I have a couple of Heliotropium plants, and I would like to grow more plants.
Can they be propagated from cuttings and, if so, when is the best time to take them?

Plants are easily propagated from cuttings.

Select sturdy shoots, cut them to about 50mm (2”) long, and trim off the lower leaves.

Insert the cuttings into pots of gritty compost and stand in a heated propagator until rooted.