I recently revisited Dr. John Brown of Houston, TX. Dr. Brown has been hybridizing citrus for more than 60 years. Here is a link to an article I wrote about the visit:
http://okcitrus.com/Another_Visit_With_Dr_John_Brown.html

Thanks for the report on the trees and taste of the hybridized fruit Matt. That is really useful info for those experimenting in hardy citrus whether it be for the actual fruit or strictly ornamental purposes. It's good to see someone take interest in his work and appreciate his passion.

I was really impressed with the taste of his grapefruit/sancitchang hybrid. I spoke to him tonight and he recalled receiving some pummelo or grapefruit from Orlando, FL more than 40 years ago and grew about 50 seedlings. He picked out the 15 best looking seedlings and grew them to a fruiting size. He remembered they began blooming fairly quickly and a few were not cold hardy. Out of the keepers- he crossed them with changsha and then backcrossed those progeny with clementine. He's a little rusty on some of the details- he did not remember poncirus being in the parentage, be he told me two years ago that they were sancitchang hybrids. The leaves were large and have flared petioles. Out of the hundreds of leaves I looked at, I found a couple that were bifoliate. I could not taste any poncirus in the fruit. I can definitely taste grapefruit, mandarin and an orange taste. I asked him how much damage the sancitchang hybrid received in Houston's record low of 5* in 1989. He remembered that it froze back nearly to the ground except for one sprout. The tree vigorously grew back.

That was a great article Matt. Thank you for sharing your experience with us. I am hoping my ClemYuzu 2-2 will bear this spring. I put it on a large rootstock, and it rewarded me with a lot of growth last year. I am also hoping some of the other of Dr. Brown's hybrids that I have will bloom this spring too.

Thanks again, Ned

An idea to the administrators: Why not create a new category, with the headline "Hardy in ground citrus".

There seems to be a growing interest for this topic, it might merit its own category in this forum.

I think hardy is a relative term. Hardy in your location may not be hardy in my location.

Could be solved by calling the category "Temperate climate citrus" as opposed to Tropical and Subtropical citrus. If its very important to define a clear border between the topics, I'm sure some scientific definition of "Temperate Climate" could be found. Say Winter lows under so and so. Alternativley the Hardiness Zones from USDA could be used to define the category. "Zone 8 and lower hardiness zone in ground citrus"

It´s just very different problems we face and different varieties that can be grown in those three different climates, so it would be nice to have a group where everyone facing the same problems and challenges can meet and discuss.

> Why not create a new category, with the headline "Hardy in ground citrus".
I vote for it!

"Hardy" has many meaning and dimensions.

It could be disease hardy, insect hardy, shade hardy, drought hardy, water logging hardy, cold hardy, etc. hardy.

I think the most common association or issue is cold hardiness.

Yes indeed. I have just created a new Hardy citrus forum for USDA zone 8 and below.