Actually the southernmost native range of Longleaf Pine is in northwest Lee County, which extends down to USDA zone10a and they could probably easily grow in Broward Co (10a/10b) Longleaf Pine should be planted much more than other pines because before European settlement the longleaf pine forest dominated as much as 90 million acres stretching from Virginia south to Florida and west to eastern Texas. Its range was defined by the frequent widespread fires that occurred throughout the southeast. This rich ecosystem has now been regulated to less than 5% of its presettlement range or about 3 million acres. Its range has decreased a lot over time. And their conservation status is now in the Threatened range (Vulnerable). They are much more resistant to pest and diseases than many other native pines which in turn they reach their full size at age 150 years old and they can live up to 300 or 400 years. The Longleaf Pine also has the largest cones of any eastern U.S. Pine, which can be up to 10 inches long and some reach about the size of a football. The needles of young trees can reach up to 18 inches long which are the longest needles of any pine tree in the world. They grow slow for about 3 to 8 years while in the "grass stage" in this stage, longleaf pine seedlings resemble a clump of grassÂand hence the name. But after that they shoot up like a rocket and can equally reach or exceed the growth of a loblolly pine during the "rocket stage". Here is a link that might be useful: The Longleaf Alliance

Hi Robyn. Could I suggest that an important consideration is to plant species which have the best chances of survival. For this reason, I'd be very much inclined to go for local species which, naturally, have evolved with the local soil & climatic conditions. To get an idea of which species are local you could visit your nearest patch of relatively undisturbed bushland & take notes. Take along someone with plant identification skills if you don't have these skills yourself. You might also want to talk with the environment office at the Toowoomba Regional Council about the local species which would meet your criteria & might be best suited for your property, especially for the boggy area. I note that Forest Red Gum Eucalyptus tereticornis seems to be local to you. Did you plant that one or is it a remnant of the forest which once covered your property? This species would seem to be one that would be suitable for you as it is fast growing. Silky Oak Grevillea robusta is now rather rare in its natural range which is close to Toowoomba. They naturally grow along creek lines so might grow fastest in your seasonally boggy parts. But they do well in dry conditions. I have a couple of healthy but slow growing ones where I live with an average rainfall of only 475 mm. I believe they're used as a street tree in Alice Springs & there are several very tall specimens in Murray Bridge SA with an average rainfall of about 400mm. Are yours in boggy or dry parts? Or both?

Fruitless mulberry is listed non-toxic for horses - can be a great fast growing broad canopy shade tree. Biggest disadvantages are that can require quite a bit of pruning due to vigorous growth and the male flowers produce a lot of pollen in the spring; not so good in a small yard, but maybe not so bad for a riding arena. We had one in northern California, so will probably grow well in your area. They generally stay healthy 40 to 60 years in north Texas. Oh... also, they seem to be able to handle our Texas zone 8 100+ °F stretches without supplemental water once established, though will start to drop some leaves where not catching any lawn irrigation.

Answer to flooding is to install drain lines - as long as you have somewhere to drain the water into. As far as shade is concerned you will be waiting many years to get much from a newly planted tree. How long are you willing to wait? And wet during rainy weather in combination with no supplemental watering during hot spells - if that is what you are indicating - can be a quite limiting combination. Plus most kinds of trees generate some kind of fruit, even if not edible. What part of USDA 10 are you in? It might work best to look around there for similar situations, see what is growing in them. Parks, botanical gardens, places with large trees planted in lawns.