April is the perfect time to plant flowers for spring and summer color. When it comes to choosing perennials and annuals there are myriad choices. For the best effect, plant combinations of perennials and annuals, as well as trees, shrubs and bulbs.
This will extend the bloom period in your garden. By including a variety of plants with different forms, i.e. spikes and mounds, big leaves and tiny foliage, etc., your garden will be even more appealing.
Consider not only the color and shape of the flowers, but the texture and size of the foliage and the plant as well. If space permits, two of three of the same variety planted in a group make more of an impact than a single plant of many different types.

When you design your garden, think about grouping plants, both foliage and flowers, of similar colors together. This will go a long way toward creating a cohesive feel.
You can apply the same principles when filling up your containers. Once the color scheme is determined, adding plants that contrast or compliment the scene will keep it dynamic and interesting.
One of the advantages of growing perennials is that, once established, they require a minimum of care and many will persist for years. Some perennials with evergreen foliage offer year-round beauty.
Although short lived, annuals are the “workhorses” of the garden, blooming for months at a time. Many also offer striking foliage when blooms are scarce.
With careful selection, you can create a landscape that offers nonstop color from spring until frost.
Here are a few combinations for spring and summer blooms. All of these will thrive in full sun, and a few will tolerate partial shade, too. Certain plants, like garden phlox, may put out a second flush of flowers if you cut them back by a few inches after their first flush of flowers.
Begonias, Caladiums and Dracaena spikes—a great annual combination for containers, they bloom all summer long until frost.
Hemerocallis (daylilies), Kalimeris pinnati da (Japanese Aster) and garden phlox (also known as Phlox paniculata)— wonderful perennials for summer color. Combine them with annuals like Angelonia, begonias and spider flowers (Cleome).
Iris ensata ‘Variegata’—a variegated Japanese iris with striking foliage and beautiful spring blooms. Site it near water for a dramatic effect, where it will look good for months. Combine it with Autumn fern and Acorus ‘Ogon’.
Perovskia atriplicifolia (Russian sage)—a great perennial “doer” that begins blooming in summer and continues well into fall. Its lavender flowers and blue-green foliage look good in combination with annual Cleome (also known as spider flower), salvias, coleus, ornamental grasses and perennial sedums.
Veronica umbrosa (Georgia Blue)—This charming mat-forming perennial is covered with medium blue flowers which begin to bloom as early as late February and continue until March. It also works well as a ground cover for small bulbs or early daffodils. Combine it with Euphorbia characias wulfenii for an addition of chartreuse flowers and blue-green foliage. For annual spring color, add violas in shades of blue and yellow.