Container gardens have a host of benefits, but the main perks are that they help budding gardeners grow an array of blooms and produce both indoors and out. You just need a good container and soil to get started, but many green thumbs also suggest having stones on deck. How can you use them to benefit your plants? Here, our experts explain how to use stones when assembling your container gardens.
Add beauty with stones.
"Stones are wonderful when used as decorative accents on the top of the soil in garden pots," says Stephanie Rose, an author, master gardener, permaculture designer, herbalist, and founder of Garden Therapy. Plus, Isabelle Palmer—a city garden designer, the founder of The Balcony Gardener, and the author of Modern Container Gardening: How to Create a Stylish Small-Space Garden Anywhere ($16.50, amazon.com)—notes that using stones, pebbles, or a top dressing of bark and grit on bare compost can create a clean and fresh finish to your container garden pots.
As for their best suggestions for artful pots? While Palmer likes using large cedar bark chips (their scent is reminiscent of a forest and the brown-and-orange colors create a cultivated touch), stones have their benefits, too. She recommends using large pieces with rounded edges, such as sea pebbles, she shares: "This ensures that there is a more sophisticated finish—the worn-down look from the sea gives a naturalistic effect to your pots—but also looks modern." Rose also recommends river stones—like these from Mosser Lee ($7.30, homedepot.com)—since they emit a west coast, beach-inspired vibe. Whatever their style, the stones should be clean. "Any stones can be used as long as they are washed and free from disease or pests that could transfer to the plants," adds Rose. "Larger stones can be hosed off in the garden while smaller ones can be washed in a bucket or the sink with some biodegradable dish soap."
Fend off flies.
If you are in a constant battle with flies, Rose recommends using stones as a way to keep them under control. "Top the soil with a mix of fine sand and decorative rocks to prevent fungus gnats (which resemble small fruit flies) from laying eggs in the soil," she shares. "In outdoor container plants, rocks can be used as a heat attracting mulch on the top of the soil, so use them with heat-loving plants (like cacti and succulents)."
Improve water retention.
Palmer also recommends including hydralecca or clay pebbles, like GROW!T Clay Pebbles ($42.74, amazon.com), at the base of a container (fill it about one-fifth of the way up). "The pebble barrier stops the evaporation of water from the soil," the expert explains. "They are a great way to absorb excess water in a container, but also to release water when the pot is drying out. This combined with a top dressing is a natural way to aid your plant's water consumption."
Ensure proper drainage.
Jessica Walliser, a horticulturist and the author of Container Gardening Complete ($25.34, amazon.com), notes that while gardeners have placed gravel, stones, and broken pot shards at the bottom of container garden pots for generations, this practice can actually limit drainage—so be careful of their placement. "Water doesn't easily move through different textured materials, so when you put water in the top of a pot and it filters down through the fine-textured potting soil and hits the coarse-textured gravel or pebbles, the need to transition from one texture to another serves as a roadblock to the water's movement," she explains.
A good way to prevent this type of roadblock? Choose a pot with a drainage hole—or make your own. "Use a cordless drill, fitted with a bit that's appropriate to whatever material your pot is made of—like RYOBI 18-Volt ONE+ Lithium-Ion Cordless Drill ($79, homedepot.com)—and open at least one half-inch drainage hole in the base of the pot," Walliser adds.
FAQs
The only reason to put a rock in the bottom of the planter is to cover the drainage hole and keep soil from coming out when you water your plant. Only use one rock per drainage hole.
Why do people put rocks in plant pots? ›
The only reason to put a rock in the bottom of the planter is to cover the drainage hole and keep soil from coming out when you water your plant. Only use one rock per drainage hole.
Is it okay to put stones around plants in pots? ›
Preventing insects from entering the soil
The use of potted stones will destroy the suitable substrate for the growth of insects and pests, and they will no longer be able to live inside the pot, thus damaging the plant. Using these stones is better than spraying for pest control.
Why do people put rocks around plants? ›
Basically, rocks give soil something to hang onto, which is very useful in heavy rains or times when there's significant water runoff. How nice that these serve a real practical purpose as well as an aesthetic one, too.
Should I put rocks in the bottom of my cactus planter? ›
Rocks in the bottom of containers do not contribute to better draining soils and healthier plants. Instead plant roots encounter saturated soils that don't drain efficiently.
Do rocks help with fungus gnats? ›
One of the easiest and most effective ways I have found to eliminate the gnats is to put a shallow layer of landscape rocks on top of houseplant soil. The baby gnats are not able to emerge from the soil, and the adult females cannot return to lay eggs.
What is the best rock for drainage? ›
We offer quite a few great options with bulk delivery right to your driveway, so it's not surprising customers need help choosing. The fact is that pea gravel is the best gravel for drainage. It's unique size and shape and loose structure allows water to flow through it without issue.
Can I put rocks on top of soil in potted plants? ›
Rocks and gravel scattered in a thin layer on top will also help keep water inside the soil by reducing evaporation from the surface.
Are stones bad for plants? ›
However, stones aren't the perfect solution for gardens that may get a lot of sun because they can hold more heat than mulch. This will dry out the soil underneath. Also, growing plants and trees from a stone top base can be challenging, as the stones don't add any nutrients to the soil.
Which is better, mulch or rocks? ›
Mulch made from organic material like bark or wood chips decays over time, crumbling into nutritious bits that actually feed your soil. Rocks don't add anything to the soil. So plants that grow in beds mulched with rocks may need extra fertilizing.
Pumice stone is a favorite stone mulch for many landscape experts, for its water retention properties and its attractive dark gray color. Usually black or reddish, larger lava rocks are very dramatic, good for dressing a garden bed or creating a focal point.
What is the best rock for a flower garden? ›
Bricks, river rocks, and flagstone are excellent for accenting flower beds. They'll also work to create a path to a gazebo or serve as a wall around your garden. All these materials are only a stone's-throw away.
Why should you not put rocks in the bottom of a planter? ›
Therefore, when you add gravel or other coarse materials to the base of your pots, water lingers around plant roots instead of draining, which increases the likelihood of root rot developing.
Do I need stones in my plant pots? ›
If your pot has drainage holes of more than about 2.5cm (1in) in diameter, place some stones or crocks (broken terracotta) over them to prevent compost falling through. If drainage holes are small, there is no need to cover them.
What to put in the bottom of a planter without drainage holes? ›
“If your planter doesn't have holes, you can keep the plant in its grow or nursery pot and place it inside the planter you would like to use,” he says. You can also place gravel or pebbles in the bottom of the decorative pot and place the functional pot with drainage on top of that layer.
Do rocks prevent plant growth? ›
Small rocks can improve soil drainage and aeration by preventing compaction. However, large rocks can hinder root growth, make planting and cultivation challenging, and increase the risk of injury when working in the garden.
What is the best thing to put in the bottom of pots for drainage? ›
One of the best things to put at the bottom of a planter for drainage is broken pieces of pot. You can use any unwanted plant pots or chipped crockery for this – simply smash them up into small to medium-sized pieces. Adding a layer of broken pieces of pot like this will prevent compost loss out of the drainage holes.
Do rocks help with drainage? ›
The permeable nature of landscape rock also aids in minimizing puddling and standing water, creating a visually appealing and functional drainage system for gardens and outdoor spaces.
Why are rocks important to plants? ›
It is recognized that rock powders can be a source of plant nutrients, mainly by supplying P, K, Fe, and Si, as well as trace nutrients to the plants (Ribeiro et al., 2020). Rocks also have the capacity to raise the pH of the soil, acting as correctives of acidity and releasing other nutrients, such as Ca and Mg.
