I have taken some hardwood cuttings of Sambucus nigra and Cornus and 'plonked' them in a pot of compost and left then outside. It was a bit of a spur of the moment decision so I didn't really do any prep. Will they root okay or I should I take new cuttings and dip in root hormone?
They will probably be fine as they're both hardy and prolific plants! For future - if you can get hold of some young willow (whilst it's still green and stripped of leaves) - then cut the branches and pop in a jar, cover with boiling water and leave for 24 hours. You can then use that to soak cuttings prior to 'plonking' or you can dilute it 3:1 with water and water cuttings with it. Willow creates natural rooting hormones - it's always good to make a demijohn early in the year and keep a stock of it. :)
Rooting hormones are Auxins (a group of plant hormones that control many different things in plants including plant growth habit, leaf shape and the formation of lateral branches), I personally never use them but one of the things they do do is encourage the formation of roots. They are produced in the growing tips of plants and travel down the stem towards the roots (or where the roots will form on your cutting) so I always leave the growing tip in my cutting until I am sure it has roots. The willow thing is probably just the build up of the auxins produced by the willow being excreted into the water by the cuttings, can't think of a scientific explanation for the honey but it's interesting to hear about, I might have to give it a go.
I love this question! As I learn more about propagation, I often wonder about the benefits of rooting powder generally. Anecdotally, everyone seems to be divided, even polarised, about its merits. If anyone knows of any specific good quality scientific papers on this, do share, thank you.
oh and ps. my own, very slapdash, Cornus alba cuttings all rooted easily sans powder, fyi
I've heard of honey for cuttings too! In India, traditional gardeners use it for rooting rose cuttings - but I'm guessing that would extend to all woody cuttings.... I think it has something to do with honey's anti-fungal properties, but I'm not sure ....