely appreciate a beautifully fertile soil."
Ben Vanheems on Monday 13 May 2019
"do i need to dry the individual kernels from a cob before planting them in the ground? i found some from last year in my freezer... cannot find any corn seed in this area , will planting fresh corn in the ground result in a crop or not?"
William on Friday 31 May 2019
"I think that if the corn hasn't dried out then yes, it's unlikely to germinate, sorry. The kernels need to mature fully on the plant to become viable seed, which means allowing them to dry out. Have you looked online for a source of corn seed - there must be plenty of online retailers who can post out to you?"
Ben Vanheems on Monday 3 June 2019
"is it possible to improve sweet corn by pruning i.e. cut top off or removing leaves? "
Roy Babbington on Wednesday 4 September 2019
"Hi Roy. I've never heard of this being done, so my inclination is that no, this wouldn't help improve sweet corn. Corn tend to reach a certain height and then stop growing so that energy is diverted into producing the cobs. Removing leaves would remove some of the plant's means of producing the energy to do this."
Ben Vanheems on Wednesday 4 September 2019
"Hi Ben Having a pot of boiling water is a no no, why boil away all of those lovely vitamins when all you have to do is put the corn (as it comes off the plant) straight into the microwave (10 mins) or an oven (15 mins). Take them out carefully, peel back the leaves and you have a ready made handle. Pull off the beard and you are good to go. Try it and you will never boil it again. The leaves hold in all of the moisture and flavour."
Sandra on Thursday 5 September 2019
"Many thanks for the suggestion Sandra. I'll give this a go next time. :-)"
Ben Vanheems on Thursday 5 September 2019
"It won't let me put in the link, but if you google Mr Fothergills News Blog Growing Sweet Corn From Sowing To Harvest it has exactly the same text as your webpage, along with a few of the same pictures. Kinda odd. "
Amanda on Friday 31 January 2020
"Hi Amanda. Thanks for letting us know. That's absolutely fine, they have are permission for this. We're always keen to get our handy articles and videos out there, far and wide!"
Ben Vanheems on Monday 3 February 2020
"Hi Ben, I have 3 comments 1) I definitely second Sandra’s idea of microwaving Sweetcorn cobs in their own natural wrapping, but like you said pick the cobs immediately before cooking - they are so sweet. 2) This year I year noticed on the packet instructions that some types of Sweetcorn Should NOT Be planted near to each other (it did not say how far is near??) to avoid cross pollination which would spoil the sweetness. The super sweet ones are most at risk if grown near standard or sugar enhanced types). 3). The three sister method works best for corn and bean/ peas that can be left till fall/ autumn before picking ( to be dried and possibly ground for flour). It’s difficult to walk amongst Sweetcorn plants to pick fresh cobs when they are surrounded by squashes and legumes. "
Donald on Thursday 16 April 2020
"Hi Donald. Thanks for those comments. And yes - your third point in particular makes very good sense given the issues with access. So beans and peas for drying for the winter. Thanks for sharing these tips."
Ben Vanheems on Thursday 16 April 2020
"Hi, how deep do I put the seeds Into the ground please. "
Keith chaloner on Friday 17 April 2020
"The seeds should be put about half an inch or 1cm deep."
Ben Vanheems on Monday 20 April 2020
"Hi, last year mice ate so many of our corn cobs, spoiling every one just before they were really ready for us to eat. Is there anyway we can prevent this? The year before a badger broke down the rabbit wire fencing and knocked over and ate every cob all in one night. I know how to sort out the badger by strengthening the wire fencing but the mice, no idea. I’d love to actually eat some of our home grown cobs this year. "
Angela on Saturday 25 April 2020
"Hi Angela. I've had no end of problems with mice digging up and eating the sown seeds, such that I'm now left with just six young plants to plant! I feel your pain. I'm not really sure what to suggest, as mice can get into such small areas, it's likely impossible to preclude them from getting in. You could try growing stands of corn within a fruit cage, with finer mesh netting, but I suspect the mice will find a way in here too. The only alternative would be to get a cat, but then the cat would need feeding and would likely kill lots of other wildlife too! Sorry, I know I'm not being much help with this."
Ben Vanheems on Monday 27 April 2020
"Hi Ben, In relation to the last question about mice, I have similar problems and have used mouse traps. These do need to be covered with netting to prevent catching birds but the mice are tempted by the bait and will find their way under the netting. Hope this helps. Ross"
Ross McCarroll on Wednesday 29 April 2020
"Thanks for that Ross, that's appreciated. Luckily all my seedlings - or the tasty ones to mice at least - have now grown out of the vulnerable stage and are doing well. But I'll bear your tip in mind for next year."
