You have the absolute best rootstock for flavor and in ground limited space greenhouse growing. I have neither variety so I can't advise you on flavor/time.

SteveR

I have a Xie Shan Satsuma tree planted in the ground down in my wood heated greenhouse. It is on Rich rootstock, is slow growing, but doing very well. It set over 70 fruitlets but after the June fruit drop it currently has around 22 fruit . A number of us GW citrus members have Xie Shan in pots. Hopefully they will chime in. My other younger Xie Shan that was in a pot, gritty mix, struggled more. I will need to look up what rootstock it is on as I lost the tag. It is not a dwarf or rich. The roots were small and not the best when I first got it. I am very pleased with the one planted in ground here in zone 4. MI. Here is a post I started on the Xie Shan last year. Interesting and valuable discussion on it.

https://www.gardenweb.com/discussions/4863491/is-this-xie-shan-fruit-ready-to-pick#n=34

Since most of the fruit are hanging in clusters and growing closer together, they do not have the obvious top knot, only one lone fruit on a branch has it. It will be at least a few months yet, later this fall or early winter, before they start getting close to the ripening stage and I am looking forward to tasting the fruit at different stages to get a better handle on when to pick them for optimal flavor. As a side note, the temperature during last winter in the heated gh stayed between 66-80 during avg. temps in the low 30's to 40's+. We had a few nights below -20 and the gh stayed above 40 degrees except for when the stove went out a few times and temperature in gh dropped to 33 briefly before we got it going again. The only trees affected were the grapefruit and Citron but I watered with warm water and they perked up. A bit of leaf drop but no harm.

I also have a Hirado Buntahn Pummelo on OBO rootstock. It is around three+ years in age and it was grown in a pot, in 5-1-1 mix until just this week, I found a corner spot in the gh to plant it. It did extremely well in a pot with that rootstock and I had to up-pot it twice in the first year I had it but despite being staked it blew over in the wind a few times due to a lot of upwards growth. It is a beautiful tree with lovely foliage and large blossoms that permeates the air. It currently has three fruit holding on that were not knocked off. I will need to keep this tree trimmed well due to the rootstock it is on but thought it would hold onto the fruit better being in ground. Looking forward to getting to taste fruit late this spring/summer if they hold on.

I know I am not much help, but you need to decide which one will do better for you in ground in the gh under your growing conditions. Like Steve said, they are growing on a great rootstock and should do well in ground in the gh, but I do not know what your soil temperature in ground will be during the coldest months, my Satsumas did extremely well during the colder months but this is the first year to see how the HB does in ground on the OBO rootstock. Good luck.

Hirado Buntahn

Great information jinnylea. Thanks for sharing all your experience and the link. It's been so interesting to see the pix of your greenhouse plantings. I planted my oldest in-ground trees five years ago. They're a Brown's Select and an Owari satsuma on FD. They've grown very well, in fact I probably hack off half the new growth each year. They want grow horizontally and I need to train them to grow vertically to keep a small footprint. My ground space is limited because I have lots of other things planted besides citrus. My greenhouse peak varies between 12 to 16 feet so I have room to grow upward.

This spring I took out a ten foot Reed avocado which gave me room for one additional citrus tree. For those of you who are planning a greenhouse I highly recommend that you keep a dirt floor. It's so much easier to care for trees who's roots are in the ground. It cuts down on watering chores---i use a sprinkler to water whole sections of the greenhouse at once. In the winter my soil temps are a consistent 40F, and I water very little.

loneroc1