Marianne Binetti: Clematis is queen of climbing vines and here’s how to grow one

The beginning of June is summer clematis season. This queen of the vines grows better in our cool summer climate than anyplace else in the world — so invest in a clematis plant this week and let the queen rule your garden.

EASIEST-TO-GROW CLEMATIS VINES

Purple reigns royal when it comes to which clematis do best in Western Washington. The deep purple blooms of clematis “Jackmanii” is one of the most reliable to bloom and will scramble through an evergreen and ever-boring hedge.

If you want a real drama mama plant a “Nelly Moser” and enjoy huge blooms of lavender with deeper purple stripes. The clematis ‘Montana’ varieties grow fast and large and become quite heavy so use these to cover entire sheds or building. There are hundreds of other clematis that love to grow in Western Washington. Some such as the Raymond Everson compact clematis (“Cezanne,” “Picardy”) have been bred to grow in containers. Just prune these down to two feet high each winter.

Some clematis flower in the fall such as “Sweet Autumn” clematis. The real rock stars when it comes to clematis are those varieties that refuse to be defined and just bloom all summer — sometimes early, sometimes late depending on if you get around to pruning.

SECRETS OF CLEMATIS SUCCESS

In a sentence, clematis prefer their feet to be cool and their heads to be warm. This means dig a huge hole at least two feet wide. Mix in a half bag of compost with regular soil. The compost helps to keep the soil moist and cool.

Next carefully remove your new clematis from the container. The necks or stems of clematis are very fragile. After planting, keep the soil moist and the roots cool with a 2-inch mulch of wood chips or compost.

Do not place a stone or any other heat absorbing material near the roots. Clematis grow mostly roots the first year. Buy a clematis plant that is growing in a container one gallon in size or larger. Small clematis do not transplant as easily. If you want to grow a compact clematis in a pot, chose a large container at least two feet deep.

Clematis prefer foam or plastic pots that do not absorb the heat. Make sure the container is not sitting in the afternoon sun. Fertilize every spring with a slow release plant food.

NEED A LATTICE FOR YOUR CLEMATIS?

Nope. Not in my garden anyway. In our climate clematis make a more natural display if you marry this queen to a tall and sturdy tree or shrub. Encourage the smaller more compact clematis to support themselves in the branches of hydrangeas, nandinas and Rose of Sharon hibiscus.

My favorite plant marriage is a to combine clematis with small trees such as Japanese maples. Just be sure you choose one of the smaller and more compact clematis such as those bred for containers so you don’t overwhelm the tree. Growing clematis should encourage experimentation with various other plants in your garden as supporting partners.

THE PRUNING PUZZLE OF CLEMATIS

Horticulturists debate how and when to prune specific clematis depending on what variety they are and categorize clematis into different groups and if you should prune in fall or spring or winter. Most summer blooming clematis in Western Washington can be given the pony tail cut in early spring.

Grab all the stems in one hand like making a pony tail and snip them off three feet from the ground. That keeps tidy gardeners happy as the dead leaves and tangled vines are gone but the vine will flower later in the season. Lazy gardeners can ignore this and just let their clematis climb until it gets too tall — then prune it back in the spring every few years.

Prune early spring bloomers such as the evergreen and clematis “Montana’ clematis right after they flower — but only if you think it is necessary.

WHAT ABOUT ‘SWEET SUMMER LOVE’ CLEMATIS ?

“Sweet Summer Love” is a new, hardy, small flowering clematis that is fragrant with a long bloom time. The blooms start cranberry red fading to purple and this vine blooms for months, not weeks. What’s not to love? Clematis “Sweet Summer Love” is a Proven Winners selection so it should be easy to find at local nurseries. Trust me, this is one very easy to grow clematis. I grow clematis “Sweet Summer Love” next to my favorite summer shrub — the hydrangea. I think the clematis and hydrangea union is a marriage made in garden heaven. The big hydrangea shrubs wear the violet clematis flowers like a necklace — or a crown. You can give this clematis the pony tail cut each spring to keep it compact or just let it go.

This story was originally published June 3, 2017 at 4:25 PM with the headline "Marianne Binetti: Clematis is queen of climbing vines and here’s how to grow one."