Ben Vanheems on Thursday 30 April 2020
"I love the idea of growing Squash next to the corn, I grew my first crop of corn last year as I was experimenting I didn't grow many, however I've sown lots of corn this year, which is coming on nicely in the poly tunnel. I've sown lots of different varieties, if I plant out these varieties at different times will I still be able to plant next to each other? Thanks"
Erika Taylor on Saturday 2 May 2020
"Hi Erika. Generally it's best to plant at the same time so that plants are getting the same growing conditions at once, which will encourage a more even growth rate so they are in flower at the same time, which will improve pollination and cob set. I would caution that different varieties may have different growth rates, so I would at least aim to plant each individual variety out at the same time, so each variety is clustered together, just in case they do flower at different times."
Ben Vanheems on Monday 4 May 2020
"Last year, due to a huge amount of vegetation being cut back near by, we were plagued with rodents on our allotments the had a good nibble on our corn. Does anyone have any good suggestions for protecting corn cobs from unwanted visitors?"
Carolyn on Sunday 24 May 2020
"Hi Carolyn. That is a big nuisance. I've never had this problem myself so will be interested to see if anyone has any advice. I would imagine harvesting the corn in good time, while the green sheaths are still tight over the cob would help, as it would be harder for the mice to nibble through. "
Ben Vanheems on Monday 25 May 2020
"Should the extra small shoots from the bottom of the plant be removed?"
Shuyuan on Thursday 11 June 2020
"The extra shoots are called 'tillers' and have no detrimental effect on the main stem. They often form in favourable conditions - so you're clearly doing the right thing! There's no need to remove them - no beneficial reason to do so. The main stems will naturally out compete the tillers and you will get a good crop with or without them."
Ben Vanheems on Monday 15 June 2020
"ive never growen anything in my life but with lockdown one of the thing ive tried iseweet corn do I cut off the maze at the top or leave it "
bridget Borland on Sunday 30 August 2020
"Hi Bridget. Leave the sweet corn untouched - all parts of the plant. The cobs are harvested once they are nice and full, as described above. "
Ben Vanheems on Tuesday 1 September 2020
"Should the corn be given regular feeding? I usually only get one cob per stem but know other people get more . I have been planting earlier than I used to in Western Australia - August seems to work better than later as less likely to dry out when the heat hits. I also steam my corn for just a couple of minutes"
Gwyn on Saturday 5 September 2020
"Hi Gwyn. Personally I don't feed corn after planting. Soil preparation is key, including laying on/digging in plenty of well-rotted organic matter such as compost. Ensuring a good, rich soil is key, and helps somewhat with water retention in hotter climates such as yours. That said, I would imagine applying a liquid feed or slow-release organic fertiliser at planting time would certainly give plants a good boost, and possibly encourage them to set more than one cob per plant - so worth a try."
Ben Vanheems on Monday 7 September 2020
"It's our first year of growing this. We have a cob that looks quite big, but there are no silks growing on it. Do you think this will ripen and be ready to eat?"
Lorraine on Tuesday 29 September 2020
"Hi Lorraine. It may be just that the silks have fallen off or been chewed off or similar. If the cob is looking quite big then that is a very promising sign. I would peel back the top of the sheaf to take a look at the kernels - see how they are coming along. I'm not sure where you are, but in most regions it's now pretty late in the season, so I would imagine they almost certainly are now ready. I harvested my cobs yesterday - a bit late to be honest, but they were still exceptionally sweet and delicious."
Ben Vanheems on Thursday 1 October 2020
"Hi do you know of any research that says which way rows of corn should orientatate. I know that they are supposed to be in blocks which is not possible (going to do rows of three or 4 but longer than a block."
Sonia on Thursday 10 December 2020
"Hi just wondering if in a situation of not being able to plant in a block if 3 or 4 rows wide will be okay and which way shoild the rows orientate."
Sonia on Thursday 10 December 2020
"Hi Sonia. I would probably orientate the rows north-south, so that the plants all get some morning and afternoon sun evenly. But to be honest, if they are in a sunny position anyhow, I don't think it would make a big difference."
Ben Vanheems on Thursday 10 December 2020
"Here in sub-tropical Brisbane, Australia we can grow corn all year round. We don't have the same animals here but possums are the bane of my existence. My last crop of about 50 plants produced, on average, 2 cobs/ plant. As I knew they were ready I headed out to pick some for my dinner. When I arrived I found that possums had eaten every cob off the plants. They had meticulously peeled back the husks and eaten every kernel. I now net my corn which has the added benefit of increasing pollination."
Peter Turner on Sunday 2 May 2021
"Oh Peter - that must have been heartbreaking! Well done for not despairing and coming up with a solution though!"
