Perhaps I'm not understanding the question, but as I see it nothing much is going to try to grow under a 3' tall deck (weeds and such need sunlight). I'd just do the general ground prep (some black plastic won't hurt) beneath the deck and then not worry about it. Skirting the deck will cut off more light to errant weeds and would look good, grounding the deck to the house.

Just a few random thoughts ....

Unless your Terminix guy is OK with crawling under your deck, don't put any wood product under there.
What direction does the deck face and how deep is it from the edge to your foundation?
I would hit it with brush killer, the stuff that lasts and then check with the 'deck' forum for recommendations.
Do you plan to lattice from the deck to the ground to keep the cats/possums/skunks/raccoons out from under it?
Below my deck at the other house is just plain dirt graded to make rain drips flow away from the foundation but the edges are latticed.
Any flower/shrub border you have up to the lattice, you'll have to be vigilent to keep tree seeds from gaining a foothold. They like to start in those spots for the moist soil with no other tree root competition..then hard to get out. We used the cedar colored vinyl/plastic lattice.

What I did last time we redid the deck was to put 2-3 rows of boards parallel running along the house wall and attach the boards with galvanized screws. That way, should there be a termite issue or a water rot issue you can access the areas for termite treatment/sill replacement without having to take up your entire deck flooring.

I don't have any experience with it, but what about the rubber mulch made from recycled tires? I think it comes in colors, too. My only thought about the plastic is that you might not want anything that water can gather in and turn your nice new deck into a mosquito heaven! :-\

Thanks folks for the ideas!! Zigzag, you have captured one of my thoughts there, how likely is stuff to grow under it? Around where I am, I've got weeds the size of trees and bugs the size of airplanes. And thanks to all of you for the lattice thought, I hadn't even thougt of that yet. My current decks are the smallest allowed by the county to meet code. I knew I wanted a large one, and we decided to do that ourselves after building to save the contractor dollars. So current ones are really junk. Claudia, does the rubber mulch hold water? If so that wouldnt' work but if not, sounds like a good solution. I don't have much growth now where this is going in but want to eliminate it and keep it gone. I know from using it elsewhere, the landscape fabric will allow water to pass thru. The new deck is going to be a 28 X 16 so no mowing or weed eating can be done toward the center. Perhaps a good weed killer would be enough to keep them gone, combined with the lattice. Dottie, great idea about the 2 or 3 rows of boards next to the house. I'm going to pass that one on to DH. Sorry for the rambling, but thanks so much for your ideas!!

The concern that Claudia mentioned about plastic and rainwater puddles is extremely valid. Those tiger mosquitoes don't even need a puddle for their larvae to develop. According to what I read, they can crawl between moist leaves and leave their eggs which develop in just that amount of moisture. And the tigers bite as soon as they land on you.
With shredded tires, you may be adding something unnatural to the soil that could contaminate your borders around the deck base. And..in the summer..doesn't shredded rubber give off an odor?

If you decide to lattice from the deck floor to the ground no one will see what's under there. Just be sure to properly grade the ground under the deck away from your foundation. Put your lattice on with screws and create a short section which can be easily removed..maybe some sort of hook and eye attachment so your termite guy can get under there to inspect annually.

Some great ideas here - your deck is going to be spectacular and is about the same size as one I added to a corner unit townhome a long while back.

Here's another suggestion ....... I had my railing built lower than normal height and built on a wider than normal top board - this provided oodles of additional 'people perching' space when I had a bunch over, and the wide top board securely supported planter boxes w/out needing any attachment hardware. (If you want to consider this, be sure to check your local building code regs - some areas dictate a certain height railing determined by the deck height off the ground - mine was but a foot or so, thus the lower rail was fine.)

Yes, there are some excellent ideas here!! Thanks to all of you so much for your thoughts!! I've already been thinking about how to incorporate some planters zigzag! I'll have to explore that idea. I can't wait till we get this done!! I've been waiting now for 2 and a half years, and I'm excited about being able to enjoy the land and views on a nice afternoon!!