I am fascinated by hues of blue: sapphire blue, cerulean blue, azure and periwinkle. Blue is one of my favorite colors, so I guess it's no surprise that I like to grow blue plants too. Morning glory, Virginia bluebells, bluestar and blue lobelia all find a welcome home in my garden.
Blue plants are in the cool range on the color wheel. They work well with their color opposites in the yellow to orange range; contrasting blue and white makes a nice combination as well. The artist Monet was fond of blue plants. 'Monet's Blue' iris was named in his honor.
In my quest for blue plants, I've developed a fondness for blue pots and blue garden accessories. My pupils dilate whenever I see blue glazed pottery. Luckily, I picked up a few pots at a July 4 sale for 70 percent off. You'll be seeing quite a few plant and pottery sales now that the peak of the gardening season has passed.
As I plan my "true blue" garden over the next few years, I'll be adding most of these plants, many of which already grow happily in my garden:
Blue Hydrangea. Recently, I visited Chanticleer (the "pleasure garden" in Wayne, PA), the perfect spot to admire the many hydrangeas in shades of pink, purple and blue. Personally, I love the soft blue colors of the lacecap hydrangeas that have a flattened flower head encircled with small florets. 'Blue Billow' is a popular lacecap hydrangea. 'Nikko Blue' is a popular mophead variety with its large blue ball-shaped flowers.
Even if you purchase 'Nikko Blue' or 'Blue Billow,' hydrangea, remember that the color is dependent on the acidity of the soil. If your plants aren't blue enough and have pinkish tones, add some aluminum to the soil in the form of aluminum sulphate. Follow the instructions on the bag in order to lower the pH of the soil. Or try adding compost amended with coffee grounds, or an acidic organic mulch such as pine needles or shredded pine bark.
'Heavenly Blue' morning glory. The name says it all. As this annual morning glory vine reaches for the heavens, it seems to reflect the bright blue sky. You can purchase a packet of seeds to start your own vines, or you can buy some vines at your local garden center. If you're a lazy gardener, you won't need to sow seeds every year. Simply let some of the flowers set seed and you'll have vines popping up in your yard next year. Since 'Heavenly Blue' is a hybrid, the flowers will be purplish, but you'll have free plants! Use these climbers with attractive heart-shaped foliage to cover a trellis or fence in a sunny area. Morning glory attracts hummingbirds, butterflies, bees and other pollinating insects.
Jacob's Ladder (Polemonium species). This underused spring-bloomer thrives in shady areas. It is understated but regal with its fern-like foliage and beautiful bluish flowers. The leaflets appear ladder-like on each side of the stem. There are many beautiful cultivars including 'Stairway to Heaven' and 'Snow and Sapphires.'
Other blue plants include annuals such as lobelia, 'Blue Daze' Evolvulus, and 'Black and Blue' Salvia. Look for 'Techno Heat' on the lobelia plant tag. These new heat-tolerant hybrids are said to perform better than the non-hybrids in warmer temperatures. Lobelia lovers know that these plants prefer cooler temperatures and tend to stop blooming when the temperatures heat up. So far, the heat-tolerant lobelias that I purchased this year are blooming up a blue storm!
Blue perennials include delphinium ('Blue Butterfly' stopped me in my tracks a few years ago), blue hosta (such as 'Blue Angel' or 'Big Daddy'), bluestar (Amsonia species), blue flax (Linum sp.), lungwort (Pulmonaria sp.), Virginia bluebells and forget-me-nots. Blue ornamental grasses have names such as 'Elijah Blue' fescue, 'Heavy Metal' and 'Prairie Sky' switch grasses and blue oat grass.
Add some blues to your garden to cool down the hot yellows, oranges and reds!