Beefsteak Tomato Seeds Heirloom Vegetable. Despite all the hybrid beefsteak varieties that are available, this remains our most popular main season tomato – mostly because of its consistent performance and heavy yields! Large solid fruits weighing up to 260 g (9 oz) are a rich red colour. Sow seeds indoors at least six weeks before last spring frost. Bears first ripe fruit about 60 days after transplanting. It’s important to irrigate frequently so the plants never wilt. Days to harvest are highly variable depending on growing conditions.  Indeterminate growth pattern (individual fruits ripen successively over many days).