Best Sweetcorn Varieties for Scotland

Sweetcorn does best in a long, hot summer, which Scotland rarely gives it. Two things go wrong here: cold soil in spring holds back germinationA seed sprouting: breaking dormancy and putting out its first root and shoot, given the right warmth and moisture. Full definition →, and a cool summer leaves cobs that never fill. Varieties are bred to handle one or the other, so pick the one that matches your problem.

What Scotland means for the choice

Sweetcorn is tender, needs full sun to ripen its cobs, and goes out only after the last frost (see frost dates by region). An early variety gives the cobs the most time to fill before autumn. Cold-soil tolerance helps at the start of the season; a variety bred for poor summers helps with the whole of it. The sweetcorn growing guide covers sowing indoors, planting in blocks for pollination, and harvesting.

Earlibird, Lark, Swift, Mirai Picnic and Ovation hold the RHS Award of Garden Merit (AGMThe RHS's Award of Garden Merit: a UK-wide trials award for reliable performance, not a Scotland-specific recommendation. Full definition →), a UK-wide award rather than a Scottish one.

For a cold spring: Earlibird, Lark and Swift

Earlibird is an early supersweet with good tolerance of cold soil, which helps it germinate, and one or two cobs of about 20cm per plant. It's the safest default. Lark is an early extra tendersweet with very tender, sweet cobs, and it's more reliable in cold soil than most supersweet varieties, so it's the one to try if germination keeps failing. Swift is fast-growing and copes with cold soil too, giving one or two cobs per plant.

Rising Sun and Northern Xtra Sweet

Rising Sun is reliable even in poor summers, so it's the one for a season that stays cool throughout, not just a slow start. Northern Xtra Sweet is recommended, along with Earlibird, for colder growing areas. Neither holds the AGM.

Mirai Picnic and Ovation

Mirai Picnic is an early supersweet with at least two cobs per plant, and its robust growth suits poorer soil, useful on a tired allotment. Ovation gives the biggest cobs of those with a size given, 20–23cm, from a vigorous plant, but it's early to mid-season with no cold tolerance stated, so keep it for your warmest, most sheltered spot.

Which one for your situation

• Most Scottish gardens: Earlibird.
• Germination keeps failing in cold soil: Lark.
• Summers that stay short and cool: Rising Sun.
• A cold area generally: Earlibird or Northern Xtra Sweet.
• Poor soil: Mirai Picnic.
• The biggest cobs, on a warm, sheltered plot: Ovation.

For an early sowing outdoors, clear or black plastic mulchA layer of material spread over the soil around plants to suppress weeds, retain moisture, and improve soil structure as it breaks down. Full definition → warms the soil by 2–4°C, which helps any of these, and most of all the cold-soil varieties.

No variety resists sweetcorn smut or birds on ripening cobs. Protect seedlings from slugs and mice.

Common questions

Sources