Kentucky planting zones don't have much of a range. Most of the state is in 6a to 6b, with just the furthest southwestern region falling into zone 7a. Even the most cold hardy citrus varieties would need to be protected or brought in doors.

This is my 30 gallon Fukushu tree now inside for the winter.

Steve

like  i said any lemons  must  be developed  to take kentucky winters outside

Why can''t you bring it inside.

i don't  want  to i want todevlop cold hardy lemons

Howard is persistent, gotta give him that! Have you talked to the citrus gods lately Howard? You should be asking them to give you a cold hardy lemon for zone 6.

what i found out their is none avalable

 but that won't  stop me

A tree brought in for the winter could provide you with bushels of fruit while you work on developing a Kentukable lemon for outside.

 then i would save the seeds

You got it and you wouldn't be throwing money down the grocery store

  ashland  kentucky is in zone 6b store lemons are designed to be cheap maybe at first  . but after  the initial  tree   production  things would go down

Jorriying Citrus Monster of Manhattan 7b  in
 need to grow  my lemon trees   a store bought lemon is designed to  be cheap  but after  the intial  production of the fruit from the tree it will drop

  im going to keep trying to i secseed against all odds

  im going to keep trying to i secseed against all odds

Store bought lemon are grown on trees grafted to different rootstock than the lemon tree itself. The lemon you eat may have grown on a tree with Poncirus trifoliata roots.

How often to you see winter go below 10F. So far my lowest temperature has been 11F. Last year we had a 4F and 3F nights. Your Zone indicates you go down to -5F. Currently Poncirus Trifoliata is the ONLY citrus tree that can survive that low. I will have picked 74 tree ripened lemons by April from my in ground outside lemon tree.

Only with the help of 4 layers of glass for all glass walls and a low powered fan in the window from the house to the greenhouse. The fan keeps positive pressure to keep cold air from outside infiltrating into the greenhouse.

Steve

 are you sayin i might have to hybridize  ponicirus  trees with lemon  trees to get what i want  but how many generations will it be classified  pure again

You would have to bread a lemon with a PT then bread that again with a PT to get something that can go down to below 0-F. Lemon from the store are cheaper than you can grow them anyway. All citrus fruits are killed below 27F and all citrus takes up to 1 year to ripen this far north. You can grow figs where you live with 3 bags full of leaves to cover the roots in winter. You can buy lemons but you can't buy figs so grow them.

Howard's dream is to develop lemons that can handle Kentucky winters in-ground outdoors. Dreams are like stars. You may never touch them, but just following them can lead you to your destiny.

​ponicirusguy6b452xx  how long  would it be  be fore the lemons would classifide  as true lemons again

Never They would always be 75% PT/25% true lemon. If you planted enough of the seeds You might come across 1 that lost the kerosene aftertaste of PT.

 then  what you are saying  the   it would never be pure  lemons   then it will not meet my needs   i want to  breed  them to be true lemons

Howard you are asking a lot of your citrus. Getting any citrus to grow in Kentucky will be a challenge. Your requirements for an in-ground true lemon might be next to impossible. You should consider which parameters you can relax.

 Horrifing cirtrus monster  of  Manhattan (7 b) 
 i know im pushing  my luck   but i must try

ponicirusguy6b452xx 
that would defeat my pourpuses    so i must back breed lemons to it

several times in winter   here  drops  down to   4 f and 5 f on a regular  baces

I think you have to be able to grow a lemon tree first, so this is a never ending thing.

Howard. These are articles on how to get more from a cirrus tree. While this was done on kumquats, the same process could be done on lemons to achieve your needs.

https://www.researchgate.net/publication/335895525_The_Confirmation_of_a_Ploidy_Periclinal_Chimera_of_the_Meiwa_Kumquat_Fortunella_crassifolia_Swingle_Induced_by_Colchicine_Treatment_to_Nucellar_Embryos_and_Its_Morphological_Characteristics

https://www.sciencedirect.com/science/article/abs/pii/S0304423818307106

Way to advanced for me

It is way to advanced for me too, but this is what Howard needs to do to get his Kentukable lemon.

Steve

I have a feeling that Howard is trying to succeed through sheer plucky stubbornness, rather than scientific methodology.

And that is good.