Next year I plan to hybridise some alders, mostly crossing others with
A. glutinosa. In this last week I have been walking around eyeing up
my trees and planning things like how long-handled a cutter to I need
to get the catkins down from some of the trees.

One of the problems will be how to get fertile pollen to the cones
while both are fertile.

This year in Newcastle A. glutinosa opened its catkins at the the end
of February and the beginning of March. Depending on the weather it
may be earlier or later and I will watch carefully to see how they
open.

The problem is going to be to get the other pollens to the target
trees while both are still fertile. Some thoughts and invitation to
comment :-

* I found this year that to cut off a branch with unopened catkins on
it and bring it indoors (in the warm) brings on that catkin a lot.
That solves the problem when the target tree is the earlier?

But t'other way round?

* But if a pollen tree looks like producing its pollen before the
target tree, then will it work to do the opposite, cut the twig, and
put it in water in the fridge to hold it back?

* According to the books, pollen is produced before the cones are
fertile. Their fertility is shown by a red stamen showing. Is this a
reliable sign?

* Is it best to store pollen still on the catkin or best to shake it
off and store it loose? What is the storage life of pollen? Does
refrigeration work?

* A friend has given me some "pollen bags" (is that the right word?)
to put over the catkins to make sure that no other pollen gets in. But
he has no more, and he has lost the supplier's name and address.

* How self-fertile (or self-sterile) is A. glutinosa?

I am sure I haven't thought of all the problems which will arise with
actual experience, I will be very grateful for any discussion around
these topics.

Michael Bell

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