I'd like to ask what is a proper way to fill in planters with the annuals I've just purchased. Any advice would be greatly appreciated.

My first annuals.. 2 trays of petunias & 2 trays of vincas. Each tray has 36 plants (or 12 pots of 3 plants).

I also bought three of these planters (18" wide) to fill in.

How do I arrange them? Should I plant petunias and Vincas in separate planters? Or should I mix them? Or should I make a Vinca circle border and then petunias in the middle? Or the other way around? I guess I don't really know the mature heights of these flowers. Most of the petunia hanging baskets in a nursery suggested that petunias can be drapery..than upright. Is this a correct assumption? Is there any way not to make them hanging too much outside the planters?
Thanks in advance!

I don't grow annual vinca, but I know that certain varieties of that are compact, and other varieties spread. If you have the variety names of your plants, it would be wise, I think, to look up their growth habits before deciding how to plant them.

if so.. dampen some media ....

the fill pot with good potting media.. NOT DIRT ... and

insert plants.. roots down and water

do each bowl in a different manner.. and go from there ..

you seem to think there are rules for it all ... there arent ...

what i dont get.. is why you got two types of trailing plants ...

you might want to get a vertical plant for the center of each ...

good luck ..

ken

ps: if you dont want the plants to go too far outside the bowl ... then cut them off ...

"trailing plants"..yes that is the term. What kind of vertical plants would work here? I saw one called Zinnia, and it was vertical, but I didn't buy (too expensive.) Guess I should have.

I'll drill drain holes.

Does this mean I plant one plant and then leave 10" and then plant another plant?

I only need about 5 plants to fill one 18" planter?

This is just personal taste, but if I had both vinca and petunia plants, I'd plant them separately.

I searched Cooler and Titan, and they both have the plant habit of being "Mounded, Upright". I also found that I don't have to water Vincas everyday.

I've decided to plant only Vincas on those planters and will find another place for the petunias. The label just says "Petunia" and nothing more..

Thanks for your help!

What do you do with the rest?
Is there anyway you can create some tiny mini beds? say 1 ft by 1 ft.
I always end up with too many plants since I grow from seed. But I stick one (or more) here and there. Different locations in my yard produce different results. Go ahead a crowd them in the ground; it's better than pitching them in the trash.
Problem is ground soil. If it is not good, the plants will survive, potentially, but not do their best. Plus all the work that comes with it, like daily watering.
If you do venture into mini garden spots, mix fertilizer into the soil first, say a tablespoon per hole and mix well before planting. One week after transplanting thoroughly drench with a water soluble fertilizer.
Last resort, call your local senior center and ask if you could give away your extra plants. Drop them off. They will be gone quickly. Bring them in plastic bags so not to leave dirt all over. Never bring a valuable tray or pot that you "will pick up later".
Good Luck,
Bob

As ken said, be sure you are planting in a good quality potting mix. The bag should say MIX, not soil. Fill your pot with soil leaving about an inch of empty pot space at the top so you'll have room to water.

Potting mixes usually have enough fertilizer in them to get your plants going, but it's a very good idea to add some more in the form of slow release fertilizer. Osmocote is the well known brand, but lots of stores like Walmart sell slow release fertilizers under off brands that are just fine. Sprinkle the recommended amount over the soil and then mix it in before you start planting. (Mix it just like when you are cooking. Use a trowel or your hands.)

Then, in your pot, put three vinca (plant whichever variety says it will be the highest in height) in the center in a triangle, about 3 to 4 inches apart. Then plant the petunias around the edge of the pot, about 4 inches apart from each other and from the vincas. When you are finished planting, give them a good watering and put them somewhere that they get at least half a day of sun. All day is beter.

To keep your pots looking their best, give them some liquid fertilizer every two weeks in addition to the slow release. Some kinds, but not all, would be Miracle Gro, Schultz, or the off brand copycats of Miracle Gro, etc.

As to your leftovers, you could plant them in your yard, or just take them back to the store for a refund.

They'll be all in a spot with morning shade & afternoon full sun. I'll plant leftovers on my front mulch bed between boxwoods. Should I put the mulches back afterward or leave the potting/planting soil bare?

I also bought more planters but they are 16" deep. I read here that I can fill it up with plastic bottles or soda cans so that I can still lift it.

You can use the soda can trick to decrease the volume of soil in the pot, AS LONG AS the plants you are putting inside don't need that deep of a root run. The flowers will be fine with 8 to 10 inches of soil. If you are planting tomatoes, say, you should fill it full of soil (and even that would be adeqaute for a patio sized tomato only).