Lets see we have three types of plum trees, one peach variety, apricot, pear, two types of apple, two types of cherry for our fruit tree selection;
Black Walnut, English Walnut;
Pin Oak, red maple, sugar maple, birch, poplar, dogwood, cherry, black locust;
white pine, blue spruce, arborvitaes.

I think that about covers it. We do try to diversify, to plant trees that are productive fruit wise, wind blocks, specimen trees and some just because I like the look of them.

I have two acres of what was part of a tobacco farm, with no trees anywhere. I immediately started planting cypress trees facing the road, and along one side of my property, 58 trees in all. Then I spread around sugar, silver & crimson maples, pin & live oaks, tulip tree, arborvitae and a sycamore. Surprising to me that the live oak and sycamore have grown the fastest, along with the cypress, which are known to be fast growers. I had a couple others which were run over in mower accidents when they were first planted.

One of the first thing we did was put in the fruit trees. Oh, and a willow I forgot to mention, I like the look of them. We have a pin oak out front that is ancient..it takes three people to put their arms around the trunk. We planted the sugar maples, had one hundred saplings, many died a natural death, some were under the deck of the lawnmower before I saw them (my bad), I guess have about 30 of those left in what was an old pasture. In all we have just under 6 acres, plenty of room for trees and two big gardens. It would be daunting to start from scratch though. At least most of our trees were already on site when we moved in. We did thin out the locust for firewood.

three kinds of Pinon Pines, 3 fruitless mulberries, an apple tree, around 30 Doug Firs and my pride and joy, a Chitalpa (hybrid desert willow)

this isn't my tree, but just a stock pic

It was a really nice tree, but it fell over. We let another trunk grow from the base and it was about 8' tall when it fell over. I'm thinking of ripping the whole damn thing out and putting in something stable.

The poor cherry tree was planted in a shallow bowl lined with shale (most of our yard). It fell over in a wind storm and it took my father's F-250 and the neighbor's Chevy SUV to pull it back into position. I think it made it. There are new sprouts and buds all over the thing. That would be good.

it is triangle shaped----looks like a piece of pie. There is an empty field beside me and they were never willing to sell it to me so I could have a decent amount of land.

But even with that, I have several trees, along the property line. I have three huge (100 plus years old) pin oaks. There is also an ash, and I am concerned that it may have a problem with emerald ash borers. And there is a Norway Maple. With all these trees being mature, it is hard to plant any other trees since it is all so shaded. I do have a Sassafras tree that sprung up and is about 20 feet tall already.

The only trees I would be able to plant are shorter, understory trees, and I have been considering Witch Hazel and/or Serviceberry. But it is a tough yard to get plants to grow!

I am defining "tree" as something with at least the potential to achieve a decent size, and the potential with proper training to grow in a tree-like form. I am excluding things that are exclusively "shrubs" such as forsythia, common lilac, etc.

So far, I'm up to 111 species (not varieties/cultivars) on my property. This was done from memory, so I need to check my list against the real world when time allows.

It was at one time part of an orchard. From the orchard we still have three avocados, two fig trees and an apricot tree which volunteered after a very large apricot tree that was on the property when we moved in died. We also have at least two pomegranate trees or bushes (not sure which they really are). Finally, we have two rather large ornamental trees, but I don't know what kinds of trees they are.

I woke up one recent morning to find that the inner core of one of our avocado trees had rotted and that the rotted core had fallen out of or oozed out of the tree. So now we have a hollow tree. We aren't certain what to do about it.

holly, oak, hickory, dogwood, sourwood, maple (red and sugar), sycamore, poplar....every kind of Eastern hardwood. Cedar, laurel, apples and white pines.

The favorite are the hemlocks, though the woody adelgid (sp?) is killing many. One of mine is 40 ft tall, another around 25 ft and one I transplanted is now my height. I want to transplant more (there are babies all in the woods) but I am afraid of the WA, so I am considering another evergreen as a screen.

Great question.

Edit to add: the previous owners put in a bradford pear, which i (hate) and will cut down this year....too much risk as it is next to the power line.

Tulip Poplar
8 Norway Spruce
Purple Robe Locust
Sunset Maple
Forest Pansy (type of Redbud)
Blue Spruce
Curly Willow
Redbud
Dawn Redwood
3 Wild Cherries
Shagbark Hickory
Kousa Dogwood
Flowering Crab
White Birch
Sweet Bay Magnolia
Katsura (third year)
Franklin Tree (new)
2 Dwarf Peach (new)
Seven Sons Tree (new)
Japanese Red Maple
Yoshino Cherry

We had two native elm trees that we kept alive until four years ago. That broke my heart!

Some of the shrubs we have around could probably almost qualify as trees!

BTW, the Katsura really is as lovely as they say. I'm not sure where you're located, but its' growing well here in SW Pennsylvania.

We're always looking for new things to plant.

Let's see, when we moved in 3 years ago, we only had:

-red pine
-dwarf white spruce
-lilac
-silver maple (these will be removed in the next 5-8 years)
-white poplar (these will also be removed in the next 5-8 years)
-one apple
-chokecherry

Since then, I've added:

-pawpaw
-persimmon
-more apples
-medlar
-yellowhorn
-dwarf cherry
-hybrid Japanese plum
-seven-son's flower
-black chokeberry
-hybrid chestnut
-apricot
-hazel
-walnut
-juneberry
-honeyberry
-rugosa rose
-sea buckthorn
-Cornelian cherry (actually a species of dogwood)
-red-twig dogwood
-arborvitae
-anise magnolia

AND, I just sent in another mail order for 40 more plants of 20 more species of fruiting trees and shrubs this weekend. I also have hundreds of seeds stratifying in potting soil in my unheated garage for spring planting, including 200 hybrid chestnut seeds and 50 Russian walnuts. My ultimate goal is to have as many edible trees and shrubs as possible on my land, both for human and animal consumption, and give away the excess I grow from seed and cuttings to neighbors, friends, family, coworkers, etc. Most of the plants I have are still relatively small (nothing I've planted is over 6 ft yet), since I saved money by purchasing smaller saplings via mail order/Internet or growing from seed, but I'm a patient man.

Juniper, two kinds of pine, a fir, a hawthorne, aspen...and some fruit trees, which I didn't count.

mulberry, mimosa and native willow trees that grow like weeds. There are also a couple of oak seedlings that have sprouted in my flower beds that kept their leaves all winter and are now putting on new growth. I would like to transplant them, but I've heard that they have such a long tap root that it's very hard to do this. At any rate, they are not in good places and will have to go away, one way or another.