I grow Lobelia tupa in zone 9b/Sunset 16 and it is in neutral soil, amended with compost and mulched. Watered by drip irrigation twice a week, and it's lush and healthy so I don't know that it wants wet feet (other Lobelias do). Spectacular plant, about 7' tall when in bloom;hummers love it. Dies to ground at first frost but in 10b that should not be a problem. The leaves are large, soft lime green and pubescent - lovely even when not in bloom.

My experience with Lobelia tupa is that it does fine under normal garden conditions like the previous poster mentioned. I think some protection from mid-afternoon sun is indicated as the leaves on mine tend to get sunburn by late summer.
Dierama's have been tricky for me, I have lost them in various parts of the yard, but have others which are 'happy' so far. They come from the summer rainfall region of SA (dryer in winter) and grow in grasslands, So good drainage is essential in winter as is regular irrigation in summer.

My lesson with Dierama has been you stand a much better chance in the soil than in a pot. They dislike pots intensely and slow the growth to a crawl. Hot weather makes them suffer and if a heat waves comes along, a cardboard box that provides shade makes all the difference. If the soil is moist in winter and more rain is on the way, a tarp to keep excess water off is good. Make sure they are not in soil that will get soggy. I've had good luck so far in morning sun but being nearer the coast would be even more to these plants liking. The other tip I heard was collect the seed and sow it right away to grow more plants in case your mother plant dies out. The fresh seed is easy to sprout but older saved seed is very hard to grow.

I tried my hand at Dierama last year. I had 2 in the ground and 1 in a large clay container. The ones in the ground died from what I'm guessing is too much water. The potted one is growing vigorously and spreading in size this year.

For dierama, the leaves start to get brown in the winter. You trim them off in the early spring once new leaf growth is put forth.

I wish more nurseries carried this gorgeous plant.

I also wish they did....I'd like to get a variety of dieramas without having to mail order them.....