Mike, I had two 50 ft. lengths of drip hoses wound in, out and around the plants with mulch covering them - all throughout the garden in the veggie garden. The mulch was piled on 8 inches thick or thicker under and around them. I put covers over the tomatoes in late July through August. I have good well water, so no chlorine that can damage plants. Notwithstanding all that I did, when temps reached 110-120, everything just turned brown, and then blister beetles ate what was left. I had tall, dark green, beautiful corn plants with 2-3 huge ears on each plant, but upon checking them, they had few developed kernels. Total loss. I planted more than one hundred tomatoes (seven varieties), corn, beans, cantaloupe, watermelon, bell peppers, three types of hot peppers, Red bells, zucchini, and onions. Normally I get enough to can, freeze, eat fresh and sell at the Farmer's Market & Health Food stores and still have enough to donate to the Food Bank. Not last year. The only tomatoes I got were a handful from the plants I grew in large pots, but only a few. They were sure good though. Cherokee Purples were especially yummy and the Lemon Boys. I think I got about 20 tomatoes altogether. I got more than everyone else around here. Their plants kicked it in June and July. I did get some okra from the plants in the smaller, lower garden and a few pitifully small Early Girl tomatoes, and a pretty good harvest of Jalapenos in September when it cooled down a bit, but that was all. I put so much work into it and expense. But it was just too hot. It was like standing inside a furnace ever day. I lost several small trees, one large weeping willow and several Eponymous shrubs. And what the heat didn't kill, the voles did, chewing the roots off several of my roses. What a horrible year! Sorry to go on about it...

Liriope spicata and euonymus fortunei (wintercreeper) are both fast-spreading and good in full sun on slopes. They can each be invasive but not as bad as ivy.

Camellias want rich acidic soil. Our soil in VA is acidic but I still add lots of peat when planting camellias. Baltimore has similar growing conditions. The biggest problem for me, and perhaps for folks in Oklahoma, is wind. If I can protect camellias from the wind, they grow fast and are drop-dead gorgeous. Sad to say, I've lost more than I want to count after fairly short periods of cold winter wind. Might have better luck if you wrap them in burlap, and stuff straw between the tree and burlap.

I live in a colder zone than you, but this is the time that my foxgloves are self-seeding in the garden. They will sprout both now and in the spring for me. It's up in the 90's and uncomfortably near 100% humidity, so I can't imagine that your growing conditions could be much worse. Just keep them watered and shaded and they should do well. They need light to germinate, so sprinkle them on a leveled soil surface and water them, but don't cover them up. The most common type is biennial which means one year it grows just a low rosette of leaves, the second year it flowers and usually dies. So you do want to let some of them go to seed so you will have more. Delphiniums are one of a handful of plants I have intentionally grown from seed, and if I remember, I did it in pots in the spring and then planted them out. I was successful though I hadn't grown perennials from seed prior to that. However, I currently have Delphiniums that are self-seeded in my garden. They bloomed last year and then sprouted last fall a bit and mostly this spring, but I don't know whether spring is the best time for them. Here are some directions for starting them from seed. They suggest 65-75F during the day, but once they have germinated, they should be fine as long as they aren't allowed to dry out, one of the more difficult things to deal with for young plants (but they also don't want to stay soggy!) IME seed germination often has a lower range of acceptable temperatures than actually growing the plant.