I back I had to get a new phone

Frankfurt Ky A bit warmer than before and if you are in the city center you are now zone 7. The answer is still no. You will need 200 frost free days and temperatures no lower than 25F for tree health and survival. The fruit will need 300 frost free days to ripen with temperatures no lower than 28F. You need to develop fast growing fruits as well as a -1F tree.

  I will try any way

I was wrong about the zone it's still  6b  but  I'm still going to try any way with out trying  nothing will ever happen

 Are you saying  if I want  a citrus to meet my needs I must devlope it to handle my conditions

Yes or you will need a greenhouse or indoor lighting

 But I will still slowly develop them  to take more cold than normal

 Ok I will develop them for my needs and  conditions   but I must be very selective on Wich  trees I keep

You cannot "develop" citrus trees to meet your conditions.

   I believe it can be done  but it will not be easy  through careful selection  then how do you  explain the  cold tolerance of the Harvey lemon that  is more  cold hardy than other lemons

Do let us know how it works out for you.

It has been done. A mutant eureka "grocery store" lemon came up from seed that has turned out to have tolerance down to 10F. when it is grafted onto Flying Dragon it can get down to 5F as long as the dew point is no lower than 5F. Lemons. Lemon tree grafted to FD produce more juice as well as lemon flavor than those you buy at the grocery store. Those lemons are grafted to lemon tree rootstocks than produce more lemons with less flavor at an earlier time. $$$$$$$

Steve

 U guys don't  get it I'm going to do it with out flying  dragon  because  that Is not what I want

 I'm not going to use  flying dragon in  breeding stock because that is what  I don't want

Using flying dragon as ROOT STOCK has no affect on the breeding of your lemon. flying dragon pushes the lemon tree into dormancy and holds it there until it is warm again. Keep working on a cold hardy lemon but when you develope 1 that can go down to-5F you can grow it on Flying Dragon roots in ground and use seeds from that tree to push on.

 But to me that is  a lie to developing tru cold hardy lemons  

Howard

I don't know why people bother here, Howard has no interest in anybody's advice and is determined to do it his way and only his way. I'm not sure why he asks questions when he has zero interest in what anybody has to say. Howard, why do you keep posting here when you get the same answer from everyone but still insist you can do better when your trees continuously die? And please stop posting selfies of yourself. Nobody wants to see you, post pictures of your trees.

 Well  right now I have no trees  but I'm s see

  Ken B Zone  7 the reason Yu are not seeing my trees  is right now I have none and apparently I must strike some interest  or they would not bother  and    some where some thing is being missed in the translation  because I'm  not going to us flying dragon and that's final

Howard What you don't understand is that a citrus capable of surviving -5F is still a subtropical tree and cannot survive over winters as long as yours are with out grafting it to a deciduous root stock. Citrus trees store their energy in there cambiums will deciduous trees store their energy in their roots, PT is the only citrus that is deciduous and will have that extra supply of energy in spring. Your cold hardy citrus will DIe. Without PT/FD

Than it must be developed  apparently some where  they apparently have   the  potential to  to  be developed to do so   sorry we dissagree there because  I understand what you are  saying but  no one is willing to  accept citrus can be developed  to handle  winters out side  in 6b   but finding the right mutations  in lemons is hard I guess that's something is not uner stood  and that's on their own own roots     we must agree to disagree on that part  but we both can agree  to find those mutations  can take time and th are not common

 Howard

 If I understand u right I my as well  breed  The lemon  with flying dragon and  back cross with  more lemons

 Grafting on to another  rootsock to me making true cold hardy lemons a lie because  the seeds would not develop the true cold hardiness I need

  Ponicirusguy6b452xx  then if I understand u right to get what I want I must  breed flying dragon  with lemons  and  back cross with more lemons

Howard

 What If turns into a Chmerea

What if wishes were fishes and the world turned to candy (about as likely I'd say). Howard, it's occasionally amusing (that's why I continue to read), but geez they're right. You're living in a fantasy world and apparently no one can change your mind.

Here's a list of cold hardy citrus, start there, or just move along and stop asking the same question every X days. Lemon is not on the list, it doesn't have any such genes in the gene pool so you can't breed for it using only lemon, or we would probably be pulling up lemon seedlings in Kalamazoo Michigan today growing out of cracks in the sidewalk.

https://en.wikipedia.org/wiki/Cold-hardy_citrus

If there were already cold hardy selections of lemon, you could start there, but it doesn't exist. You can't select for a non-existent trait.

You'd be about as likely to develop water-breathing poodles by putting new born puppies in an aquarium and putting a lid on it so there was no air surface under the lid. Expected result: All puppies die, because the trait of water-breathing is not existent in canines of any species. Admittedly some of their ancestors were fish, but I think they lost gills a long time ago.

  Poodles are a  type of hunting  dog   that retrievese small game v from water

 Not fish

  Some times a chemirra happenns when a graft down' t fully take   and then  the plant    breeds with  graft

 Apparently those traits  exist   and If they  didn't the Harvey lemon  would never had  happened even though it's from unknown parentage    I May have to start with that  variety  and keep  pushing for what I want

 Ponicriusguy6b452xx

 Some times a chimera   happens  when a graft don't fully take   and some    breeding from    the host tree  And some  separate  and some  where the host secesfully bred with host tree

The harvey lemon may have flying dragon in it's background, no one knows :)

  This comes from hidden genes nobody knows about 

 Howard

There is no such thing as a species known as lemons. This is true of most citrus being a mishmash hybrid.

A genomic study of the lemon indicated it was a hybrid between bitter orange (sour orange) and citron.--Wiki

In another 100 years or so, the combination of selective breeding and warming temperatures may make a true lemon tree hardy in zone 6B Kentucky a reality.

Unfortunately that will be too late for me and Howard. :(

  A bitter orange  is  flying dragon

 Rusty I believe It can be done sooner    but I must start with the coldest hardy lemons of today  and push them for even  colder  cold hardyness nobody said it was going to be easy

 dbrron see  there are still some genes we know nothing about 

Howard

Fun thread! Let us know how you do.

https://www.frontiersin.org/articles/10.3389/fpls.2020.01234/full

https://en.wikipedia.org/wiki/Cold-hardy_citrus

  Partim  they seem to think  that only way  to get cold hardy lemons for zone 6b is to use trifoliate  genes  but still think it can be done other wise  are you  with international citrus growers

Nope. Retired banker. Botany major way back when.

  I know I'm different than the rest on this forum  but  believe   that true cold hardiness in lemons  are in the genes

  That my be so ,  this is the classification  of true lemons

Howard

Cold hardiness is definitely in the jeans

shown by this model.

My uncle had a fruit farm in Niagara, Canada. Mostly peaches, some cherries and a lone apricot tree just for fun. The apricot was the least cold hardy. It didn't die in cold winters, but most years there was no fruit, because once the buds had broken their dormancy and started to open, a late frost would freeze the flower buds dead. And in some years a late frost killed all the cherry flower buds too.

http://omafra.gov.on.ca/english/crops/hort/news/orchnews/2014/on-0214a1.htm

 I was not talking about that type of genes   it is   in the genome  of lemons it has  get developed  and expoliotesd

  I have no access to flying  seeds and what  If the graft doesn't 'fully take  then  the lemons and flying dragon  will breed  to each other 

Howard

  I have no access to flying  seeds and what  If the graft doesn't 'fully take  then  the lemons and flying dragon  will breed  to each other 

Howard