Why cut just below the bottom node?

[hoosierbanana]

I took these pics last season and just found them digging around. They show a cutting that had rooted and suddenly collapsed. What follows is a dissection of that cutting showing that a microorganism invaded the pith, causing all roots in the lowest section to die. It happened to several that were cut with a half inch or more below the bottom node.

[AscPete]

Thanks for starting this Topic...
Its been my observation that,

The bottom end of the cuttings should be cut just below a node, because the pith will die
and create a hollow which will be an opening for microbes. If you are using a liquid rooting
hormone it should be applied at the start of the rooting process and only on the cut bottom end
of the cutting.
In the early stages of rooting and growth organic additives and fertilizers will introduce microbes
and spores which may cause molding and rot on the cuttings. In this case remember the
motto "Less is More".

I've bare rooted several healthy looking young fig trees from prominent nurseries and have found similar rot growing from the bottom up.
All were cut with excess material below the node and a few were also cut on the diagonal...

[hoosierbanana]

I am being a stickler Pete. I agree that raw organic fertilizers are likely to cause problems, but things like seaweed extract, beneficial microorganism inoculants, and other carefully processed organic products are safe as directed.

[AscPete]

Yes, the processed, sterilized and packaged organic products are probably OK.
Composts, Potting "Soils" and Bulk Organic materials may do more harm than good, introducing Fungus Gnats and Harmful Microbes..

[hoosierbanana]

Agreed.

[Kelby]

Good advice, I learned from my losses.

[Rewton]

This is useful to know - thanks! I usually cut just below the bottom node but will be religious about it from now on.

[pppldj]

This old book has some interesting reading.

[hoosierbanana]

That is usually the case but sometimes the solid division will be diagonal through the cutting so that a straight cut through the leaf scar will expose the beginning of the upper pith. Rare, but something to check for and avoid if cutting directly through the node.

[Darkman]

If pith is exposed perhaps it could be sealed with a Elmers glue stick. It is used to seal the top of scion wood in tree grafts.

[cyberfarmer]

Why didn't I know this before? Thank you.

[cis4elk]

Even when following all the rules, sometimes sudden cutting death(from bottom rot) occurs anyway. I just had one today that I had to intervene with. I knew it was going to happen, over the last week or so that cupped treeling was exhibiting the classic behavior. (We're talking about a cutting which is hardened off to dry air) During the day it would wilt slightly and once the light levels went down it would regain good turgor pressure, previously it had been fine. Anyway, I'll start a thread all about if it works, nothing unprecedented..just a way to save a cutting, hopefully.

[AscPete]

Its been my observation that sometimes the bottom of the cutting doesn't fully callus and although it looks like its growing properly, the bark starts rotting away.
It was usually due to too much moisture at the bottom end which slowed or delay the callus formation. Good Luck with your cutting.