How to know if cuttings have rooted?

josusa47

Is there any reliable way to know if cuttings have rooted or not?  Other than rooting them in water, of course, which doesn't work for all plants.

I've read that new leafy growth shows they've rooted, but in my experience, it ain't necessarily so.  Yesterday, for instance, I potted up some hawthorn cuttings which I'd taken in the autumn, and poked into a boxful of soil.  Most were obviously dead, but five had new green leaves.  When I dug these five out, only one had grown a substantial root.  Two had a couple of small roots, and two had none.  I found a sixth which had roots but no leaves.  I had a similar experience recently with rosemary cuttings which had new growth, some of them even flowers, but only two had rooted.

fidgetbones

I don't usually pot on until I see roots coming out of the bottom.

BobTheGardener

Hawthorn is difficult to root from cuttings and nurseries generally produce their stock from seed, so worth trying that.  In general, you need to leave hardwood cuttings undisturbed for a year as the roots break off so easily.

Kili

I usually after a 4 weeks or so tug the stem gently . If its not moving upward that means its usually anchored by the root. But I've never tried Hawthorn so it might be completely different for that .

josusa47

Thanks everyone.  @BobTheGardener, I've tried several times to grow hawthorn from seed, and never got it to germinate, though it self-seeds successfully enough.  I thought it might be one of those that needs to go through a bird's belly before it will germinate.  If commercial growers do it, clearly not.  I'll try again in the autumn.

BobTheGardener

Good blog about hawthorn from seed here, @josusa47 :

https://hartley-botanic.co.uk/magazine/hawthorn-propagation/

josusa47

Thank you, @BobTheGardener, that's useful and interesting.  So they don't germinate for 18 months; that's clearly where I've been going wrong.  I assumed that if they didn't germinate in the first spring, they weren't going to.  So I'll gather some haws this year and follow the instructions; I think I can improvise a cold frame.  And I'll take some more cuttings from the park.  About one in six rooted of those I took last year.

Fire

Like Jo, I find that the "new growth" method of checking cuttings is not at all reliable. I have done loads of Bumble salvia cutings this year and plenty of them get lots of new growth with no visible roots at all. I wait for roots to show from the bottom of the pot, too.