Question
My husband and I are planning to plant a perennial garden for my mother-in-law for mother's day. I'm looking for suggestions on plants that will bloom and be pretty this year. We are planning on getting plants from a local nursery. Also, do you reccomend filling in with annuals to make it look fuller this year or would that just crowd the perennials.  

Answer
Tara,
First things first. The very first thing you need is a plan.It doesn't have to be elaborate or complex,just a rough outline of the area and a note of all of the characteristics of the site.Take a photo of the site first and sit down with it to put it on paper.If you have not picked a site,consider these points:
Perennials(most) need full sun and well drained soil to get a good start. If they aren't planted in a good site with good soil preperation,your expectations will be diminished greatly.You will need to clear your site of all weeds or sod and buy big bags of good potting soil to replace the soil that you had to take out.Also some bagged peat and compost is essential for good root development.The site HAS to be weed free. If this is your first endeavor into perennial gardening I suggest a small plot,either an island bed or a border against a fence or other structure. An island be is an irregular shaped feature with various heights of perennials and of course you can use annuals on the edges or to fill in until the perennials start flourishing.
How much time can you give to this for watering the first few weeks after planting

Perennial plants will NOT be an instant picture of what you have in your mind until at least 2 years.Perennial plants very rarely will bloom the first year planted,although of course there are some exceptions.That is why annuals are essential if you want some instant color. When you look at plant catalogs and see the beautiful perennials in them,believe me that is a misleading ploy that companies have to use to sell their plants. Not to say,that they will never  look like that but they could look like that years from now.

I can give you a list of perennials that I think are the easiest to start out with and don't forget bulbs.I use hundreds of bulbs every year for continued color from spring to fall. I will also give you a list of great mail order companies to look at on the web.Also,think about unusual foliage plants that have varigated,striped or speckled foliage that is beautiful without any flowers at all. Another very important point: DON'T plant too many different varieties together in one bed.Try to repeat the same plants at least 3 of each variety in groups together,not scattered among the other plants. Taller perennials should be in the center of the bed and work your way out with medium height and lowest or edging plants on the outside edge of the bed.

Here are my favorite easy to grow perennials for zones 4 to 10.
Full sun perennials:
Black Eyed Susan,Phlox,Bee Balm,Salvia,Cone Flower,Aster(Michaelmas Daisy),Chrysanthemums,Catmint(herb),Evening Primrose,Verbena,Dianthus,Russian Sage,Veronica,Daylily,Oriental Lily,Peony,Achillea(Yarrow),Hibiscus(hardy type),Sedum(any type).

Shade perennials:
Astilbe,Anemone,Columbine,Ferns,Hosta,Lily of the Valley,Violet,Lady's Mantle,Helleborus,Tradescantia.

Spring blooming bulbs(plant in the Fall):Daffodils,Tulips,Grape Hyacinths,Scillia,Iris,Crocus

Summer blooming bulbs(plant in Spring): Gladiolus,Dahlias(not hardy in zones 4 to 7.

Good foliage perennials: Helichrysum,Coleus(not hardy in zones 4-7),Ferns,Hosta,Lamium,Snow on the Mountain,Ivy,Vinca Major,Vinca Minor,Sweet Potatoe Vine (annual),Chameleon

Here are some great perennial plant companies you can find on the Internet:Jackson & Perkins,Wayside Gardens,White Flower Farm,Dutch Gardens,Van Bourgondien & Sons,Bluestone Perennials,Van Dycks,McClure & Zimmerman,Walters Cardens,Shady Oaks Nursery.

Have Fun and Good Luck!!!!