Keep in mind when planting that Green Globe Improved is thought of as half hardy, so it will need cloching or fleece protection when the temperature dips. Green Globe Improved requires a loamy and sandy soil with a ph of 5.6 - 6.6 - it grows best in weakly acidic soil.
Try to ensure a gap of at least
1.95 feet (60.0 cm) when sowing to prevent overcrowding your seedlings. Soil temperature should be kept higher than
18°C / 64°F to ensure good germination.
By our calculations, you should look at sowing Green Globe Improved about 48 days before your last frost date.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Green Globe Improved is a half hardy plant.