Do you also have tall grass prairie grasses growing -- they help to hold up the plants. Are they getting enough water -- they will fall over if not watered enough.

I don't have problems with bee balm. culvers root or R triloba falling over, but have had problems with Cupplant and tall coreopsis. I use various plant support gizmos from Lee Valley Tools to hold them up. I place them early in the season so the plants grow up through them and the supports are nearly invisible.

Here is a link that might be useful: Plant Supports

Some plants get floppy if the soil is too rich- many natives prefer a lean soil.

Insufficient light is another thing that'll cause many plants to flop.

Patrick Alexander

These prairie plants all expect to be crowded together with other forbs and grasses. The grasses are very important structurally.

My "prairies" are gardens that are only four or five feet wide, and the plants on the outside always flop. How could they not? I mean, the stems are less than half an inch wide and many of the plants are six feeet tall or more. So we create a kind of framework of support rods and twine that encircles the entire garden and holds everything up.

Thanks for the info on plant supports. I use some old metal plant stands. I have 3 different heights. I use the tall one for Indigo spires and rock roses. They spill over the top and I plant shorter plants at their bases.

i think the grasses are the key. in my beds with little grass the flowers flop. in my areas that are mixed grasses and forbs - i dont have a flopping issue.

I use those plant supports on beebalm salvia etc.But on those ten foot native sunflowers I use a ten foot stake and I tie it with trash bag ties they make for plants I also use it on my swamp mallow. Sarah

For shorter plants, you can use tomato cages. just cut them as needed. Much cheaper.

One of the cheapest plant supports I've found is to buy a roll of fencing--the type with the large square mesh--and cut it to size to fit the plants. I usually get 4-foot high fencing and it works fine for the larger, floppy plants. I cut the bottom wire off so that the ends can be pushed into the soil. If you put the cages on early, the leaves will grow through the cage and it will be barely noticeable. The cages last for years, rust and all, and the roll will give you a lifetime supply.

I have an all native plants garden down a 4' wide side strip bordering my very staid and conservative neighbour's driveway. I have 10' cup plants, 12' tall sunflowers and the like and no flopping. There and no grasses. I never water. Well, OK, since we didn't get any rain from May 27 to July 18 here, I watered once on the 10th of July!

However, the soil is awful! Sandy, Sandy, Sandy and only a tiny bit of peat and compost. I think if your plants are flopping it is because the soil is too rich and they don't have to develop big roots to find enough nutrients to get big and then don't have the stability of the root system.

I didn't plant grasses as I feared that would be asking too much of my staid anc conservative neighbour. Although, I now find out he can't stand the rest either -- even if it does bloom! I feel like going and cutting all the blooms of the plants and bringing them indoors -- but then what would the hundreds of insect I have never had in my downtown garden before eat and live on, not to mention the butterflies bumblebees and solitary bees. In the two years since putting this garden in i have had dozens of butterflies, crickets, black beetles, stripped beetles, praying mantises, lady beetles (tons), and now with a one year old pond I have had Dragonflies and today I saw Dragonfly Nymphs in the water.

Thank you for your ideas, and suggestions. I think that I will try the roll of fencing for the sunflowers, because soon thay will be blooming, and down thay will come. I hope that Home Depot carries it.

No one has mentioned it but is it possible they are leaning over to get more sunlight?