Hey, James, sorry for the delay--I only just saw your question.

From what I can remember, the original discussion was on the MPG forum. Or maybe another gardening forum like an old Yahoo group (my memory stinks, sorry).

My very first plumeria--in 2005--was a Singapore cutting gifted to me from friends who got it from Aloha Tropicals (or some similar name). Anyway, it was long before I knew what I was doing but I managed to root it and from Year One it black-tipped on me. Never did bloom, though I made cuttings and new plants from it, trying in vain to give it a better shape. This is one of those that grows outward and low. Most of the new branches that came out after black-tipping would grow at almost 90-degree angles.

Then I read years later (maybe on MPG) that there are two distinct types, the upright and the bush-type. They even included great pics as examples of each. This is when I started wondering if both types black tip. There's a guy northwest of me, in a slightly colder area of Texas, that has a beautiful Singapore that blooms for him, with no issues, so it can't just be that all Texas Singapores have that problem.

I ended up giving away the two remaining Singapores in hopes that the next owner would have better luck (and in case it's just my yard that has terrible Singapore mojo. I'm not exactly known for my ability to make plumerias bloom, LOL.)

Kms2 has one of the original starts from that Singapore and he eventually got his to bloom through a black tip! He says it still has a weird shape.

Anyhoo, hope that answers your question! If not, then I'm sure someone like Doug or Jennifer at MPG must have the scoop on the Singapore issue. Good luck, my friend!

Jen,
I have seen a more vertical growing singapore near my patch, it was a huge tree. I knocked on the old Hawaiian dudes door to ask if his Singapre ever got BT, he didn't know that it was so I explained. I was told by him it never had that issue, this was Aug 2006. In the Winter of 2007 is when we had the huge freeze with severe losses. I went by the Hawaiian dudes house to check out his Singapore and it had was not spared from the cold. I noticed the owner trimmed back the damage and tree, noticed that there were new branches that had started also. I haven't been back since that drive by summer 2007. I kind of feel like going by to see if his tree truly recovered or if that cold spell pushed it into the BT zone.
What ever happened to Labland (sp???) She had a Singapore White in La Verne and she stated she didnt have BT either and it gets cold, cold, cold in the IE during winter.

I noticed also on "The Valley of The Sun", Detrick posted a pic an old, large singapore white growing in front of a hotel. I also noticed that the growth of the Singapore was verticle and more compact. I guess I'll have to hunt for the illusive non Black tipping verticle Sing.

Jen I have a large Singapore Obtuse and have never had trouble with black tip I think it may be the dry heat they like it dry and hot

The biggest Plumeria I ever saw was a S.O. on Kauai that had to be about 35 feet tall and maybe a 3-4 foot diameter trunk.

IMO I am leaning towards trying to see if a dry spring is better for S.O. Spring is traditionally the rainy season for both Jandey and me. No doubt a dry spring didn't happen this year.

Perhaps I will leave it in the greenhouse longer next year and keep it dry to see what happens. I had it so dry it was wilting in March but then pulled it out f the greenhouse and its been receiving steady rain and has black tipped.

Interesting about the dryness factor, as that was a comment from the Phoenix growers: they like it really dry. Supposedly there's a big Singapore there that does very well.

However, the guy I know who has one is in the hill country, where they're just as humid as Austin, just about 50 miles northwest of us.

James, maybe the coastal areas of CA are not good conditions for Singapore. Is you patch more inland?

Jen,
I posted about an old Hawaiian guy who had a HUGE old Singapore that was vertical growing, until the big freeze of 2007. He told me he had never gotten BT and he is in the same costal area where my patch is, I guess he must have a different Microclimate as I did not have any cold damage on my plumies. I know in Miami I have seen some huge Singapore whites with no BT damage and its wet and humid, I was in Miami one June and it rained everyday for 2 1/2 weeks (only had 3hrs of sun the whole time), but it was hot and humid like hell.

Jandey1 I have sent cuttings from my Singapore obtuse to the Dallas and the Austin area and they did not do well I really think it has to be dry like Phoenix I live in west Texas where it is real dry and I have no trouble with mine.in winter I keep greenhouse in the 80 so it stays warm all year

So the Singapore "Will It/Won't It" mystery goes on! So some will not black-tip in even humid and rainy areas while others will. I think that supports the two-different-strains theory.

Katie, thanks for the info. Do you remember where yours came from originally?

Jandey1. No to many years ago. But I think it may have been 1- stop- ahola . Or Jim little not sure.