Well, it depends on how far west you are. The farther west you are, the fewer trees that will do really, really well. I've linked a publication that lists some trees recommended for Oklahoma. If you are in extreme southwestern Oklahoma or extreme western OK, you might want to check with your county agriculture extension agent to see what grows well there. Trees that are generally recommended for NE Oklahoma, for example, probably are considerably different from ones that would grow where you are. (Considerably different soils and rainfall.) Here in south-central Oklahoma, I spent time studying and identifying the native trees before I decided what to plant in our landscape. Many of the trees that grow well in south-central OK probably would grow well in southwestern OK, too, though they might not get as large. Here's some trees that are native or naturalized in southern OK: SHADE TREES: Hackberry (Celtis laevigata) Texas Ash (Fraxinus tesensis) Bur Oak (Quercus macrocarpa) aka as mossy-cup oak because of the mossy fringe around the edge of its huge acorns) prefers moist forest-type areas, but is growing well in our thick red clay soil with a pH similar to yours, and it has huge leaves. It is a slow grower the first couple of years, but then really takes off. Post Oak (Quercus stellata) Very solid-looking trees with fairly short stubby branches Shumard Red Oak (Quercus shumardii) LOVELY red fall color Kentucky Coffee Tree American Elm (Ulmus americana) larger leaves, long-lived Cedar Elm (Ulmus crassifolia) smaller leaves Texas Persimmon (Diospyros texana) Wooly Bumelia Eastern Red Cedar (Juniperus virginiana) VERY adaptable and almost impossible to kill(invasive water guzzlers) Willows and Cottonwoods--on creekbanks and pond edges Honey Locust Pecan (Carya illinoiensis)(esp. in river bottom areas and in deep soil) Sycamore Osage Orange Honey Mesquite (Prosopis glandulosa)(deep-rooted and very drought tolerant but only make light shade and I don't know if they are available commercially) Catalpa UNDERSTORY TREES: Possumhaw Holly (Ilex decidua) (shrubby tree) Redbud (Cercis canadensis) Rough-leaf Dogwood Mexican Plum (Prunus mexicana) Rusty Blackhaw Viburnum (Viburnum rufidulum) OTHER TREES THAT MIGHT GROW WELL IN SW OK: Desert Willow (Chilopsis linearis) NOT a true willow and NOT actually a desert tree, but it does best in really well-drained soil. Very drought-tolerant and has few pests that bother it. The flowers are tubular and quite lovely...a pale lavender on the native one. One named selection, "Bubba", has flowers that are a dark wine-purple and is more compact than the native. Other selections include "White Storm" and "Burgundy Storm". This is a member of the same family as the trumpet creeper vine. Chitalpa "Pink Dawn" (Chitalpa tashkentensis "Pink Dawn") is a hybrid of catalpa and chilopsis. Very well-adapted to hot, dry climates. Crape Myrtle (Lagerstroemia)--Deciduous, flowers, needs irrigation in dry spells. Comes in all sizes, from small weeping ones to very tall tree-like ones. Southern Wax Myrtle (Myrica cerifera) Actually a very tall shrub, but can be pruned up tree-form. Tolerates almost any soil conditions, but may need irrigation in dry periods. Handles slow-draining soil really well. Chaste Tree (Vitex Agnus-Castus) A tough deciduous shrubby-type tree that can eventually get about 20 feet tall. Will spread out pretty wide, but you can prune it up into a tree form. Flowers are generally blue, but there are pink-flowered ones as well. Butteflies love them. Very drought tolerant. Windmill Palm (Trachycarpus fortunei) One of the more cold-hardy palms, but may not survive in SW OK. Survives without irrigation once established except during very dry spells. If you are very far west, you might need trees that are more commonly found on the High Plains of West Texas, and there aren't a lot that I can think of off the top of my head. Your annual rainfall as well as how much you are willing to irrigate will help you determine what to plant. If you get 30" of rain a year, or you're willing to irrigate up to that level, you have more options. If you get 25" of rain a year, you have significantly fewer choices. When annual rainfall drops below 30" per year, natural woodlands begin to disappear. If you soil is sandy to sandy-clay, that is better because water soaks in deeper to get down into the root zone of trees. If your soil is very thick, very dense clay, it will be hard to water trees deeply so you'll need trees than can thrive on little water. Mesquite, mentioned on one of the lists above, would be one tree that could handle very little rainfall. Mohr Oak (Quercus mohriana) aka Shin Oak This is a small live oak that is very drought tolerant (but not as drought tolerant as Vasey Oak). It grows in sand, sandy loam, caliche clay and on limestone and needs well-drained soil. Is a small tree, only getting 10 to 20 feet tall at maturity. It likes to sucker and form colonies. You can get a larger tree by pruning to a central and leader and letting the tree put all its energy into that one trunk. In very sandy soil, it can stay as short as 3' at maturity. Western Soapberry (Sapindus drummondii) In very dry soil it will mature at 10-15 feet but in wetter conditions it can get as tall as 40 to 50 feet. Has lovely fall color (yellow) and the berries (amber-colored) are very attractive to bluebirds. Prairie flame-leaf Sumac (Rhus lanceolata) aka Lanceleaf Sumac. Grows well on limestone and in calcareous soils, including sand, loam, clay, and caliche, but it needs to be well-drained soil. Provides very vivid fall color and tends to get 10' to 20' tall depending on the annual rainfall. Makes a gorgeous contrast to western soapberry in the fall. It also provides food for a lot of bees, mammals and birds which can be very important in western parts of the state where food can be scarce. Harvard Oak (Quercus havardii) aka Shinnery Oak or Harvard Shin Oak--it is really a tree, but a very short one. Maxes out at 2' to 3' tall but can grow in the driest conditions imaginable. Once it is sort of old (4 or years old) it will begin to sucker and form a thicket. Ashe Juniper (Juniperus ashei) Gets 15-20' tall and grows in well-drained sand, loam, clay or limestone. Has a shaggy bark that peels off in long strips. Very dark green foliage. Rocky Mountain Juniper (Juniperus scopulorum) Gets 30' to 35' tall (eventually). Slow-growing but is very long-lived and tolerates tough growing conditions. Oneseed Juniper (Juniperus monosperma) Gets 15 to 20' tall, and grows in any well-drained soil. Probably the most cold-hardy juniper. Silverleaf Mountain Mahoghany (Cercocarpus mntanus var. argenteus) Usually grows about 10 to 15' tall and maybe a little shorter in very dry sandy soil in a hot climate. Has dark green leaves (on top)with a fuzzy silver underside. Very slow growing. Very hard wood. Tolerates drought very well and grows in any well-drained soil. Colorado Pinyon (Pinus edulis) Is a pretty short tree (around 10' tall) that can eventually reach 20' if well-irrigated. Grows in any well-drained soil. Extremely drought tolerant. Cottonwood (very well adapted to dry western areas but not used in home landscapes much....just thought I'd mention it, but I wouldn't recommend it because it tears up sidewalks, roads, foundations and plumbing lines). Now, if you have two acres and could plant it far, far away from the house, it might not be a bad choice. This is a very long answer and I hope the info is helpful. I'm too tired to proofread it for typos, so please forgive any you find. Dawn Here is a link that might be useful: Trees for Oklahoma

