This website: http://www.dahlias.com/index.asp?PageAction=Custom&ID=2

Says- "DO NOT WATER TUBERS AFTER PLANTING!!"

while this one:
http://www.thegardenhelper.com/dahlia.html

Says- "Cover the tuber with about two inches of your soil mixture and water thoroughly."

Which is it? I appreciate the input...thanks!

Tubers have most of what a plant needs stored inside them. This is, of course, assuming all you want is more tubers...or all the plants want to do is survive.

When there's less sun (e.g. less than 14 hours a day) but there is moisture and some warmth (e.g. more than 40-50 degrees) tubers make sprouts. They eye up, create sprouts, and make foilage.

When there's 14 hours a day of light (or thereabouts) and its dry, they make roots.

When they've had both, and light gets less (or erratic) and/or water gets more, they build tubers.

If you've just planted tubers, you want roots and foilage, this will establish the plant well to grow throughout the season. You know your daylight, and your rainfall, so it really comes down to you figuring out what the small plants need most.

Advice about water, IMO, is typically suited more towards the more northern regions. If I give a tuber too much water (I'm zone 5) I have no natural daylight and warmth to make excess water evaporate. The result is that some tubers might get water-logged and rot. Of course soil comes into play, and its natural (or artificial if you've cultivated your garden) drainage.

Where you are this may never come into play.

Bottom line, you never want your tubers to be "wet" on a meter for very long. "Moist" is fine, but pushing it. Works well for the first week or so, but beyond that could inhibit root growth.

"Dry" but warm and long-lighted days are supposed to make roots develop. That's what you want before the "dry season" you may have...so the roots are far enough out from the tubers to find enough water to keep things growing.

Of course if everything is being artificially managed, then you just need to decide what you're looking for out of your tubers.

I use a meter, and watch to make sure I don't make the soil around the tubers too wet.

You're not far off where they were born, so unless you're artificially augmenting what they'd get naturally, I can't imagine you could do much to harm them.

Good luck.

Cheers,
Russ