DIY Container Gardens

Relish Realty
Published on May 16, 2020

DIY Container Gardens

I have a bit of an obsession with flowers (the day the seed catalogs come mid-winter is officially a holiday in my house) and I love to mix-and-match annuals for summer-long color. When I worked at The Bruce Company, I learned how to put properly structure the ever-popular container garden. I loved the ones we got in, but often wanted a different combo of plants or balked at the price tags or didn’t like the pots….something just wasn’t exactly as I wanted it. So I started making my own following a pretty simple mantra: Thrillers, fillers, and spillers. 

Freshly planted – remember things will get *much* bigger

Pots and Soil

Before we get to the good stuff (FLOWERS! PLANTS!), you’ll need to get the basics covered – pots & soil. 

Pots & containers are the best place to start. There are endless choices in size, shape, and material and they all have pros & cons. Generally speaking: Plastic containers can be left out & filled with soil all year, ceramic/terra cotta should be emptied and moved into a garage or basement to avoid cracks, and metal containers can stay out but may rust or have the finish flake off. For wood, cedar is the longest-lasting and most readily available, but if you don’t like the faded silver patina that it develops, be prepared to break out the stain every few years. You can also do painted wood (again, needs upkeep) or go for the classic whiskey barrel – low-maintenance and will last for years. Generally speaking, I don’t worry about bringing my wooden planters indoors during the winter. I also have deck railing planters that I absolutely love and keep out all year – I do bulbs in the spring & plan to do greens this winter for the first time. 

Potting soil is important – annual plants take up a LOT of nutrients to keep those blooms coming all season, so you should plan to start with a good quality soil mix that has built-in fertilizers/compost and replace it every few years. The constant watering leaches out the nutrients, and the plants take up the rest. (Even with the good soil mixes to start, you’ll want to fertilize regularly). I like Jung’s potting soil, but most nurseries carry something suitable. 

Those containers can be huge and get SUPER heavy to move around – and it’s expensive to fill them with all that soil! – so I grab (clean) plastic bottles from our recycling bin to fill in the bottoms of the larger ones – just be sure to leave about 8″ of soil for the plants. There are products you can buy to pop into the planters to raise the soil level, too, but I chose to just reuse something we’d already had. 

Picking out your plants

Now for the fun part: Designing your containers and picking out the plants! 
Just remember: You need thrillers, fillers, and spillers. This is a great way to make sure you have a container that is well-balanced and pleasing to the eye. Thrillers are tall, eye-catching, and create a nice backdrop for the rest of the plants; generally, they go in the center of the container. Fillers are medium/lower height plants and typically have terrific flowers or attractive foliage. Spillers are placed along the edges of the container and trail down the front/sides and provide a good anchor for the entire package. 
Some of my containers I keep on the simple side (we’ll do a post about DIY whiskey barrel planters down the road), and others I do a big ol’ mix of whatever catches my eye at the greenhouse. These are my favorite containers and I look forward to shopping for plants for them all winter long. Did I mention I love plants? 

On Mother’s Day, I hit Klein’s on East Wash and loaded up with this year’s container flowers. From my winter dreams, I knew I wanted to build my deck planters around some fabulous black petunias and do something lighter & brighter for the front of the house, so I headed to the specialty petunias to start grabbing some of my ‘Fillers” for the deck boxes. 

Black Petunias

I generally like to pick contrasting colors for eye-catching displays, but try to limit to 4-5 colors that both blend and contrast well. For this year’s deck boxes I did blacks, blues, light purples, dark pinks and white. Don’t forget to layer your greens, too, as they have a big impact on the overall feel as well. I try to pick some plants with lighter-colored foliage to help brighten things up.

For our front planters, I wanted them to be a little less complex since I have a huge pollinator garden along my front walk. Also, since our front door is more in the shadows/set back, I wanted to brighten things up a bit. Here I went with whites, bright lime-y green, light blues, and bright pink. 
Klein’s Greenhouse has an incredible selection of annuals, even this year, and they are following solid social distancing practices. I was able to get everything I wanted (and then some) for all my containers. 

If you want to keep the cost down, look for 4 packs of as much as you can and then mix in a few of the specialties in 4-5″ pots. For me, I loaded up on black petunias and a few of the other specialty petunias, but then added in 4 packs of the ‘regular’ ones to help stick to a reasonable budget (Well…somewhat reasonable. Did I mention I love plants WAY TOO MUCH?).  At any rate – 4 packs are still gorgeous and much easier on the wallet.

Ready to hit the Greenhouse?

Here are some of my favorites:
Sun Thrillers – Elephant ears  (for very large containers), guara, eucalyptus, black & blue salvia or other tall salvias, purple fountain grass, spikes, carex grasses, 
Sun Fillers – sun coleus, petunias, geraniums, nemesia, lobelia (can also be a spiller), marigolds, million bells (can also be a spiller), dusty miller – this is really the easiest category to find things! 
Sun Spillers – sweet potato vine, ivy, vinca, trailing pentas 

Black & Blue Salvia, my favorite ‘thriller’

Shade Thrillers – Spikes, caladium, upright fuschias (Gartenmeister, Firecracker), Angel Wing begonias, carex grass, dracaenas 
Shade Fillers – shade coleus, impatiens, tuberous & cocktail begonias, trailing Fuschia (can also be a Spiller), oxalis, lobelia, polka dot plant
Shade Spillers – creeping Jenny, trailing fuschia, Lysimachia “Sunburst”, lobelia 

As you pick things, keep an eye on the tags to make sure you’re mixing heights appropriately for both the container size & compared to the other plants you chose. My front step containers are not large and I didn’t want huge plants, so I chose tall snapdragons for my thriller (24-36″), fillers that will get 12-18″ tall (sun coleus & lobelia) and a spiller that will truly trail down the front (sweet potato vine). If they were bigger I’d have gone with larger plants and a greater variety most likely. My deck boxes aren’t huge, but since I have so many & they are not competing with other gardens, I do a larger variety.

This year my fillers were black petunias, dark pink, light purple, and white petunias and a few white snapdragons, my spillers are chartreuse & purple sweet potato vines, and my thriller black & blue salvia (butterfly & hummingbird magnet) and eucalyptus. I have never done eucalyptus before, so not sure how it will fare yet -but I couldn’t resist the silvery foliage and crisp scent. 

Freshly planted deck boxes

There really are only a few rules for container gardens: Make sure you love the plants you chose, pick the right plants for sun/shade, and don’t forget to water (daily in the hottest part of the summer) and fertilize (weekly…if you remember).  Happy planting!