Thanks again everybody! Tropicalzone7- I've had the queen palm for probably about 5 years. When I got it, it had large strap leaves and was about 5 feet tall. I thought it was a coconut seedling at first until the leaves started to feather out. It doesn't always have a full crown, but I'm hoping as it gets older and larger, it will have a more consistently full crown. Bradleyo- No I don't overwinter the Philodendron in the ground. I actually have 3 and I dig them up in the fall. I'm thinking about sacrificing 2 of them and keeping the one developing the trunk just to reduce numbers. I have too many potted plants. The Butia is first year in the ground. I got it as a blue pot palm from Kmart, along with 4 sabal minors and 2 needles. Those are all new additions this year, and I'll probably protect all of them with styrofoam rose covers. My one sabal minor did great with that method. No heat needed. The larger 3 trachys and Dracaena are protected with structures and christmas lights. The 3 needles and trachy planted in the lava rocks against the brick survived winter with only burlap wrapping due to good siting. The reason the Trachys look different health levels is because the plastic bag I use in the winter tore in strong wind, letting cold air into the structure, killing the foliage back on one of them. The largest one was purchased from a member who had it in ground and it defoliated, so it's still recovering and establishing itself. The smallest of the 3 looks the best(the one that had trunk rot) because it's been in the ground 5 or 6 years and it's established and now growing new fronds fast. Plantsaremylife- Thanks for the compliment! The bamboo is Yellow Groove bamboo. The pictures don't really do it justice, it's probably 12-14 feet tall and grows like a weed. I also have a few Fargesia Rufa, but they take forever to get any size to them. I use the Yellow Groove to screen out the neighbors. There are other varieties of running bamboo you can grow, Bissetti is one I can think of, but I think yellow groove gets bigger canes.

Wooroonooran - thanks for your tips and i will most definately be keen to try a native Messua. Do you know what species it is and what its requirements are? Ari - I am yet to get an Amherstia. I have one on order through Arnhem Nursery but it wont be available until May/April. I have a rather large African Mahogany that casts shade over half the garden and ataht is where I think I will plant it. The Messua is going under a big Euodia. Some magnolias do flower well here - I have M. coco (not to be confused with Michelia figo 'Coco') with its nodding and night scented white flowers doing extremely well. I have trialed a few other magnolias with varying success. A range of Michelias do well here of course as well. The trick is to find a species that comes from a low elevation tropical region, and there are many species of Magnolia that come from those climates. The real difficulty is sourcing these plants in Australia. Mangletia is closely related to Magnolia and does have evergreen species from tropical and subtropical areas. I have yet to trial those here though so Im not sure how they would do. I would dearly love to try a Tulip Tree (Liriodendron) here in Darwin, but I dont have the space for a tree that large if it did grow in this climate.

You could be right about those tropical winter temps! There are different cultivars of M grandifolia, though, and it's possible that one of them might be better suited to your climate than the one you've got. Your best bet is to try and find a healthy one growing in your area--maybe in a botanical garden--and then try to get one like it or maybe even propagate from it if you're allowed. Alternatively, you could try growing several of them in your garden, each one in a slightly different microclimate. Could be that there's something particular about the spot in which you've planted it--rather than the general climate--that it doesn't like. The great irony is that people grow M grandfolia without problem in many parts of Australia, but struggle to grow the sub/tropical varieties that apparently grow like weeds in your climate!