I kinda answered your other post, but this one for the same info has more info from you. You may have just resolved the problem with yellowing. TOO MUCH WATER! Watering 2 to 3 times a day is WAYYYYY too much. MAYBE... and I am going on my own experience here, 2 to 3 times a week, give a good deep watering. You mention the soil is very sandy. While the palms do like sand to a point, I'm wondering if there's too much sand. Perhaps it might be a good idea to dig them back up and amend the soil a bit with some small wood chips, composte, top soil and vermiculite. I have found that the palms seem to like this type of soil. They don't like to be wet all the time (caused yellowing and can cause weakness then death), but they also don't like to be dry all the time either.... and less so before they are established. Just some thoughts there. ):)

I heard about a windmill palm surviving in the brooklyn botanical gardens. I found that pretty cool even though they do protect it, it does show that some people have a knowledge of cold tollerant palms in a zone 7. I also heard of a needle palm surving without protection in the new york city botanical gardens. In my area their arent any palms in the ground that I know of that are surviving the winter except for one windmill palm on someones front yard, but Im not sure if it has actually been through a winter yet, but I do now their was a washingtionia in its place a few years ago when I past their last. Also definately some musa basjoos around the area that are quite large, and also TONS of southern magnolias some very large and covered in blooms from may to july. Good luck

Also, try not to get too heavy of a blanet. Just a light blanket that keeps the air flowing, but some extra heat in, is good enough! My meditteranean fan palms didnt have a scratch on them after this past winter low of 7F with just christmas lights and a garbage bin (no frost cloth like some of my other palms). Mediterranean fan palms are really only hardy to about 15F or so before damage begins so Im sure that it was pretty comfortable in there for the palm. Windmill palms are even more cold tolerant so even no blanket should work in your new zone 6, if your worried about the fire hazard (and the thermocube is a great idea!). I dont think Coconut palms are pushing it in a zone 9b, because usually, they do really well (I've seen coconuts with fruit on them in Orlando before). The past 2 winters in Florida have been way below usual and thats why tropicals are dying off fast! The city of Orlando is probably more of a zone 10. Even with these past 2 record breaking winters, Orlando only went down to about 28F which is just shy of a zone 10. With Protection during the worst of winter, maybe 2 out of 20 years, coconuts would do great in Orlando, but fruiting isnt likely so they are definitely a marginal palm in a zone 9 and really need zone 10b and up to do there best (Miami/Fort Lauderdale area and south to the keys is safe for coconut palms) And you wont regret getting a remote thermometer! I had one in my pindo palm shelter for the 1st year and it was really helpful in determining when it was too hot or too cold in there (fortunately it never did get too cold). You dont want your palms going above 65F in the winter because then it will start growing again and new growth is always very tender to things like cold (that goes for most plants, but palms only have one growing point!) -Alex

I will try to answer your questions with what limited knowledge I have. Planting the Palm in the picture with the black plastic and rocks was not intentional on my part. I had put the plastic down and the rocks a few years before I even planted the palm. If I had taken the picture at a different angle you would see the pool that is close to the palm. I put the plastic and rocks around the pool to help keep the pool cleaner by not getting all that grass in the water. But I do think that it does help with keeping the palm a little warmer in the winter. The rocks would absorb heat from the sun and the plastic would help some to insulate the roots a little better. The other two windmills I have are mulched but the one in the picture never has been. The two other palms have not grown as fast as the one in the picture. The question about how big the hole I dug to plant the palm in. The answer is I double the side of the root ball in depth and in length. I used plain old potting soil "without any fertilizer", with some peak moss and a little bit of sand. I did not give it any fertilizer I used Superthieve with every watering for the first three months then I used mild amount of Miracle Grow. Question... the nursery that I bought them at told me to snip the outside fans in order to induce faster growth, I notice you haven't done that. Snipping the outsides, also gives more of a traditional palm look to it, wouldn't it. I have never heard of this before, I canÂt image cutting off healthy growth to make the palm grow faster. If it was me and you just planted them they are stressed enough already I sure would not be cutting on them. Over time the bottom ones will die off anyway. Protemp, I keep six Windmill in the house all winter they are pretty easy to care for just mist them keep them watered but not wet and place them where they will get some sun. neofolis, I think someone else has already answered this but we do have a long hot summer. I saw an interview with the Princes the other day on NBC and I noticed a Windmill Palm in the back ground how cool. I hope I have answered all your questions sorry it has taken me some time, I have not had the time for a reply.