Ben Vanheems on Tuesday 4 May 2021
"I've heard planting corn plants, started in the greenhouse, benefit from being planted out quite deeply. The idea is that, like tomatoes, corn produces roots from buried stems which helps to anchor the plant. Is this correct?"
Guy Riley on Friday 14 May 2021
"I haven't heard of that Guy, but thinking about the way roots often pop up at the surface close to the base of the main stem, that does make sense. It may be worth trying a few plants this year to see and compare for next season?"
Ben Vanheems on Monday 17 May 2021
"After harvesting the corn n I pilled up the corn trees to break down but then after a while I realized that new corn plants were growing. Do they grow and bear as normal corn???"
Kofi on Monday 26 July 2021
"Hi Kofi. They could potential do so, yes, but I wouldn't imagine this is a very reliable way to grow more corn. Could be fun to try though!"
Ben Vanheems on Monday 26 July 2021
"I’ve grown sweet corn this year in a fruit cage - about 30 plants in a square with the plants about a foot apart. They’ve all produced cobs but mostly these are very good in the bottom 4 inches or so but then have very limited success above that. Any idea how I can get full length cobs."
Michael Worthington on Monday 4 October 2021
"Absolutely Michael. That sounds like a pollination issue. Check out our video 'Grow Perfect Corn Every Time', which includes a section on ensuring full pollination of the entire cob. Search for it in the search box above. Basically, tapping the plants will help to dislodge the pollen at flowering time, so that they land on the silks of the females down below. Or you could detach a ripe male tassel from the top of the plant, then rub this back and forth across the silks to significantly increase pollination success."
Ben Vanheems on Monday 4 October 2021
" Hi. We have got about 8 nice healthy looking corn plants standing about 50 cms high and planted close to 5 weeks ago.. We noticed a growth of maize coming out of the top of the plant. Just wondering if this is natural Thanks."
Brian Edwards on Sunday 17 October 2021
"Hi Brian. It's hard to tell without looking at it, but corn can put on quite sudden grown spurts, so it's probably nothing to worry about. Corn, once established, can also product 'tillers', which are branches that develop lower down in the plant - this is perfectly natural too and a sign of good growing conditions. "
Ben Vanheems on Wednesday 20 October 2021
"I last grew sweetcorn 2yrs ago when we had chickens, and the rats are the lot one night. We don't have chickens anymore, but I have seen an occasional rat. We also have a 25yr old tortoise who has free range of the garden. To keep them both out of the sweetcorn I plan to use the chicken cages to surround the sweet corn. Wish me luck"
John Essex on Saturday 2 July 2022
"The first line of your section "When to Pick Sweet Corn" seems to have an error/typo: The cobs are ready to pick when the tassels at the end turn dark brown, usually around six weeks after first appearing. I think you meant to say "silks" and I think 15-20 days after appearing is more like it. "
ed on Saturday 2 July 2022
"Hi John. That's sounds like a smart move to keep them out of your sweetcorn. Best of luck with this year's crop, and I hope you get to enjoy some cobs this time round!"
Ben Vanheems on Monday 4 July 2022
"Hi Ed. You are absolutely right - I got the tassels and silks the wrong way round - well spotted! Appreciate your eagle eyes on this one. Yes, you should of course wait until the silks are dark brown. :-)"
Ben Vanheems on Monday 4 July 2022
Paul Le on Thursday 21 July 2022
"Microwave a large cob 3 minutes full power straight from the plant Wach your finger’s as the covering is a bit hot A bit of butter FAB"
Bill on Saturday 23 July 2022
"After harvest I plan to dig in shredded stems/leaves and roots of my sweet corn (Gold crest F1) Will this improve the humus content of the soil ? will the rotting material have an allelopathic effect on next year's sowings (Peas or Potatoes)?"
michael howard on Wednesday 17 August 2022
"When it comes to recipes don’t discard making cream of sweetcorn soup it is very easy and our absolute favourite. Make a big batch and freeze in whichever portion sizes you prefer , then when reheating adding a little more milk or water helps to reconstitute "
Brian Eyers on Saturday 5 August 2023
"Sounds delicious Brian, great idea! :-)"
Ben Vanheems on Sunday 13 August 2023
"Hi Ben, Great article and comments to letters. I have a crop of corn in but the silks seem to be going brown well before the cobs are thick. What have I done incorrectly? John in Brisbane Qland"
John Earthrowl on Sunday 19 November 2023
"Hi John. Corn can behave erratically if stressed - too cold early on in the season, or in response to drought or nutrient deficiencies. Keep plants well watered if you can (if it is very dry). It may just be that the cobs will thicken up in good time and that they just need a few more weeks. I would just check the kernels from time to time, as described in the article. I suspect they still have a good amount of swelling to do and the silks turning brown is a bit of an anomaly. "
Ben Vanheems on Tuesday 21 November 2023

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