Contrasting Colours in Gardens and Containers

step out of your comfort zone

Contrasting colours rather than complementary ones make a bigger impact in your garden. Most people tend to opt for complementing colors when choosing plants. I always tell my clients remember, you are not wearing the plants, they do not have to match!

Choose colours that are opposite (not next to) each other on the colour wheel (as pictured above) to create some drama.

Use Colour Contrasts in Containers Too

I love using coleus in containers for the wide range of contrasting colour in their foliage. Straight from the nursery, choose from the many options in contrasting colour combinations within the same plant! The chartreuse green of creeping jenny or sweet potato vines make the red tones of the coleus pop in your creations:

For full sun containers, I tend to go for purple, pink, red, blue and yellow for the “fillers” and “spillers.” Their bright colours look so summery and vivid against the various shades of green which are perfect backdrops for “thrillers” and additional “spillers.”

Choose Perennials with Contrasting Flower Colours but the Same Bloom Time

When choosing perennials for your garden beds, instead of picking matching colours, try selecting contrasting colours in plants that bloom at the same time. For example, this yellow ligularis in front of a purple clematis creates a much more eye-catching scenario than two yellow or two purple plantings.

contrasting colours
ligularis and clematis

Another great example in my yard is my collection of daylilies I have in a raised bed at the side of my house. From dark wine-red to pale peach, they are contrasting yet compliment each other beautifully!

Foliage with Contrasting Colours

Another trick to make individual plants stand out is to place contrasting foliage colours next to or in front of each other. An example here is the leaves of a purple smoke tree (that just had a haircut so will soon be much taller) behind (right now it looks like it’s inside) the bright green leaves of a hydrangea.

contrasting colours
purple smoke tree and hydrangea

Try some new contrasting combinations in your garden to create some drama. Be sure to send me pictures of your combinations.

Remember, forget the matchy-matchy look, you are not wearing the plants!

Thrillers, Fillers, and Spillers

When designing summer, autumn, or winter containers be sure to follow the thrillers, fillers, and spillers rule for maximum effect. The “thriller” is the center, tallest plant. The spillers go around the perimeter of the pot; choose ones that sprawl “spill” over the edges. The fillers go in between the thrillers and the spillers to fill in the bare spots.

photo credit

Annuals or Perennials?

Most people choose annuals over perennials for their summer containers. That’s because annuals bloom all summer until frost kills them off. Perennials, on the other hand, bloom for two weeks on average, if you’re lucky. You can use a combination of both for your thrillers, fillers, and spillers. For example, perennial ornamental grasses make an awesome, inexpensive (dig a clump up from your garden) “thriller” (center) for containers.

Sun or Shade?

When designing your container, be sure to take its intended location into consideration. Some plants (both annuals and perennials) like full sun, others full shade, with others somewhere in between. Don’t try to combine these different requirements in the same container. If you do, some will thrive, and others will fizzle.

You can probably tell from these pictures that coleus and hibiscus are my favourite annuals for shade and sun containers respectively….

Fertilizer

Containers of annuals can be fertilized weekly right up until frost. This practice will keep the annuals looking cheerful as long as possible. Perennials need less fertilizer, especially those in garden beds when monthly is ideal up until August (in zone 4/5).

Deadheading and Pinching

Deadheading, or removing spent blossoms, helps to keep your containers looking nice all season. For annuals and perennials with flowers on stalks, remove the stalk right back to the first set of leaves after the flower has passed its peak. This practice often encourages repeat blooming. Others just need the faded flowers picked off.

Pinching the center of annuals and perennials encourages them to get bushier instead of leggy.

Frost Warnings

While annuals will be affected by frost, most perennials will not. Some annuals tolerate a light frost, others not so much. Of course, the first frost date varies across the globe, sometimes year to year within the same area.

In other words, frost is unpredictable.

Perennials can overwinter in your containers if you choose plants two zones hardier than what is normally hardy in your area. Otherwise, you can stick them in the ground to overwinter, to use again the following spring.

You can extend the season on both ends by heeding frost warnings in your weather forecast. In the spring I tend to start my containers early to ensure I get the annuals I want. If a frost warning is issued, I move the containers into my garage, off the (cold) cement floor, for the night in question. The same technique can be used in the fall when a sporadic early frost is in the forecast.

Once frost has set in for several days, you are fighting a lost cause. It’s then time to switch your concentration to fall or winter containers. Use the same thrillers, fillers, and spillers technique to create unique designs…

Overwintering Annuals, Take Two

October blooms

A few years ago, I shared my plan to overwinter some frost-tender tropical plants from my outdoor collection. I was not successful with the bougainvillea featured in that post, but I’ve learned a lot since then, mainly from a group of experts on Facebook.

Washing Roots

It is advised (by said experts mentioned above) to shake the outside dirt off of the roots and then to give them a good rinse with a strong jet of water from your hose before bringing the plant inside. This practice loosens the root ball so the roots can stretch out in their new location.

This works especially well on houseplants that need to be repotted to larger pots too. When examining the roots of tender annuals and houseplants, remove any rotted or dead roots.

Prevent Bugs From Overwintering in Your House Too

The last thing you want to welcome into your home for the winter is bugs. Adult bugs and their eggs will come in if you do not treat the plants, soil, and roots that you bring in. I don’t mind the tiny (the size of fruit flies) buggers flying around, but my husband and grandchildren hate them.

There are several ways to eliminate both the adults and eggs. Insecticidal soap or a solution of hydrogen peroxide works well on the plants and soil. Sticky traps will catch adults preventing them from laying any more eggs. These sticky traps also work well on fruit flies.

Tropicals I’m Attempting to Overwinter this Season

This fall I pulled up three tropical plants that I used as the thrillers in containers.

I find it frustrating (and sad) that these beautiful plants are just achieving that mature, settled-in look when frost ruins them in our zone 4 to 5 gardens. This year I decided to remove the thrillers, rinse their roots with water as advised above, spray them several times with insecticidal soap, then bring them inside.

My biggest challenge was finding sunny spots for them to overwinter. My south and east-facing windows were already houseplant-loaded. It took a bit of shuffling to find spots for three (more) large plants.

Hopefully, they survive until I can reuse them in the spring.

Taking Cuttings

I also took more cuttings from fully mature annuals this fall. Like the tropical “thrillers” in the center of my containers, the fillers and spillers were gorgeous this year too. Especially the coleus, which continues to be my favourite annual for containers in shady spots.

They are all set up in perlite on my basement counter; as soon as roots form I will pot the baby plants up so I have a collection to use in spring. For those of you not familiar with perlite, it is a form of volcanic glass with a high water content, used to propagate plants without soil.

Digging up Dahlia Tubers

Another new thing I am trying this year is digging up the dahlia bulbs I planted in the spring. I have always admired dahlias in everyone else’s gardens, so decided to try them myself this year. My granddaughters loved the various colours and shapes that bloomed right up until this past week when our first frost descended on us..

I followed the same guideline with the dahlia tubers as I did for the roots of the other annuals I am overwintering. Digging up and rinsing well with a hose. The difference here is that I had to leave these lying in a single layer on the floor of my garage to dry before storing them in a box in a cool, dark spot.

Overwintering Annuals, Take Two
dahlia tubers

All of my overwintering preparations are complete, now I just have to wait until spring to see how successful I have been. Have you had any success with overwintering frost tender plants?