Yellow is one of the most useful colors in the garden, mixing well with most other colors. Pale yellow suits the cool pinks and rose shades. A golden-yellow tone complements peach, orange and red. Sunshine yellow can be used everywhere. With the Pacific Northwest's mild winters and cool summer, you can have color through fall into November if you cut back the plants after the first flush of bloom.
Flowers to Seed Outdoors
If you want the maximum number of blossoms for the time and money you spend, plant Calendulas, also known as Pot Marigolds, Nasturtiums and California Poppies. These can be sown in late winter or early spring, January, February or March, and the rain will take care of watering them until they sprout.
All three come in shades from pale yellow through gold to orange, so search out varieties of a single color if you want a display of a single hue. Both Calendulas and Nasturtiums have large seeds and are very easy to sow. California Poppies have smaller seeds, but sprout prolifically from a scattering over the ground.
Flowers to Start Indoors
Some plants are easy to sow, but need more warmth to get going. A sunny windowsill should be sufficient to start cosmos, sunflowers and zinnias.
Cosmos are often pink or white, but can be found in clear yellow shades, too. Sunflowers, of course, have tall stems with cheerful yellow daisy-like flowers, but newer varieties with shorter stems and smaller flowers more appropriate for cutting are also available.
Zinnias often mildew in rainy weather but newer varieties are disease resistant and if you have a warm, sandy corner they will flower for months.
Flowers to Buy as Starts
Some plants are too much trouble to start indoors for most home gardeners, but nurseries are filled to the brim with starts to tempt any gardener in spring.
One of the first to look for is the Monkeyflower, Mimulus, with its open-faced flowers splotched with darker shades. It does well in moist, even wet, soil and like cool, shady conditions. Snapdragons also can be planted early, and are available in both dwarf and tall varieties.
Wait until the ground warms up a bit to plant Petunias, usually pink or purple but recently available in yellow. Marigolds, standards for yellow and gold color, also prefer warm soil but be sure to protect them against slugs.
Perennials Often Grown as Annuals
Pansies will often live over for another year's bloom, or even seed themselves around your garden, if you're lucky, but are usually thrown out at the end of the season.
Other perennials often grown as annuals include Tuberous Begonias for shade,
Dahlias, and the cheerful yellow variety of Marguerite Daisy