Thank you for the photo -- it is helpful -- but we need more information before we can offer ideas:

• Do deer browse in the yard regularly?
• How much summer sun does this area receive once all nearby trees have leafed-out? We see the Norway Maple nearby, but it's hard to tell how much its canopy and the house wall shade that planting area.
• Does the soil drain well, skew dry (especially given the competing tree roots), or tend to stay wet after heavy rain?
• What plant traits are you looking for?
  • mature size limits
  • evergreen or deciduous
  • a certain flowering season or foliage color
  • do you prefer to use native plants?
  • do you want any of the added plants to attract wildlife (butterflies, birds, etc.)?
  • do you have a preference for a particular plant type -- annuals (live for one year, generally with a long bloom time), perennials (live for many years, usually with a more limited bloom season), or shrubs?

Are you looking for plant recommendations to fill in areas of this existing bed (that is, you won't be removing any of the current plants), or are you asking for recommendations for any part of this bed (including the removal/replacement of existing plants)? For example, the red-purple shrubs appear to be Japanese Barberry, which is an invasive species we encourage gardeners to replace.

Miri

Deer browsing will narrow your options, and unfortunately they do eat Hydrangea and love to eat Hosta. Unless you wanted to fence the yard or protect individual plants with either regular repellent sprays or netting (which can risk entangling birds or other animals), you may want to reconsider including those particular plants since they could be eaten. While nothing is 100% deer-proof, there are several plants that are rarely eaten, and we've never seen boxwood damaged by deer. Sometimes boxwoods are confused with Japanese Holly, and that shrub is more palatable to deer, although not a favorite. Euonymus is also sometimes confused with boxwood, and deer readily eat Euonymus.

Magnolias are trees, and the smallest selections tend to mature in the range of 10-20 feet tall, so they need plenty of room. They also require full sun (6-8 or more hours of direct sun in summer) to thrive and flower well, although some (like our native Sweetbay Magnolia) can handle a bit of shade. The light and root competition from the nearby Norway Maple may stifle the growth of some plants in that area, as maple roots (and Magnolia roots) tend to be more shallow than those of other trees.

Lavender requires excellent soil drainage and full sun; peonies also need full sun to grow and bloom well. Peonies tend to get the size of a small shrub, so they'll need room to mature and not block the view of any perennials behind them (if that's how you wanted to position them).

Your candidate plant list for semi-shade and deer could still be reasonably long, so it may be simplest to see what area garden centers have available. Boxwoods do well in a mix of sun and shade (and they have comparatively shallow roots), though if you are adding any new boxwood shrubs, make sure they're a variety resistant to some of the common boxwood problems like the insect Boxwood Leafminer and the diseases Boxwood Blight and Volutella Blight. You might not find a variety with high resistance to all three, but we can say that we see leafminer and Volutella damage quite regularly. Several boxwood varieties new to the market in the past decade have improved Boxwood Blight resistance.

We don't have much information on which plants produce the best cut flowers (in terms of vase life), but overall, your plant options for the side yard (as you have even more options for sun) can include:

Shrubs

• Boxwood -- evergreen
• American Holly (Ilex opaca) -- a dwarf variety like 'Maryland Dwarf' as the non-dwarf forms are much too big; evergreen
• Leucothoe (either Leucothoe axillaris or L. fontanesiana) -- evergreen
• Sweetbox (Sarcococca hookeriana) -- evergreen; some forms are used as a slow-spreading groundcover
• Summersweet (Clethra alnifolia) -- deciduous

Perennials

• Lyreleaf Sage (Salvia lyrata) -- native; often used as a groundcover (self-seeding)
• Foamflower (Tiarella cordifolia) -- native; often used as a groundcover (some forms produce runners, some do not)
• Jacob's-ladder (Polemonium reptans) -- native
• Golden Groundsel (Packera aurea) -- native; groundcover
• White Wood Aster (Eurybia divaricata) -- native; can self-seed into being a groundcover
• Wild Ginger (Asarum canadense) -- native; slow-spreading groundcover
• Wild Columbine (Aquilegia canadensis) -- native, though other species not locally native can also be used
• various species of fern, several of which are native
• various species of sedge (Carex), several of which are native
• Bishop's-Hat / Barrenwort (Epimedium, many species/hybrids)
• Hardy Plumbago (Ceratostigma plumbaginoides) -- groundcover
• Astilbe (Astilbe species/hybrids)
• Hardy Begonia (Begonia grandis) -- self-seeds and might become a bit weedy

Miri