For Flourishing Zinnias, Don't Grow Them Near These Shrubs

Zinnias are colorful summer annuals that bloom for weeks and make great cut flowers. These sturdy growers are native to warm places like Mexico and South America and are among the most popular annual flowers for summer gardens. Zinnias make great companions for many perennial shrubs, but there are some popular plants you shouldn't grow near zinnias in the garden. For a dramatic design, place these vibrant plants among perennials that also bloom in late summer, such as sedums, asters, and mums. Growing zinnias near your shade-loving shrubs, such as hydrangeas and azaleas, is probably not a good idea. After all, these bright-flowering annuals grow best in well-draining soil in a full-sun spot.

Because zinnias need at least six hours of sunlight a day to produce the most blooms, planting them near other sun-loving plants is ideal. If you pop them into a shady flower bed full of shrubs that shy away from bright light, your zinnias may fail to thrive. Putting them in shade is a mistake to avoid when growing zinnias in the garden because a lack of adequate sun exposure can affect their photoperiod response, influencing when and how abundantly they flower. Under these conditions, your zinnias may produce fewer flowers, smaller flowers, or not flower at all. There are plenty of shade-loving annuals, such as impatiens, that you can plant for summer color, so save the sunniest spots in your garden for zinnias.

According to professional gardeners' tips, planting zinnias for season-long color is a smart idea. The zinnia genus deserves consideration when designing your summer garden. There are several sun-loving shrubs, both flowering and non-flowering, that make excellent companions for zinnias, including certain rose (Rosa spp.) varieties, butterfly bush (Buddleja spp.), rose of Sharon (Hibiscus syriacus), and panicle hydrangea (Hydrangea paniculata) — a hydrangea variety that thrives in full sun.

There are also non-flowering shrubs that love the sun and make great companions for zinnias. Evergreen shrubs rank high on this list. Try planting zinnias that bloom in your favorite pastel or vibrant colors near creeping juniper (Juniperus horizontalis). The species has spawned various blue-hued and chartreuse cultivars, including blue rug juniper (Juniperus horizontalis 'Wiltonii') and 'Gold Lace' (Juniperus x pfitzeriana 'Gold Lace'), that will contrast dramatically with your zinnias. Boxwoods also love sun — they need 4 to 6 hours of sun per day. A neatly trimmed hedge of dark-green glossy leaves makes a nice backdrop for tall, rainbow-hued zinnias.

If most of your garden is shaded, you may have to get creative about growing zinnias. You could, for example, cultivate a container garden. You can move planters full of zinnias around your yard as needed for maximum sun exposure. Afternoon sun is usually stronger and warmer than morning sun, so if your yard has limited hours of sunlight, place the containers in a spot that gets the most sun in the afternoon.