Answer: Partial shade can mean many things. If it is sunny in the morning and shady all afternoon or if it is dappled light all day, then you could try plants such as columbine, hosta, perennial geranium, pulmonaria, and astilbe as well as impatiens, caladium, fibrous rooted bedding begonia, lobelia, and coleus.
If it is shady in the morning but sunny in the afternoon or during the hours around noon, it would be considered a hot sun location. Then you could try purple cone flower, sedum, black eyed Susan, ornamental grasses, achillea, daylilies, liatris and butterfly bush. Annuals would include sunlovers such as marigold, zinnia, salvia, cosmos, dianthus, and petunias.
In terms of planting now, most perennials would be sent as plants at the correct time for planting later this spring. You would start annuals from seed at different times, counting back from your average frost date to determine when. Most seed packets tell you how far in advance to start the seeds indoors. (Most gardeners find they need to use supplemental lighting to produce good quality transplants.) Many plants can also be started from seeds planted in the garden.
Since you are new to gardening you might want to look at a book or two about it before spring. I suggest the Dummies series, in particular the books on annuals and perennials. They are straightforward and explain the mysteries of site evaluation, help with plant selection and explain soil preparation which is the basis for a successful garden. Have fun with your new garden!
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