By David Marks
This variety of Sweetcorn was first available in the UK in 2008 but is only recently catching on as a variety worth growing. It’s a supersweet type which has specific advantages and disadvantages.

Another distinguishing feature of Mirai 003 is the length of the cob. At only 15cm / 6in long it is 5cm / 2in shorter than normal but this has to be weighed against the fact that it regularly produces at least two or more cobs per plant, higher than the average. In addition the cobs are better filled on Mirai 003, right to the end.

Mirai sweetcorn has a history to it which is briefly worth explaining here. It was bred by Twin Gardens Farm in Harvard, Illinois, USA. Initially they thought the market for their sweetcorn was very limited because the crop is delicate and can only be harvested by hand – mechanical harvesters used for other varieties was not an option. However, they began to export the seed to Japan where less mechanised cultivation methods were popular.

The Japanese connection explains the name of the variety because “Mirai” in Japanese means “the future is almost here”. The variety became very popular in Japan and word spread back to the US about this early maturing and very sweet vegetable.

Slowly its popularity spread worldwide, reaching the UK in 2008. It is still not a popular choice of variety in the UK but over the past couple of years it’s beginning to appear in more and more seed catalogues.


This variety has many positive points in its favour but to be truthful you need to be aware of the negative points as well. These are summarised below:


  • The taste is everything a supersweet sweetcorn should be, sweet and juicy. It really is a treat to eat them raw, they are that sweet
  • The skin of individual corns is very thin which enhances the delicious taste even more
  • From sowing seed to maturity takes on average 74 days which makes this an early variety
  • Once established the plants grow strongly
  • Each plant produces more cobs than average although each individual cob is slightly shorter than average
  • The individual corns fill the whole of the cob, right down to the end which partly compensates for the shorter length of the cob


  • Because this is a supersweet variety it should not be grown near to other non-supersweet varieties to avoid cross-pollination which would affect the ripening and taste of the cobs
  • With this variety the seeds need to be sown at the correct time, at the correct depth and in the correct temperature. They are more temperamental than most because each seed has so little starch in it (it is mainly sugar) – starch provides energy for the seed to grow and with minimal starch the seeds need to get off to a good start


To get the growing conditions in the UK correct for the seeds we strongly suggest the you sow them in individual pots indoors. Timing of sowing the seeds and planting outside is also important.

The seed sowing and planting out dates shown below are correct for the UK average. If you want them to be even more accurate and adjusted for your area of the UK click here. It only takes a minute and the adjustment affects every date in this site and lasts for six months.

Sow seeds of Mirai 003 indoors during the third week of April (UK average).

Plant out the seedlings during the third week of May.

Full details for when, where and how to sow sweetcorn seeds can be found here and more information on their ongoing care throughout the growing season can be found here.



This variety of sweetcorn is not yet commonly found in garden centres but it is readily available from online seed merchants. Because of the delicacy of the seeds we strongly suggest buying the seeds only from specialist seed merchants which you trust. We would avoid buying them from online general retailers such as as Amazon or E-bay unless you know exactly who is supplying the seed.


USE: Eaten raw or lightly cooked

TYPE: Early maturing variety

SKIN COLOUR / TEXTURE: Rich yellow coloured cobs with sweet, very tender corns

STORAGE: Keeps in the fridge for five days or so, but tastes best if eaten fresh or within 24 hours. Freezes well

COB SIZE: Small sized, 15cm / 6in

REGULARITY OF CROPPING: Regularly produces a good yield once established

AWARDS: RHS Award of Garden Merit

SPECIAL FEATURES: A very sweet, early variety.