Denise,
At present I have a Marron medlar that fruited this fall, and a Royal Medlar that was planted just this past spring. I purchased both medlars from One Green World in Oregon.
https://onegreenworld.com/?s=medlar
They were recommed to me me by a friend who runs a nursery in Colorado. He had not planted medlars but he had ordered from One Green World on many occasions. The trees were just bare root whips when they arrived but they grew quickly. The one that fruited produced several dozen fruits in its third year planted here.
Other medlar varieties are available from Raintree Nursery. I haven't ordered from them.
https://raintreenursery.com/collections/medlar-trees
They have done a study on the genetic diversity of medlars. Some differently named varieties are actually the same genetic variety. Others seem to be quiet different genetically. The chart near the bottom of the below link is informative. Having two different tree varieties is not necessary but I figure that it might help to produce more fruit.
https://www.researchgate.net/publication/283330244_GENETIC_DIVERSITY_OF_MEDLAR_MESPILUS_GERMANICA_GERMPLASM_USING_MICROSATELLITE_MARKERS
Some claim that the Iranian medlars taste best. Royal is often called a Russian medlar but the genetics say it is an Iranian medlar. Mine has not yet fruited. So, I am interested to see what differences there are between the fruits of the Marron and Royal medlars. Maybe next year!
I have a small property with limited space for planting trees. If I can find suitable space, I woulld like to add to the Marron and Royal medlars that I now have a Pucia Super Mol, a Macrocarpa, and a Sultan from Raintree Nursery just for the sake of added genetic diversity.
Medlars are a romantic fruit, the stuff of Medieval cloisters. In an age when cane sugar did not exist and only the wealthy could afford honey for sweetening, even a peasant could pick wild medlars from the hedgerows and have a sweet treat at the end of the harvest/winter holiday season. Sort of a fruit cake for those who could not afford cake.
Medlar trees have a very hard wood. They make walking sticks out of medlar wood in the Basque country of Spain. But the trees are said to be vulnerable to wind damage. So I have planted my medlars on the East side of my house with some protection from the howling west and north winds.
In Europe, the wild medlars grow in hedgerows. The wild medlars have thorns and smaller fruits. But all of the domesticated medlars come grafted to rootstock. Medlars do not grow all that quickly and even the old ones are not huge. Judging from photos, a mature tree is in the 20 foot range. And unlike most fruit trees, medlars can live for several hundred years. Like hawthorns, they beome more rustic with age. They become twisted and contorted and their limbs tend to spread horizontally.
My medlar trees are near to my house and I keep them well watered. They say that the young trees should be kept well watered for their first four or five years but then they become drought resistant. Since they are native to places like northern Iran, and grow wild in northern Spain, they would appear to like hot dry summers but also enjoy cold winters. The wild non-grafted medlars would appear to be pretty tough trees.
Planting the medlars wiith their grafts below ground level would allow the medlar graft to root on its own. The root stock keeps the trees at a dwarf size of 12 feet or less. But as noted a medlar on its own roots is not a huge tree. Check out the photos on the Internet. They tend to branch within a few feet of the ground. I planted my medlar trees in raised beds about 18 inches off the ground so that the limbs would be higher and I would be less likely to hit my head when mowing the lawn.
I have a very large red cedar tree within fifty feet of my medlar trees. Trees that are contract apple cedar rust do not surive here. The medlars that I have showed some signs of the apple cedar rust but have not been seriously effected by it. Hawthorns or quince would not surive here. The medlars that I have are most likely grafted on a quince root stock. Which seems to be another good reason to plant the graft underground level.
I have heard that medlars are not easy to grow from seed and do not grow true to variety when grown from seed. But if you have the time and patience, growing medlars from seed might be the best way to eventurally have a quantity medlars that would survive in a hedgerow. The wild thorny medlar fruits are said to be very tasty, just small. But, you should plant a few of the grafted ones first, and see which ones do best or survive in your area. And then maybe you can plant seeds in mass from your own medlar trees.