Pea sticks are a good thing for staking in a garden.
See the "how to" in the link.
Linda C

Here is a link that might be useful: pea sticks

Perhaps your babying your plants too much?

They'll do best -- and will remain upright -- if grown in full sun with minimum supplemental water and no fertilizer.

You can use a tomato cage when they are very small - when you first plant them or in early spring before they start grow again. I just find them the best installed when they are young so they can grow through it. make them look much more natural. you'll probably have hard time if you try to install it now.

You might only have bamboo stake option right now. and maybe try cages next year. you don't have to stake every stem. you can also put the stake in around the plant and go around with the garden string, it may not look as good as you want it to be, but it's like first aid.

It's strange that you have problem with those plants you mentioned. i have two of them in my garden and I've never had problem with them falling. They are the most sturdiest plants in my garden. and they are all 3-4 feel tall. how bizarre. Is the garden bed fairly crowded? or do they have lots of rooms around? if latter, try to plant something tall and sturdy near by. it might help to stand up better. Also sometime if tall plants are planted next to a wall and get shade they try to come out of the shade and it kind of looks like they are flopping. They are really the best in the open space with the full sun. I don't know what your situation is but it's a guess.

By "Gaurardia", did you mean Gaura, or Gaillardia?

Gaura's not an upright grower; it sort of fans out (I suppose you could describe it as flopping). But if it's Gaillardia (Blanket Flower), those stems should be stiff and sturdy and I'd agree with Jean that perhaps you're giving them too much love.

Can you tell us more about your garden?

Yes, I meant Guara. I do think that the verbena needs to be moved out. I have a forsythia that is shading it some. The guara might be ok and just flopped more after a heavy rain or watering.

Yep, my gaura practically lies down on the ground after a rain or watering. But even at its best, it's not so much an upright plant. In fact, that's why I grow it even though it's an expensive annual up here... it's such a soft, delicate look compared with my sturdy lilies and iris and echinacea. Sort of like a fine-bladed ornamental grass, but with pink flowers!

V. bonariensis isn't hardy for me either, so I can't speak from direct experience, but it seems that staking would be the last thing you'd have to worry about with verbena. Perhaps shifting it out of the shade of the forsythia's what it needs!

If you do relocate your plant to a sunnier area, make sure it's during a cool part of the day (a drizzly rainy day is great) and keep a close eye on its water until it settles in again. Good luck!