I saw the 2012 edition of the usda hardiness zone map. Welcome to zone 7, southeastern pa! I do think that your sources overestimated the hardiness of the tx sabal and forgot to mention a couple of much hardier and much more suitable palms for your area. If you want a trunking palm, the windmill palm is generally thought of as the hardiest. For non-trunking palms, the best bet for you (and honestly the only palm i would actually recommend you try other than sabal minor) is the needle palm. As a native of your area i wish you best of luck! i've often wondered how one of these hardier palms would do in se pa.

Texas Sabal Palms (which are either Sabal Palmettos, or Sabal mexicanas) can only survive into the low teens and need a lot of mild temperatures between that to do well so it would not be suited for your area. With the right protection it would not be impossible to grow in your climate, but there are better choices.

Mediterranean fan palms need protection, but they are hardy to around 10F when established (they will be killed below that and damaged once temperatures approach the mid teens).

The best palms for you would be Trachycarpus fortunei (windmill palms), Needle palms, and Sabal minors. Windmill palms are cold hardy to about 5F, mine starts to get damage around 10F, but has seen down to 7F and survived. Needle palms are the most cold hardy palms you can plant and once they are established for a few years, you will not need to protect them (trachys will do best if they are always protected a little in your zone). Some sabal minors are more cold tolerant than others so make sure that if you buy those, you get them from a place that has exposed them to cold winter temperatures.

Since you are in southeast PA, you probably get down to around 1-8F just about every winter which is a zone 7.
Good luck!
-Alex

Texas Sabal is a nice Sabal, one of my favorites for hardiness and growth rate, but there are hardier palms for you. Of course, you could always protect and expand the species but I prefer growing what can survive it alone. Recommend Sabal minor and louisiana (latter grows faster), Trachycarpus fortunei (Windmills), and Raphidophyllum hysterix (Needle Palm). Meds are slightly less hardy, but a good location, good sun and drainage and should be okay. Advantage with both the Needes ad Meds is tat they are clumping--so even if you suffer the loss of part of the clump, should recuperate.

You may be thinking of sabal texensis, much hardier than texana, to around 5 degrees.

Thanks everyone for the comments. Lot to think about.

How do you protect the palm? The area of our backyard where we are considering planting a palm gets full sun from 8am to sunset...it's a south-facing backyard, with no overhead obstruction whatsoever.

Only reason we want to plan a palm is that we are building a pool (life-long dream, finally realized), and thought a palm would be a perfect complement.

Stick with a windmill palm. It'll still need protection in your zone, but will do much better.

There are a ton of strings on palm protection here. Personally if its anything more than wrapping the heart in burlap when it gets too cold its just not worth it. Windmill should be ok down to about 15 with no protection and somewhere in the upper single digits wrapped in burlap. From my experience you want to keep it free of debris like leaves.

Our house is 10 miles S of the Mason and Dixon LIne, but we lived in SE PA for years. SE PA covers a wide area from just w of Elizabethtown to Easton and southward with lots of warm and cold sections. The Bethel-Shartlesville-Hamburg- Lenhartsville section is the coldest with annual lows about zero to the South of Highway 1 area south-southwest of Philadelphia and southward is the warmest with annual lows of about 4 degrees f. Another factor where it is hilly is not only your elevation, but your exposure to winds and whether you are on a S or N facing hill. Crape Myrtle and Southern Magnolia grow well. Willow Oak and loblolly Pine can be grown as well. Palms, other than needle palm are a very poor investment. In Delaware and eastern Maryland and NE VA (above Richmond) Needle palms and Sabal Minor (in the warmer sections, not colder sections like northern Harford County or northern Baltimore County,) are your only feasible options A few hardy varieties of palm can be grown along the shore areas of Delaware, Maryland, and Virginia (with annual lows near 10 degrees.) Southern live oak can survive under the same conditions as needle palm, but will freeze to the roots until established, and will defoliate/ or partially defoliate in harsh winters. We plan on planting three live oaks at our house in west-central New Castle County, along with several needle palms.

I live in a suburb 10 miles due south of Pittsburgh and planted a Sabal Minor and a Palmetto last June and they went through this past very harsh winter with only a little damage, its now June again and they are putting on new fronds fast. I planted them on the south sunny side of the house where they are mostly shielded from the dry cold wind from the north and west in the winter. The only protection i gave them was i built a small cage around the Palmetto with some mulch and put a heavy duty blanket on the cage and the Minor since its more cold tolerant i just mulched it and put a cardboard box on top. The cold tolerance of the Sabals just amazes me, now if you go 50 miles north of Pittsburgh I wouldn't even try growing palms, but we get the heat island effect which helps a lot, plus having the 3 rivers closeby helps too. I also have a Tonto Crepe Myrtle which has made it through 2 winters already with no protection, it actually has just started growing in the last 10 days, it was really starting to worry me.

http://www.bg-map.com/hardiplm.html

You've probably already been here, but here is a person in your neck of the woods that did exactly what you want to do. Personally, the only palms I would try there would be sabal minor (the variety from south central Arkansas, or 'McCurtain') or Raphidophyllum hysterix (Needle Palm). The particular ecotype of sabal minor will make a difference.

I would also suggest some kind of overhead canopy that doesn't lose its leaves/cover in the winter. Something like a spruce. Trim all the branches up to 5 feet (more as the palm matures) to allow sunlight to get to the palm, but overhead cover to keep the snow out of the crown. If it gets brutally cold, it will also serve as an extra layer of protection when you cover the palm with blankets, etc.

Good luck with it!

Palmnut-please join us on the Hardy Palm and Subtopical board

http://members3.boardhost.com/HardyPalm/

the Hardy Palms in Temperate Zones board,

http://members3.boardhost.com/MIDWESTPALMS/

and the Hardy Palms for the Northeast Board,

http://members6.boardhost.com/spanish2/ .

I like this board, however, these other boards are much more local and are more relevant to us here in Pittsburgh. No iffense to anyone here, please feel free to join us as well if it applies to you!

My S.Palmetto just today, put on 2 fronds last year, now has 3 going for it, just saw the 3rd one pushing up this morning.

My S.Minor, jut starting to put on fan leaves in its 2nd year in the ground here.

My CM last year