Here are two ideas Kandi!
Place a smaller pot inside a larger pot and fill the area between the two containers with pebbles or rocks. You can also use a wider or longer planter and arrange several pots inside, filling in the space with soil, rocks or pebbles.
Arrange pots against a fence, deck rail or another structure that can help keep them upright in heavy winds. You can also arrange them next to a windbreak, such as against a solid fence or along a wall. Pots are also less likely to tip over if you place them in a corner or group them together.
Rocks, bricks, sand, anything heavy in the pot.
Hi Kandi: Like Naomie, I'd put something heavy around the inside edges of the pot, or, sand, maybe 1/4 of the way up the pot. Good luck
Fill the vase with sand. I pinch mine out of the sandpit.
Hi Kandi: I just thought of something. If you're talking about individual flowers, you can glue, or wrap the bottom of the stems to a piece of metal, like a nut or washer. Good luck