Does the plant annually return to your garden?  Does it perennially die each year?  Believe it or not, this gardener, at the beginning of her gardening career, did not know the difference between the two!  Beginning with a spring garden of tulips and hyacinths, I gradually learned which plants would be a welcome returnee each year, and which would have to be replenished on a yearly basis.
 
Perennial gardens are best planned ahead.  If gardening, and all of the work that comes with it is your passion, why not begin with one or two areas, planning your plantings around a theme.  For example, a cottage garden, with those plants that with one whiff return us to our childhoods, would delight with the simple elegance of hollyhocks as a background plant, especially if backed by a fence as they will reach a height of 6’.  Opt for the old-fashioned variety that looks as if they have been water-colored.  Or experiment with the double bloom hollyhocks, perhaps the majestically purpled Alcea Rosea ‘Royal Purple’.  Staking will ensure a regal carriage.  One caveat; hollyhocks are biennial, which means that they usually do not attain their full height the first year; rather, they will make lots of leaves, 10 inches or across, near ground level.  The leaves will disappear in the winter, and reappear the following spring, quickly growing tall flower spikes.

You will want to plan your garden with the tallest flowers in the back, mid-size in the middle, and border plants in the front. 

Russian sage (Perovskia) is a reliable grower and a must-have for a cottage garden.  Plant Perovskia in front of the hollyhocks, as they will attain good height; add in delphiniums and buddleia (or butterfly bush) as attractants for hummingbirds, bees and butterflies. Next in line from back to front  should be the cultivar ‘Little Spire’, a semi-dwarf, more compact Russian Sage that grows to only about two or three feet in height.  With our temperate weather lavender is a must-have in a perennial garden, and is a good offset to the similar texture and purple color of the Russian sage.
 
Bring a little “pop” into the plants in front by planting coreopsis.  As we’ve outlined a garden with a pink and purple theme, why not opt for the ‘Moonbeam’ whose pale, yellow, daisy-like flower will introduce a variant color that will blend rather than clash.  After first bloom, deadhead for a second flowering.

Platycodon grandiflorus (Balloon flower) is a special, long-growing beauty that will border your cottage garden with style and grace.  The plants form a low, neat mound, bearing 2-3 inch cuplike blossoms accented with delicate purple veins and yellow stamens.  A cottage garden standard, they also make excellent cut flowers.  All of the above listed flowers will thrive in good soil, with strong sun, and afternoon shade.

Perhaps the most immediately satisfying perennial plants are hostas.  They fill out beautifully, return year after year, and are striking in their individual markings. Use them as foundation plantings, border your trees with them, or define pathways with them.  They require little or no care, and will thrive in shady areas.

Experiment with perennials!  If a plant doesn’t work in one area, replant it in another with different sun/shade qualities.  Water, weed, mulch, and enjoy the return of your perennial gardens for years to come.