Tips for Topdressing Container Gardens
Topdressing container gardens refers to two different processes that are equally important. Most of the time, topdressing a container means covering exposed dirt with another material like rock or glass. It’s a step that most gardeners forget about but is one that can elevate an ordinary planting to something far more extraordinary. Consider it jewelry for plants.
Topdressing also refers to reviving a container plant’s soil when it becomes depleted of nutrients. However, utilizing both strategies helps to ensure that plants thrive and look their best.
Topdressing to Revive Dirt
It’s necessary to occasionally amend container garden soil because plants extract nutrients from it over time. The easiest way is to remove 1-2″ of dirt from the top of the container garden with a fork and without disturbing the root system. You may first need to water it a little in order to loosen any hard-packed dirt. Replace the old dirt with compost or another nutrient rich alternative. But rather than depositing the old useless dirt back into the yard, give it a new life by tossing into a compost bin if you have one.
Note that this form of topdressing does not involve adding additional material to jazz up the container plant. But, occasionally, this exchange of soil is what experts are speaking of when they refer to topdressing. It also is a step that busy gardeners often overlook.
Hide Dirt with Succulents
Succulents are excellent at topdressing dirt in container gardens. Container gardens tend to dry out rather quickly in Southern California sunshine so water-wise plants like succulents tolerate this better than others. Keep in mind that in order to promote good drainage, soil must be kept a bit lower than the rim of the container plants, making it potentially difficult to see low-growing succulents like hens and chicks.
Succulents fit in with a number of different gardening styles. Their usually-shallow roots mean that they can top-dress fruit trees, palm trees, other succulents and placed into busy English garden style containers both indoors and outdoors.
Add Bright Colors with Glass or Colored Pebbles
Glass and colored pebbles come in a literal rainbow of colors which opens up a wide range of decorative possibilities. The color—if any, as clear and frosted glass looks fantastic, too—can tie in outdoor furniture or add pops of color to an otherwise bland landscape. Pink crushed glass can top plants in a little girls’ room or clear class around a single plant fits well into a modern landscape.
Keep in mind that not all crushed or tumbled outdoor glass is recycled, but that it is easy to order it online.
Striking Color Contrast
Perhaps you have a bright pink cordyline growing upright in a pot. Dress the exposed dirt with blue river rock or a bright green, low-growing succulent for color contrast against the pink that packs a punch.
San Diegans can take a stroll through Westfield UTC for examples of how to do this. The popular shopping mall is now full of modern container gardens featuring a variety of color combinations in a minimalist fashion. (Tucked away in a corner near Pottery Barn is a water-wise garden full of California native plants meant to serve as a model for local homes. Check it out.)
Speaking of color, it’s important to consider the color of whatever material you’ll use for topdressing. Dark river rocks retain heat, for example, which in turn causes the temperature of the soil to dry out. This isn’t a terrible thing, especially if you’re prone to overwatering, but fragile plants won’t be able tolerate their roots becoming hot. Containers with river rock might need to avoid full sun.
Single plantings, like the succulent in the top image, benefit the most from topdressing because of color contrast mentioned above. Palm trees, flax and cordylines are popular choices for single plantings because they provide volume and/or height. Forgetting to add a topdressing is a lost opportunity to accessorize the yard, especially if there is only one plant in the pot.
Here’s a fun project for the kids, especially if your home is a beach chic style. Have them collect shells from the beach for the purpose of topdressing a container plant at home. They can also paint river rocks to top-dress a container gardens near a play area. I’ve even seen LEGO mini figures mixed into container gardens topdressings in kids’ rooms. The sky is really the limit.
Tips for Successful Topdressing
To prevent potential rot, keep topdressing away from the crown of the plant (where the stem meets the roots).
If the goal is simply to hide dirt, about an inch or two of topdressing is sufficient. There is no need to overdo it with multiple layers.
Be sure that the topdressing isn’t so dense that it prevents water from reaching the roots, especially when using shells or glass.
Topdressing also may require maintenance. Heavy rains that cause water to pool at the top of container gardens may also cause dirt to rise upward. Every once in a while, topdressings may need to be cleaned or repositioned to keep looking their best.
Tips for Topdressing Indoor Plants
Sand is often used as a decorative topdressing for succulent arrangements and small indoor container gardens. Keep in mind that once sand is in place, that watering and root growth can shift it around to where more might be necessary. This is can be messy, especially if the sand is white.
As many gardeners know, it’s very easy to bog indoor container plants with water. If plants are topdressed, they may require less frequent irrigation. Consider watering smaller indoor container gardens with ice cubes. The slow melt and portioned application helps prohibit soggy soil and tends not to disturb topdressings as much.
Moss works extremely well as a topdressing for indoor container plants because it’s easy to move out of the way when watering and reposition as plants grow. Find moss at craft stores and local nurseries in multiple colors.
How do you top-dress container plants?