Paul Haggerty

I am not sure if I count, as I am in a 3 mile wide 5a heat bubble around an airport but should be 4b.

I have Toka and Black Ice plums doing well, the Toka fruits far more than the Black Ice

Erik van Lennep wrote:

Paul Haggerty wrote:I am sort of working on a pipe dream holly breeding project.....
So if you wanted to have a go at doing something similar, maybe some of my planning will help.

Hi Paul, I just saw this posting from last year. How is the project going? I have similar intentions, but for a different climate (Mediterranean Spain). So far I've been unable to find any Ilex vomitoria plants in the EU. Plenty of sources in the UK, but with BREXIT, doing trade with any of the UK nurseries or seed suppliers (or anything at all) is just too costly and cumbersome.

Have you thought of crossing I. vomitoria with I. paraguayensis? Seems at least the chromosome numbers are the same.
If you have the space you might also want to get yaupon seeds from a range of habitats and cultivars and mass-seed them so you have more to select from. Germination will be slow, so that's why you'd want enough space to leave them to their own devices.

Also the JC Raulston Arboretumin N.C: has been breeding various hollies a long time. Have you tried contacting them?

I will have to look into that arboretum. So far this is how things are going:
-> My guayusa plant died
-> The Meserve hollies that I had planted did not survive winter last year (it was a very cold one here in MN)
-> My indoor (during winter) yaupon hollies have also died
-> I am not even sure if my winterberry hollies are alive honestly.

My plans going forward are to order some "Ilex verticillata 'Little Goblin® Orange' (NCIV2)" holly bushes, as from what I can tell, those appear to be tetraploid, so they may have a better ability to cross with another Ilex moreso that the normal winterberry varieties (which would potentially make sterile triploids, but if they survive winter and have caffeine, that works for me).
And of course to order some more Yaupon bushes and try not to kill them. I am just usually gone for a few weeks in November each year on a short vacation, and that combined with my normal forgetfulness seems to be too much drought to handle for them. So I might also try to setup a drip irrigation system for them in my basement ahead of time with some sort of micro-controller so that I can't kill them by forgetting about them.

Edit: had to correct the theoretically tetraploid holly's name

I am sort of working on a pipe dream holly breeding project. I have tried growing tea plants in pots up here, but they need SO much water they always die before the cold gets a chance to do them in.
I have a guayusa plant indoors in my bedroom, that has been alive and more or less happy for 5 years, but those grow in the amazon, and I don't believe modern science has recorded them flowering except for maybe once? They have been cultivated by humans for so long that they only seem to be propagated by cuttings anymore.
So then I got to yaupon holly. I am not as big of a fan of the flavor of its tea as the previous two plants, but it seems the most realistic. I only have to make it jump two and a half zones for my marginal 4b/5a.
At first, based on an old thread on here, I was going to try to cross yaupon with winterberry, since they are both Ilex hollies that are native to north america, and it made sense. So I have 4 female winterberry bushes in my yard now, of two different varieties with early & late flowering.
I then ordered a male yaupon holly (Schilling's/Stoke's dwarf) and put it in a pot, to be the pollinator. It died in my basement over winter. So I bought two more, that were larger, and those have now survived a couple years.
Unfortunately, I haven't gotten them to flower yet in spring, and I wonder if my laziness with leaving the grow lights in my basement on the same timing all winter is making them never really experience spring to want to flower.
So then during all this, I tried to do some research on scholarly articles about Ilex hollies. I was wondering about chromosome numbers and ploidy. These are the numbers I found for some hollies I was thinking of trying to cross to make the mythical zone 4 hardy caffeine plant:

9x4 vs. 10x4
I. vomitoria - 40
I. paraguariensis - 40
I. aquifolium - 40
I. verticillata - 36
I. Opaca - 36

So this makes it look like winterberry (I. verticillata) and yaupon (I. vomitoria) wouldn't be chromosomally compatible, as they have different chromosome numbers. But that might be fine, since the more common chromosome number for hollies I can order seems to be 40.
There are of course some shenanigans that could be done if I was a botany graduate student and not tech support, like using something like colchicine to cause chromosome doubling  in a bud on both yaupon and winterberry, and so then they would go from 9x4 and 10x4 to 9x8 and 10x8, and if there was fruit set, it would have two full sets of genes from each parent, being 10x4+9x4 and going from tetraploid to octoploid (I think?). But I don't have the access to a lab or the know-how to try that.
So then, giving up on the winterberry for now as the female parent, and resigning myself to some lovely stunted looking bushes that will never set flowers without a male of their species, I have moved on to trying common holly (I. aquifolium), or more specifically, a cross-bred offspring of it the Meserve holly, or blue holly. These hollies were bred specifically to survive harsh winters, at least to zone 5.
I only planted some blue hollies this spring, so I have yet to see if they will survive winter in my zone 4/5 marginal area (would be zone 4 geographically, but the Minneapolis heat bubble keeps it warm). One of the blue hollies I planted has already flowered after being planted, so I at least don't need to worry about getting female flowers to produce berries.
Unfortunately, my caffeinated holly breeding project has not yet borne fruit, literally or figuratively. My hope is that my yaupon plants will flower this spring, and I can then do some manual pollination of the blue holly's flowers, and maybe also the winterberry just in case they're not as incompatible as it seems, since holly chromosomes aren't exactly a terribly popular area of research from what I've found.

Otherwise, I am also considering just ordering as many yaupon holly seeds as I can get my hands on, and planting them all over my yard, and seeing if anything survives winter. Because the breeding project will require any progeny that I get between yaupon & blue holly to survive winter, and then I'll have to either find a lab to send them to to be tested for caffeine, or do a caffeine assay on them myself (some google results imply it's an easy college science experiment, so maybe?). And then taking the winter-surviving, caffeine-bearing offspirng, if any exist, and seeing if any of them taste any good.

So if you wanted to have a go at doing something similar, maybe some of my planning will help.