Article by David Marks
Our main sweetcorn article can be found here. But sometimes our readers ask specific questions which are not covered in the main article. This page lists their comments, questions and answers. At the end of this page there is also a form for you to submit any new question or comment you have.


Date: 03 May 2020 From: John
QUESTION: : I foolishly started my sweetcorn early this year in pots then transplanted them to the allotment 2 weeks ago. Then the hail came and overnight temp dropped to 5C. They now look a bit poorly… will they survive ?

ANSWER: I really have no idea. Sweetcorn are sun loving plants and, as you have found out, do not appreciate cold / bad weather.

It looks like garden centres won’t open for some time, so the possibility of replacing your plants with new ones is not good unless you can source some plug plants online.

Much depends what the climate is in your area. However, if you have some seeds left over I would definitely sow them immediately. Germinate them indoors and you may well have plants which will catch up a missed week or so. This summer may turn out to be warm and if that’s the case, seed sown now will almost certainly catch up.

My top advice for sweetcorn is to mulch them as much as possible. Woodchip, repeated addition of lawn clippings etc. is hugely beneficial. The mulch traps in moisture and heat as well as deterring weeds.

Date: 23 July 2019 From: Bernard
QUESTION: I have grown Lark and it seems ok ,but some have developed side shoots, is this normal/desirable?

ANSWER: Many sweetcorn varieties produce side shoots. With Lark I would let the plant produce two sweetcorn (select the largest two) and remove any other side shoots. This will encourage the plant to put all its energy into producing the two remaining cobs.

Date: 3 April 2019 From: Nathan
QUESTION: I’m confused about whether it is acceptable to grow superweet and tendersweet/extra-tender corn in proximity to each other, or if they should be isolated to avoid cross-pollination?
I plan to grow Mirai 003 (I think also known now as Mirai Picnic) and Lark F1 this year and would like to know how far apart to keep them?

ANSWER: Mirai 003 is a super sweet variety and the cobs may well suffer if grown near any other variety. Lark F1 is an extra tendersweet variety and it will not be affected when grown near other varieties.

I will say straight off, I have never experimented with growing a super sweet variety next to a different variety, the opinion above is generally accepted and I have stuck to it.

Sweetcorn is wind pollinated so in the worst situation cross pollination could occur in all but the largest of gardens. How high the real risk is if the two varieties were gown 5m apart I don’t know but I would judge it to be minimal.

I regularly grow different tendersweet varieties together with no problems. That’s the most help I can be.

Date: 01 September 2018 From: Peter
QUESTION: I grew Lark and Sundance sweet corn this year and nearly all of the cobs
were tough and inedible. Was this the hot weather, cross pollination from plants on other allotments or something else? Help!

ANSWER: First, the hot weather will only have helped sweetcorn. They originate from Central America so they appreciate warmth and sun.

As far as cross-pollination is concerned, Lark will not be affected, the same probably goes for Sundance but I would need to check that out in more detail to be 100% certain.

The prime reason for tough sweetcorn is over cooking. A lot depends on how you cook them, but if you overcook them, they will definitely become tough. I always (well nearly always nowadays) boil mine. Lightly boil for five minutes maximum.

For best results cook immediately after picking. If that’s not possible, store in the frige for a day or two. If not stored in the fridge they will rapidly become inedible.

The final reason for sweetcorn being tough, and a very common problem, is that the sweetcorn was harvested too late.

I hope one of those ideas helps you.

Date: 04 February 2018 From: Paul
QUESTION: You mention several times that sweet corn plants should be restricted
to a certain number of cobs. How you you achieve this? Is it simply a matter of pulling/cutting off additional cobs as they form?

ANSWER: Yes, that’s exactly correct. As soon as the required number of cobs have started to form, any additional ones are picked off as soon as they are noticed.

Date: 21 May 2018 From: Roger
QUESTION: My seeds have not set. Dug a couple up and found small worm like creatures attached to the seed. Also very small white things also present around seeds.

ANSWER: I don’t know what bugs those are specifically, there are so many. I know how you feel, it’s a pain in the neck. I would suggest that next year you sow the sweetcorn seeds in pots and transplant them when 8 to 10cm high.

Date: 21 August 2015 From: Rod
QUESTION: My Sweetcorn stands shoulder high, looks full of life, but shows no sign of cob growth or pollenating tassels at top of plant, Plant bought from nursery

ANSWER: I have added a new section in our pest page which answers this question.

Date: 29 May 2016 From: Jenny B
An excellent website, not only the sweetcorn pages but every page I have visited I have found informative. Thanks for the hard work.

Date: 26 July 2015 From: Carolyn
QUESTION: I’ve grown sweet corn for many years. This year I’m trying ‘Ambrosia’ in a raised bed. Every plant is producing 5 cobs. Do I let them all mature or remove some? Advice please!

ANSWER: A lot depends on the variety and where you are in the UK. Ambrosia looks to produce slightly smaller than average sized cobs. I live in the Midlands and always err on the side of caution – no more than than 2 cobs per plant. If I leave more they never seem to mature properly. Maybe you can leave three on if you are in a warmer part of the UK.

Date: 7 June 2015 From: Steven Doble
QUESTION: I have planted out 20 sweetcorn plants as a trial, I am new to growing vegetables and have noticed that the leaves on the sweetcorn plants are turning yellow, is this normal or is it a soil problem i.e. too acidic/alkaline, any suggestions.

ANSWER: I have added a new section in our pest page about this problem.


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