Yes, I think you need a third type of plant, maybe even a random scattering of a fourth or fifth to eliminate the regimentation and the dot plant look.
My thoughts are based on living in a colder zone where such arrangements don't have the luxury of time for really filling in and becoming the mass of color, I suspect, you are hoping to achieve.

It might be more pleasing to add a dozen or so of something like alyssum "Snow Crystals" along the outer perimeter - has a larger flower and seems to retain its mounding habit and would marry the bed to the grass edge so you wouldn't be distracted by the regimentation of the floral ring, the red mulch, the grass edge... I love pansies, but even here they get leggy and sprawly by mid summer so I rely on the Johnny Jump-Ups that spring up everywhere. Petunias might work if you can find some of the more mounding types. Portulaca (moss rose) is charming. There must be an endless array of annual material available in your area that would fit in to your color scheme.

I have a rectangular planting area built into a retaining wall at the back of my patio - and last year's Harlequin Dahlias, short lisianthus, Portulaca, alyssum, Dianthus Chinensis, white petunias, and some left over geraniums put on a good show all season. And, truth be told, it was the alyssum that tied it all together.

Evie,

If I were going for a "formal" look, I would use just the red salvias, and add a lot more of them in the outer circle. I would put the marigolds somewhere else, possibly in the back yard. For "informal", there are a lot of good options, including those suggested by duluthinbloomz.

MM

Wow! Marigolds and red salvia in January! I'd advise you to ask around your area to be sure it really is warm enough. Here, we don't usually plant these until the soil has warmed some, which means night lows in the mid fifties fairly reliably. Then again, maybe your soil never really gets cold. Anyway, the alyssum idea is a good one, but it will probably burn up in the heat by the time your marigolds and salvias really get going well. Alyssum lasts just about as long as pansies, which means as soon as the daytime highs start hitting into the eighties, their days are numbered. Petunias will last a little longer, but they usually shut down here by mid June. That probably means at least a month earlier for you. Portulaca is a good choice. I've never known it to get so hot that it won't keep blooming. However, the blooms close up in the heat of the day, so they're only really pretty until about mid morning.

I'd suggest you look at Salvia farinacea, Victoria. It has blue spiky blooms that bloom nonstop from spring to hard frost here. It would likely be perennial for you. Blue, red, and yellow makes a stunning bed. Up north, it would probably be almost too bright, but our strong sunlight will tone it down just enough. I'd put a ring of the blue Salvia behind the marigolds and red salvia. It will get about eighteen inches tall. Then, group your reds and yellows together in groups of 3, then 5, then 3, then 5, etc. of a kind, in front of that. That way, you will have bigger "dots" of color. Use a ruler and measure the distance between your plants. If you're putting them into good soil and they will have adequate water and fertilizer, you will get a nice full look if you plant them the smallest distance specified on the plant tags. In other words, if it says to plant them six to eight inches apart, plant them six inches apart. All the plants will do much better if they aren't over crowded. If you get all that in and still want something in front of the reds and yellows, I'd recommend dusty miller. The silver foliage will really set your primary colors off and will give some more foliage interest. Good luck!

{{gwi:907}}

Wanted to show you what I ended up doing. Thanks for your posts and help.

That looks very nice. I think you will like the softness of the white in front. While I like bright bold colours, the addition of the white has made it feel bright and cheery but with a calm pleasant feel.
gg

Thank you:) I used Mills Magic for fertilizer and 80 lbs of soil when planting them. They got watered at least 1/2 dozen times that day:)

I just hope the viola doesn't die back too early fro mthe heat.

It looks great evie1955! Nice choice and maybe the palm(?) will help the violas with a bit of shade.

It's hard to imagine setting out tender plants right now. We have a high of 14F predicted for tomorrow and a low of 0 F on Wednesday! Your photo reminds me that spring is comming before toooo long.

This thread was great.

Someone posts a garden proposal photo.

Others respond with a few suggestions and...VOILA!

A finished garden picture appears.

Now that's real garden talk.

80 lbs. of soil...guess it wasn't just talk!

Congrats on a pretty front garden.

Thank you Newbie:)

In a month or so, I'll post another pic:)

What are those white flowers?

Those are white violas.

Here you go, #3220

Here is a link that might be useful: White Violsa

The addition of the white looks great!

Here's a pic I took today:) Thought you'd like to see how they've grown. Need to clean them up, cut around some more, add more fertilizer but they are doing well:)

{{gwi:908}}

Very nice, looks like they are doing nicely!

Karen

Very very nice. I really like the way you planted the red salvia. I have always tried to plant in 'odd numbers.' Looks more natural and with the salvia blooms being taller and spiker, the color splash is bigger when they are together.

Just to let you know, They won't be annuals. I live in zone 9b/10a and all of those you have are perennials for me. The violas (pansy) usually die in our summers because we normally stay above 100F for week on end, so depending on how hot your summers are, the pansys may or may not be annuals. You seem to live in a warmer zone than me because i can't grow a phoenix roebelinii palm out in the open like that. I grow mine near a wall to prevent frost damage. you can count on the marigolds to reseed year after year. I planted about 24 marigolds a couple of years ago, and i have not had to buy more since. They are year-round bloomers but i usually rip them out in January when they look old and messy. Then in March, i get TONS of seedlings coming up everywhere.