Keeping It Cool In The Garden With Summer Whites - A guest post by Christine Wegman

The great Impressionist artist, Monet, was also a well-known and respected gardener.  It has been said of him that, had he not been a great painter, he would nonetheless be known today as a great landscape designer.  He corresponded with Gertrude Jekyll in England and many other famous landscape designers of the day.  His restored garden at Giverny attracts thousands of visitors every year.

Monet used his artist’s sense of color to design his garden, and the garden in turn provided a favorite subject for his paintings.  Most of Monet’s signature color schemes at Giverny included white flowers.  He liked to have sprinklings of white to give a sparkling effect to an array of colorful flowers.  White, of course, is the coolest of cool colors, and drifts or sprinklings of white will give a refreshing, cool effect to any garden on a hot day.  Below are some ways to bring white into your garden.

Shade Garden Whites.  I like to look for white, or near white, in foliage because it will endure throughout the growing season. 

hosta

In a shade garden, nothing could be easier to achieve.  There are any number of green and white hosta, such as Hosta ‘Undulata Variegata’ with white centers or Hosta ‘Undulata Albomarginata’ with white edges.  Newer varieties include ‘White Feather’, ‘Brim Cup’, ‘Fire and Ice’, or smaller-leaved varieties like ‘Diamond Tiara’ and ‘Ginko Craig’.  Japanese painted fern, although more silver than white, will give the effect of white and looks lovely with hosta.  Brunnera ‘Jack Frost’ will sparkles   Add some green and silver variegated coral bells and an annual green and white caladium or two and you will have a very cool and showy shade garden. 

Caladium

Many shrubs have variegated varieties.  Hydrangea macrophyla ‘Mariesii Variegated’ is a beautiful choice.  The leaves are variegated with white margins and the flowers are lavender with large white sterile blossoms at the edges.  Pieris japonica ‘Variegata’ is another effective choice.  

Variegated leaved plants are not usually as vigorous as the plain-leaved cultivars, but their advantage is that they will usually stay compact.

hygrangea

For long lasting white flowers in the heat of summer, there is just nothing like hydrangeas.  For the shade garden it’s hard to beat our native Smooth Hydrangea (Hydrangea arborescens).  ‘Annabelle’ is the most popular cultivar and will grow in sun or shade.  There are also a number of mactophylla or French hydrangeas that have white flowers.  ‘Fuji Waterfall’ is a particularly beautiful example with star-like pristine white blossoms. 

Sun Garden.  In a sunny garden, you must depend more on flowers than foliage for a cool effect.  Still, with a little planning, you can have white flowers all through the summer.

Summer flowering trees and shrubs provide long-lasting effects with less care than perennials or annuals. Among the most beautiful flowering trees are Southern magnolias, with their velvet white flowers and their wonderful lemon scent.

magnolia

  White crape myrtles, especially, are long-blooming and easy to grow.  The most popular are probably the best: Lagerstromia ‘Natchez’ and L. ‘Acoma’.  Although ‘Natchez’ is the most widely planted crape myrtle in the country, at a 20-foot mature height it is a splendid tree with beautiful cinnamon bark that stands out in winter.  For a slightly smaller white crape myrtle, ‘Acoma’ tops out at about 16 feet and has lighter bark that looks pinkish in winter.  Both have an overall umbrella shape that always looks graceful.  I have a row three ‘Acoma’ crape myrtles at the back of my garden.  They are under-planted with ‘Annabelle’ hydrangeas, hellebores, and green and white hosta.  They look cool in summer, and attractive throughout the whole year. White crape myrtles, especially, are long-blooming and easy to grow. 

oak leaf hydrangea

Among shrubs the mainstays are, again, hydrangeas.  Our sun loving native oak leaf hydrangea (Hydrangea quercifolia) has white panicle shaped blooms in June.  They fade to pink after a few weeks and when the flowers are spent you are left with the beautiful oak leaf shaped foliage that turns red in fall, and for which the plant is named.  Later in the summer the panicle hydrangeas (Hydrangea paniculata) put on their show.  The old PG hydrangeas, short for Hydrangea paniculata ‘Grandiflora’,  are the best known, but many newer and smaller varieties widely available.  ‘Limelight’ grows 6-8 feet high, but can be kept within bounds by pruning back to the ground in late winter. 

Another white flowering shrub worth mentioning is the old favorite, Rose of Sharon (Hybuscus syriacus).  My favorite is the National Arboretum introduction, ‘Diana’, with pure white flowers that bloom from July to September.  This is an easy shrub to grow and when the blooms are spent, they fold themselves up neatly and drop off the bush.  No need to clip off spent flowers. 

There are plenty of white flowered perennials that make a garden look cool in summer heat.  My particular favorites are lilies and summer phlox. 

phlox

Anemones

Summer phlox (Phlox paniculata) is a long-blooming staple of many summer gardens.  It is prone to mildew in our hot climate and needs a lot of air, so it is best planted in a fairly open situation.  I have found that it does well in dappled or afternoon shade.  ‘David’ or ‘Mt. Fuji’ are two mildew-resistant varieties, whose gleaming white flowers immediately draw the eye.  Lillies can be planted in small groups among shrubs and perennials to give the sparkling effect Monet valued.  Among the most beautiful whites are the oriental lily, ‘Casa Blanca’, and the newer LA hybrid lilies that bloom earlier than ‘Casa Blanca’.  There are a number of good whites, including ‘Bright Diamond’.  Regal lilies, while not pure white, add a classic touch to any garden.  Visit Brent and Becky’s Bulbs on the internet to find a good selection of high quality lilies. 

Cleome

If you don’t have as much white as you would like, there are plenty of annuals that will instantly produce the effect you want.  Plant annual white flowered euphorbia at the edges of a flower border, or plant some white cleomes further back to add a little sparkle.

There are lots of ways to incorporate white into your summer garden, many of them quite consistent with low maintenance.  Even a few touches of white throughout the summer will provide a refreshing foil for hotter colors.  Once you start looking for whites, there are literally hundreds of choices. 

peony

Christine Wegman is a Rock Spring Garden Club member in National Capital Area Garden Clubs' District III.  She is one of the go-to 'hort' experts in her club. Christine and her husband, Charlie Flicker, are avid and generous gardeners and have cultivated a delightful garden (for any season) in Arlington, Virginia.