There are dozens of things that will work. I've given a link below rather than trying to list them all.

One thing to think about, though, is that you want to pick each flower when it's best for drying and then dry them right away. Results will be much better than if you dry "leftovers" that have been sitting around.

For wreaths, you'll want to grow fillers/backgrounds such as lady's mantle and artemesia, and you'll need a lot for each wreath.

Here is a link that might be useful: What flowers are you growing?

Wow thanks, that's good information. Interesting that you finally had some success growing larkspur, I had crossed it off my list. Maybe I will try it.

So, when is the best time to pick flowers for drying? I don't intend to leave them sitting around, I just don't have the experience to judge how much seed will yield x amount of floral material. Is there a great reference book I can get my grubs on?

I realize now I could have been more specific, as to annuals, or perennials treated as annuals, ie physalis alkekengi, but found lots of great ideas here. As it turns out, I have lots of perennials that are on the list. I use these for winter interest in the garden, where they dry on their own, then I cut them down in spring. I will definitely experiment with drying a few dozen bunches!

neil allen and others, got any pics for inspiration?

I'm afraid the answer is that every flower is different and that you'll probably have to experiment a bit until you find something that suits you. Here's a few things we've discovered:

More often than not, it's best to pick before pollen develops -- but definitely wait until after it develops on any achillea -- otherwise, the flower will dry to a set of uninspiring pinpoints.

If you have any filipendulas, pick before the flowers really open, or when just one or two of the tiny flowers in the head have opened. The tight buds dry nicely -- open flowers shatter.

With xeranthemums, you might consider harvesting the whole plant, with some flowers in bud, others open and in color and some past their prime, basically silvery ghosts.

Centaurea macrocephala -- when you've got a fluffy ball of yellow petals with no browning on the tips. If you miss that stage, you can wait until the flowers are gone and use the "basket" that's left.

Statice -- on most colors, there will be an inner row of white bracts contrasting with the overall blue, purple, magenta, etc. color of the flower. Wait to pick until you see the white bracts. They'll disappear when the flower's dried.

Gomphrena -- you'll have to get a feel for it. Too late and the head will have begun to shatter, but too early and not only will the head be smallish, but the stem will be thinner and likelier to nod. Even in best of circumstances, gomphrena stems are more hygroscopic than just about anything else. Can also harvest the entire plant of the globosa types, especially dwarf varieties, which can be incorporated into wreaths.

Helichrysums -- many people pick when the outer bracts are still unopened, but Roberta perfers to wait on most until the flower is open and showing a yellow center.

Artemesias such as Silver King -- pick when stems are long (flowers may be forming on the ends of the longest) and leaves are in good condition. Flowers are inconsequential.

Sweet Annie -- pick when flower buds begin to form or stems are long enough to suit you.

Lady's Mantle -- pick when flowers begin to turn bright yellow. Use foliage for wreaths. Easiest way to pick is to grasp low on the stem and pull gently but firmly away from the base of the plant. The base of the stem will be brownish.

Sorry -- no pics at present

I'm saving this info., thanks neil allen for your generosity. I'll take notes of what works, and what doesn't.

As luck would have it, I only have three of the perennials on this list, but I have lots of each one! They are achillea (two or three var.), alchemilla (the lady's mantle), and artemisia (Valerie Finnis). I get that you wait until the centers show with the yarrow. I have dried yarrow just keeping it in a (dry) vase.

Did you mean the flowers (not foliage) of lady's mantle are used in wreaths? It sounds like you pick the whole spray? Do they keep on flowering, like the yarrow? I love a long bloom season.

I will take your advice and experiment.

We pick and use the entire stem with its foliage and flowers. They have one big flush of blooms in late spring/early summer then some sparse bloom along about August or September, but not enough to count on.