In my previous post, I mentioned seeking advice from GardenWeb members about making the backyard flowerbed better next year. The design forum turned out to be the landscape design forum, and most people there are interested in major redesigns, when I was just looking for some flower and plant arranging ideas. They suggested moving the boulders and all kinds of silly stuff. So, I posted it in the annuals forum and got some better feedback. Here are some of the ideas, along with some from a few of the landscape design folks:

• Don’t move the lavender; large established plants do best left in place. I have not found it to transplant well even moving it when not in bloom, cutting it back and ensuring I took a huge amount of dirt beyond the roots. (However, I’m sure it has been moved successfully by others.) I’d recommend working everything else in your decided upon color scheme around the existing lavender. If you want bigger drifts, add additional lavenders. And repetition would tie it all together. Lavenders, blues, greys, and the right shades of pink go well punctuated with white. A less jarring yellow like the pure lemon yellow old fashioned Hyperion daylily works in that color mix too, used sparingly.
• Choose 2 to 6 kinds [of annuals], (depending on the measurements of your beds) and plan to put them along the front of your perennials in drifts of no fewer than five plants, but different numbers of each kind. (5 plants, then 9, 7, 11, etc.) As you evaluate them, choose some that have a “spiky” form (like Victoria Salvia, for instance), some that make low mounds (profusion zinnias, maybe), some that make daisy shaped flowers (rudbeckias would do), some that make trumpets (nicotiana would be one), etc. In other words, think about different shapes and sizes, as well as colors. If you still have trouble narrowing down the selection, look at the foliage. Any plant that has good looking leaves throughout the season, in addition to nice form, texture, and color, is THE one to go with. As far as your row of perennials go, you might want to rearrange them a little so that you don’t have a polka dotted look. Group your blues together. Group your whites together, etc. But then, don’t be afraid to repeat colors down through the border either. Just make the “dots” bigger.
• Like you idea of keeping coneflowers, lavender and Shasta daisies. The white daisies will make the other colors pop. Some annuals which might fit: Celosia Fresh Look (red one), Dianthus Amazon Neon, Pentas, Statice, and Vinca. There are a few of the less rambuctious zinnias which would fit this space. They also have a range of heights which could be used to your advantage.
• Consider low roses, like Knock Out Blushing rose.
• Zinnia Profusion, Pink and white tones: These are fabulous for the front of a border. They bloom non-stop, and probably will do better for you than they do for me. Our intense sun causes the pink shades to fade. Mexican Zinnia (Zinnia angustifolia) in Crystal White is a truly outstanding plant for us. It will be at its very best in late summer when everything else is pooping out. Salvia farinacea, Victoria is my very favorite blue and it’s spiky too. It’s about eighteen inches high. Delphiniums or larkspur would probably do well for you, and again, they provide spiky form that is so valuable. If they bloom all summer in your mild climate, I’d definitely include them. The larkspur will reseed. They are tall, but the foliage isn’t, so they don’t seem so tall, if you know what I mean. Sweet Alyssum will bloom all summer (for you, not me), comes in whites, lavenders, and pinks. It’s great at the front of a border and provides nice fine texture. It will also reseed if happy. Helichrysum is a splendid foliage plant that would provide silvery blue color with its fuzzy leaves all summer. Lambs Ears would do the same and provide some bolder forms. You could also consider stachys grandiflora. It’s blooms are rose pink. Very attractive plant and if you have good luck with lavender, you should do well with it. Alternanthera is another wonderful low growing spreader. It has purple/silver/green leaves that are metallic looking, but not garish. It weaves through other plants well. It will spread 3 feet by summer’s end, so set it back in the border, to avoid having it all over your grass. I second the motion for pentas. They are splendid annuals that look great the whole season with absolutely no care. red, pink, rose, lavender, and white. I personally like the full sized ones (about 18 inches) better than the dwarfs. The blooms are in scale better with the larger plant size. The whole plant is neat and elegant. Blue Lobelia, crystal palace is a great front of the border mounder that provides fine texture and really really blue flowers. (I’m so jealous to think of all these lovely plants you can have all summer that I can only have in late fall and early spring! Pansies! Snapdragons. Heliotrope. Vincas are hard to beat in the heat of summer. They come in a wide range of pinks, reds, whites, and even lavenders. They have beautiful dark glossy foliage, make neat mounds, and never say die till frost. They reseed. Wave petunias. Some begonias and dahlias would fill the bill too. Celosia, gomphrena, Amaranthus, nicotiana and statice would all be possibilities too. Oh, and browallia (blue).
• As you vary the number of plants you use, also stagger them in your bed. In other words, for a drift of seven, say, plant 3 across the very front of the bed, then plant 4 more right behind them. Then begin the next drift of plants in that odd space in front, so that the flowers blend together and don’t seem to be rowed up. Make some of your drifts go deeper back into the bed, and other drifts spread out wider. (I hope this makes sense! It’s easy to do, hard to explain!)
• I believe there are three ways to look at the important element of repetition, especially when working with annuals. You can repeat the same plants down the line, you can repeat patterns of plants down the line, or you can repeat colors. I am an avowed plant nut. If it grows, I want it. This can make repetition more difficult because of space limitations for all the varieties I want. So, I have learned to repeat color masses. In other words, I might repeat red by a drift of pentas, and then petunias, and then dahlias. All red, but I get to feed my plant habit. See? It works rather well, I think, and also allows you to repeat colors from deep in the border to the front, and then to the middle, which, I think makes for an an interesting sight line. (Note on reds: use blue/reds, or orange based reds, but not both. With your color scheme, I’d advise you go with blue reds.)
• Another note about pink. It’s a complicated color to work with in mixed borders. There are the lavender blue based pinks and there are the yellow based pinks and there are the coral (orange based) pinks. They’re all pink, but they may not always play well together. You can either stick to one shade, which may mean one kind of plant, OR you may want to give them a good bit of separation in your border and make sure they play nicely with their neighbors. I did a pink border last year, and then dug it all up this year and started again, so this advise is from recent experience. To be safe, choose all your pinks on the same day and hold those plants next to each other and see if they sing or squabble with each other.
• One other annual that I HIGHLY recommend is the new Euphorbia, Diamond Frost. What a huge stunner it is! It’s about 18 inches high and wide, making a perfect mound of what looks like a solid mass of snowflakes. It bloomed all summer here right through the three weeks of 100 Plus temps without ever looking wilted, dried out or brown.
• In my own gardening I’m really moving away from the primary use of perennials to using perennials as accents for a framework of more substantial, more year-round plants with a more diverse range of attributes – evergreen foliage, winter buds on deciduous branches, fall foliage, etc. I have a sense here that you’re looking not just for unity and repetition, but for structure and durability as well – which you might achieve by moving your model from a flower border to a mixed border. If I were you I’d go to the nursery and look somewhere other than at the tables of perennials. Check out the ground covers including the shrubs such as junipers or Salix yezo-alpina, the dwarf conifers, the little mounding rhodos, the grasses, the hostas (there are lots for sun) or something other than “flowers.” And on the perennial tables, look for the plants with bolder foliage and not just at blooms. Irises, maybe? Ligularia Britt Marie Crawford, if you have enough moisture? Once you get a diverse range of plant types, you can get your unity and repetition by echoing elements, rather than repeating them – for example, using maybe three different grasses somewhere along the bed (though not at mathematical intervals!).