Cinder Block Planter Ideas: What to Plant and How to Style Them

Cinder block planters are one of my favorite inexpensive ways to add character to a yard. I’ve built them in our front, back, and side yards over the years, and they never disappoint! They’re one of those projects that look a lot more intimidating than they actually are. In reality, they’re completely beginner-friendly! If you’ve never built one, head over to my step-by-step tutorial for all the details. But if you’ve already made some and are wondering how to take yours to the next level with plants, paint, and finishing touches, this post is for you! From the best plant pairings to an annual refresh, here are my favorite cinder block planter ideas to help you make them your own.

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Cinder Block Planter Ideas Part 1: The Thriller, Filler, and Spiller Technique

I love plant shopping, and over the years, I’ve figured out which plants seem to thrive in cinder block planters.

Since cinder block planters have a bit less soil space, tend to dry out more quickly than in-ground beds, and are often placed in full sun, choosing the right plants can make all the difference. But you don’t have to overthink it! One of my favorite ways to put together a planter is by using the classic “thriller, filler, spiller” method. It sounds fancy, but it’s really just a simple formula for creating balance.

Thrillers add height, fillers create fullness, and spillers cascade over the edges to soften the look of the planter. It’s an easy trick that makes even beginner gardeners feel like they know what they’re doing. I’m including some of my favorite combos/vibes below!

Bold Color: Zinnias, Marigolds, and Sweet Potato Vines

I might be biased because zinnias are one of my favorite flowers. But apart from my own love for them, they’re also pretty easy to grow and love the sun. Since they’re taller flowers, they add some nice height to the planters. And the marigold and sweet potato vines complement the brightly-colored zinnias so well!

English Garden: Delphinium, Calibrachoa, and Creeping Jenny

This grouping reminds me of an English cottage garden! The colors are more subdued, but the shapes add whimsy. Just note that while Creeping Jenny is a great choice for planters, it can be tricky to get rid of when it’s used as ground cover.

Pastel Pollinators: Snapdragons, Pink Petunias, and Sweet Alyssum

Bumblebees and hummingbirds love snapdragons! And petunias bloom from late spring to early fall, making them a great choice for keeping your planters beautiful throughout the seasons.

Remember:

The thriller, filler, spiller formula isn’t something strict you have to follow. Like they say in Pirates of the Caribbean, “it’s more what you’d call a guideline than an actual rule.” 😆

Supplies:

Cinder Block Planter Ideas Part 2: Veggies and Herbs

One of the biggest advantages of cinder block planters is that the blocks absorb heat from the sun, which can help warm the soil and give warm-weather vegetables a boost. Here are a few veggies that do great in planters, plus some options for your very own herb garden!

Lettuce & Spinach

These have shallow root systems, so they tend to do well in cinder block planters!

Green Onions

This kind of onion doesn’t take up too much space to grow, and they can even be regrown from leftovers.

Cinder Block Planter Ideas: Peppers

Peppers love the warmth (same), making them ideal for full-sun planters.

Bush Beans

These are perfect for beginner gardeners.

Herbs: Basil, Thyme, Rosemary, Parsley… You Name It

I recently made an indoor herb garden, but in the summer, why not take it outdoors? Herbs are fairly easy to grow, and they thrive in containers, making them an awesome choice.

Cinder Block Planter Ideas Part 3: Polish the Planters

After a long Utah winter, my planters are usually in need of a touch-up come spring. These are some of my favorite ways to give them a quick update!

Paint

I painted all of my cinder block planters black, and I absolutely love how it helps them blend in with the rest of our landscaping. Since they’re exposed to the elements year-round, I like to do touch-ups each season to keep them looking fresh.

Cinder Block Planter Ideas: Planter Fences

I added these little planter fences last year, and they’re a fantastic finishing touch! They add so much charm and instantly make the planters feel more custom. They’re also incredibly easy to DIY, and you can stain or paint them to coordinate with your home’s exterior. Bonus: If your planters sit against your house (like mine do in the front yard), the fence helps disguise the foundation!

Solar Lights

At night, solar lights create a warm, welcoming glow that makes your yard feel a little more magical. Tuck spotlights between larger plants to highlight them, or line the planter with small stake lights for ambiance and lighting along pathways and gathering spaces.

Mulch & Plant Maintenance

Never underestimate the power of a fresh layer of mulch! It can make a planter look completely refreshed. You could even spray your mulch with this for a fast update.

I also try to stay on top of trimming plants, deadheading flowers, and pulling out plants that have seen better days. A little maintenance here and there goes a long way!

Fairy Garden

I had to include a fairy garden because they’re just too adorable not to mention. I recently created one for my daughters in a raised planter, and I can only imagine how much fun I would have building one with even more space. Fairy gardens pair beautifully with just about any plants, but tucked into the English garden-inspired trio above? So. Cute!

I hope these cinder block planter ideas gave you inspiration for your dream garden!

Because you deserve to have an outdoor space you love and feel proud of, at any budget. Be sure to check out my full planter tutorial and to tag me in how they turn out!