It doesn't matter if a plant is drought tolerant or not, if you plant in a hanging basket you have to water, especially if it's in the sun.

Any basket or small planter only has so much soil and so much room for the roots to grow in. In the ground the roots can go deeper in search of water, not so in a planter.

There are some things you can do to help though...
First--use a soil that is formulated for hanging baskets. It is created to hold more moisture and when you water make sure the soil is completely wet and not just wet on top.
You can put your basket in a place that is shaded in the hottest part of the day.
There are polimers you can buy that hold moisture. When mixed in the soil they fill with water that gradually releases into the soil.
You can cover the exposed soil on top of the pot with spagnum moss to stop evaporation.

No matter what you do though it will require watering a few times a week. If you are not prepared to do this, then grow your flowers in the ground

Thanks for the tips! That helps a lot! :)

I'm thinking of automating the watering using 1/2" pvc pipes. Hopefully my wife will like the idea.

Thanks again!

Btw, while I was waiting for an answer to this thread of mine, I did some research. I found some hanging basket that used nasturtiums. I have tons of nasturtium seeds that I harvested last year. I have to find another annual that will compliment its lush green leaves and bright red flowers. I think, maroon foliage plant will work perfectly with it and maybe a touch of yellow flower from Safari Primrose. Oh, and another purple foliage of sweet potato vine.

So here is my plan. My hanging basket is circle. On both ends or across each other will be nasturtiums. Then in front, it will be the sweet potato vine. And for the middle, I might buy another cordeline or purple fountain grass. Then somewhere will be the safari primrose. Hopefully it will come out nice! I'll keep you posted.

How big is this basket? It must be huge. That is a bunch of plants for a regular sized hanging basket. I put sweet potato vine in an 18" planter one year and kept cutting hunks off of it because it was taking over and crowding out my other plants

Yeah, I noticed my sweet potato vine last year didn't grow well because my basket wasn't big/deep. I'm still going to use it or maybe I should tell my wife that the basket isn't deep enough.

I recommend that if you want the nasturtiums, you dedicate that basket to only nasturtiums. I've grown them in potting soil re-used from the year before, no food, and they looked great. Planted in the ground, with lots of water and rich soil, I got mostly lush leaves and very few flowers. If you mix them in a basket with other plants, you will have a tough time keeping all of them happy. Either the nasties will be overfed and all leaf, or the other plants will be underfed and cranky. You may be able to balance it out, but I'd rather spend time lounging and admiring than fussing over everything.

I keep it simple and fill the basket with potting soil, then poke in several seeds of a climbing nasturtium. The "climbers" are really more like "trailers." I've never had them so much as twine around the basket wires, but they trail gracefully and eventually get quite long. You could get the touch of yellow you are looking for by adding a yellow nasturtium to the red. The climbing/trailing variety I keep coming back to is "Moonlight." It's soft primrose yellow, and looks much more delicate than it is.