Stock - Miracle Yellow

In general a lot of stock can be selected for singles / doubles when they are young seedling, normal separate cotyledons (first leaves) are typically doubles, and merged/conjoined cotyledons are typically singles. Lighter green seedlings is also another indicator of double vs darker green are often singles.

The StoX & Milla series can't reliably be selected for doubles by colour alone, as they typically had lots of much lighter green plants which were mostly double but still some singles. This colouration seems to be normal in these series, rather than it being an indicator of any deficiencies.

Most stock (except for the Quartet series) only typically produce one flower stem per plant, so do not pinch!

Some sort of support is generally advised, the taller they get the better your support will need to be.

Stock are best grown in the cooler months, their flowers will be more prone to damage in warm wet spells.

Being apart of the brassica family, it's best to try and time sowing after your white butterfly numbers subside in autumn but with enough time to make it to flowering before their population explodes back in spring - or be prepared to net them and/or treat with weekly/fortnightly sprays of BT (Bacillus thuringiensis - organic bacteria) to keep the munching caterpillars under control.