Aim to sow
0.25 inches (0.64 cm) deep and try to ensure a gap of at least
3.96 feet (1.22 metres).
By our calculations, you should look at sowing Madame Lauriol de Barny about 35 days before your last frost date.
As Madame Lauriol de Barny is hardy, ensure temperatures are mild enough to plant out - wait until after your last frost date to be on the safe side.