I have irises from three sources, and one has done reasonably well, but two have been total flops with plants diminishing in number each year and rarely making a bloom. What are the most important requirements for them? In our previous home they could naturalize. I had gotten to taking them for granted.

Bearded Irises are pretty good at growing in a lot of different cultures, but I think they do best in a well drained soil with a neutral or slightly alkaline soil. Some irises are able to compete better in a naturalized state then others. Many of the more modern irises are more likely then not going to loose the battle with other plants. It's best to divide them as soon as you see crowded rhizomes, and a reduction in bloom. Soil testing is good to do so you can amend the soil to best meet their growing needs. Many irises like a nice chill period during the winter, others don't seem to mind a warmer winter. You just have to try a few and see how they fare. It's sometimes best to get your irises from vendors who develop them in climates similar to yours. Especially if you're in an area where you have high temps and warm winters. If you live in an area that has extremely hot, dry summers, you may want to cover the rhizomes with mulch and water periodically. I looked up where Bryan, TX is, and I'd say that you're probably in that very got summer zone. I have a friend in Phoenix and I have sent a few irises to her. She has covered the rhizomes with mulch, and provided shade cloth or partial shad for them, and they fare pretty well for her in there multiple 100 + degree weather. The irises that do best for her though are the ones from Southern California or Blyth irises from Australia. The early bloomers work best there, late bloomers just get fried.

Thanks for the response. Our summers are very hot, and our winters rarely get below 22* F, and any temp below 30* F does not last long. During six years here, I have not seen the ground freeze even once, and rarely see ice on puddles.

I think what I am going to do is take out the ones that are doing so poorly and replace them with a different type flower. I may try some foxglove, but since I have no experience with it, that could prove to be a bad choice. There are a lot of flowers that just do not do well here.

WAMcCormick ~ I have discovered that foxglove likes the cool damp climate of England, rather than the dry summers of California.

We get a decent winter here alright, with snow and ice, but the summers are hot and dry, though not as hot as other places in CA.
I am experimenting with one in mostly shade. The one in sun hasn't done all that well.

Maybe if we move to the Oregon coast, I will grow many plants that do better there including foxglove.

I grow foxglove here, but they are planted on the east side of the house.

Thanks for the comments.

I need something that gets 24" or more in height and can take Texas heat. I want something that can go "in the back" along a wall on the southeast side of the house. I prefer something that shows off most of the hot season. Any recommendations?

I have tried foxglove years ago, but they didn't grow very well. Odd thing is, after a winter flooding a couple seasons ago, some foxgloves popped up under my tall junipers (you can walk under them). I have no idea where they came from, but they grew well there. Some tomatoes popped up on the hill that year and some other volunteer plants. The deer took take of those....

Last year a volunteer pink campanula popped up in a pot by the pool. This year, a purple one popped up in the same pot. I do not grow campanula in my garden, so it must be garden gnomes hard at work.

@WAMcCormick

Have you looked into amaryllis belladonna's? (aka naked ladies) I have them planted along my fence line in the iris field. They do not want, nor require any summer water. So you just plant them and forget them. They are native to South Africa, so they'll do fine in your heat....as they do in our 100+ degree summers.

Canna lilies can take they heat, but require more water.
Liatris can take the heat and looks better behind other plants.
Red Hot Pokers
If you don't have a deer problem.....agapanthus.

Digitallis and amaryllis both do well here, and the deer like neither of them. The digitalis tends to be biennial, though. So unless you initially buy it two years in succession, expect the seedlings to bloom only every other year.

Thanks for the suggestions.

Belladonnas are a good choice in some situations, but I want something that will bloom for a majority of our long growing season.

I have some cannas, and they are beautiful, but I want something smaller and with a little more "show" than the cannas I have.

I will check the other three Sunny Side. They are new to me. Thanks.

Cannas don't do that well here, but the most "bang for the buck" is 'Tropicanna'. The foliage is really beautiful.

I grow irises in Arkansas. We get a lot of rain in the spring and heat in the summer.
I have some irises growing in a naturalized state on a rocky clay hillside. My flower beds require lots of organic matter to help improve drainage. The rhizomes often bury themselves under the soil for protection from the heat. Due to the humidity we have to monitor for rot.

Different varieties work for each gardener in the same area. I can raise varieties that other long time iris growers around here cannot. If you like irises, don't give up.

Bea do you belong to any iris clubs?

I just popped in into this thread and after some thought, I would suggest growing dahlias as they flower late, love heat and bloom until first severe frost. They go well with daylilies. The other group that might interest you are the black eyed susans. ( Rudbeckias). Dahlias come in every size and shape. Some are very tall and would need staking. Others are medium sized and even some are pigmy for the front of the border. They are very colourful so you can choose any that matches your taste. With the climate you describe, you could probably leave them in ground always. Since most dahlia growers are from cooler climates literature is very skewed towards treating them as annuals or as summer bulbs. In my original home town in Buenos Aires, with a very similar climate of yours, dahlias would go into the bed and stay there. One would only lift them in early spring after the clumps became too crowded. btw.dahlias are native from just across your border: Mexico!
I did grow foxgloves ( digitalis) there in BA, but it meant a lot of care. They seemed to resent the lack of winter chill. I did grow tall delphiniums there. Again they fare much better here. If what you are looking for are tall vertical accent, then I'll try to imagine something alternative, ( quite a few bushes could do the trick: Hibiscus, Oleander, Crepe myrtle, etc and even many of the trumpet creeper climbers)
Arturo

What about Lantana? I have family in Arizona and she has some growing in her garden, and it's almost bush like it. I really like all the different colors of flowers on the same plant as well. I bought one a couple months ago after I was advised that in our climate Lantana is a perennial rather than an annual. I potted it and she enjoys my patio which gets sun from sunrise until about 4pm, we do water in the evening when we haven't had rain for a couple days.

Have you looked at Annie's Annuals? They also sell spectacular perennials that do AWESOME in heat. (I know, because every time I look at that book, the really awesome plants require super-hot conditions). It's worth a look and a drool.

I like Lantanas too. May give them a try. Thanks.