Not sure if you’re still looking for a yellow diploid, but apparently Gold Coin is diploid. It’s ploidy is given in UNDERSTANDING AND MANIPULATING POLYPLOIDY IN GARDEN ROSES along with a number of other cultivars that might be of interest. Particularly if you’re willing to work with triploids too
I’ve not worked with it but it has offspring listed on HMF
Another interesting name on their short list of diploids is Pinstripe. I’m a little disappointed that one isn’t available in the UK. I’m going to have to try Gros Provins Panaché as my diploid striped rose instead
Ruby Meidiand is a pretty good rose. Most of the photos of it online are not actually it. Sadly, there are many red wich types of roses online, including many from Meilland. It gets jumbled up.
It IS a good breeder, and unlike many Drift roses also bred from The Fairy, it does not mildew in the PNW. It is quite healthy and not very large for a landscape rose. To the scarlet, it has a slight orange tinge. Do not use for seed, as its pollen works well enough.
As for Gold Coin, it comes from two lineages where getting more than cream from them would prove an uphill battle. Seems easier to get yellow from heavily saturated triploids. The odds, despite only being 50% diploid, would still be better.
Do you have any experience with Gold Coin? I looked at it’s descendants on HMF and 7 of the 8 listed first generation offspring were yellow or peach. So I figured it was worth a shot. Though I understand that’s a tiny fraction of the likely seedlings from it, it would look to produce some yellow and warmer tones
If you’re looking at Pocock’s Roses for your minis (what a selection!), pay attention to Easter Morning (Golden Glow X Zee) so it’s a cross of the source of the fertile triploids and a remarkable mini breeder and MAY be a fertile triploid itself; Eleanor has generated some fertile triploids when mated with tetraploids; Josephine Wheatcroft is a seed and pollen fertile yellow triploid; Pour Toi is a fertile triploid. You can mine some pretty neat stuff from triploids.
Josephine Wheatcroft looks worth a try. I’m not averse to using yellow triploids myself. But I think I’ll still try Gold Coin too. I’m curious enough about it to give it a try. I have tried Pour Toi in the past. But it didn’t do well for me. possibly a climate thing. Zero seed set and no pollen shed. Cute little rose, but wasn’t usable for me.
Good ploidy link with generalizations I can work with as a hobbyist with hardy species … even if above my pay grade … txs for link.
Expanding, it is pages 52 - 55, and their associated researched based charts, that are worth their weight in gold to myself as hobby crafter.
Use to myself is as a qualitative guide of cross odds and included germination … if you have the ploidy of proposed parents. Of course it wouldn’t bar myself from doing “for a lark” crosses as one contributor suggested great things can come from them … just odds might be lower.
Also learned of another few nurseries (Pocock affiliated) to visit in Kernow when back again for relatives visit - as close by - would not survive in my CDN garden without bales of peat moss protection.
Also found interesting Pocock’s Utube video on budding (on laxa) and growth/ harvesting cycle. .