The Easy Beginner's Guide to Container Gardening

So you want to add some greenery at home and you're ready to dip your toe in container gardening... but where do you start? Honestly, it’s as easy as grabbing a pot and just starting! If a garden—as in digging up the earth and planting seeds—feels intimidating, or you don’t necessarily have a green thumb, container gardening is a low-stakes way to bring flowers, greenery (and maybe even food!) to your outdoor space—even if your outdoors is a balcony. 

To help you kick off your container garden collection, we went to experts with a combined total of 75 years of experience, who offered beginner-friendly pointers and tips for lush planter pots.

What is Container Gardening?

Amy Zinner, a Louisville-based professional gardener who designs potted "plantscapes" for residential and commercial spaces, says you should think of growing plants, flowers, vegetables, and herbs in containers as a “way to design your space with nature."

But what exactly constitutes container gardening? Simply put: “It's plants grown in pots or suitable containers above ground rather than in the ground,” explains Jan Phipps, a retired farmer who served as master gardener at University of Illinois Extension.

What are the Benefits of Container Gardening?

For people without a lot of outdoor space available—say, anyone living in an apartment or condo—or those with unsuitable soil, container gardening is a great way to add “color and texture to porches, patios, and balconies,” says Phipps. But you’re not limited to those spaces! 

Raised beds are also considered container gardening, according to Zinner, and artful arrangements of containers can beautify your home entry or back yard.  Buying pots and potting soil (more on that in a minute) is a pretty low barrier of entry, especially for anyone without much gardening experience. 

How to Start Container Gardening

Select the Right Containers

Anything from an old pair of boots to a wine barrel can technically be home to a growing plant, but conventional containers come in the form of pots. These can range from plastic to concrete and they each have their pros and cons. 

“I do believe in starting with a high quality pot and high quality soil, because it just sets you up for success,” Zinner says. She prefers a glazed ceramic, which will stand up to winter weather, while Phipps calls terra-cotta her favorite, because it’s porous. 

While plastic pots are light and easy to move, not to mention less expensive, Zinner never uses them. Why? “Because it looks like plastic!” she says. “If you're going for beauty, you don't want to put [plants] in a pot that doesn't match their beauty.” Concrete can be heavy and hard to move but is useful for plants with a big canopy that can blow over easily, says Phipps. 

No matter your pick for the container, the key is that it provide drainage. “If there's no place for water to go and drain out, that plant is going to drown," Zinner says.

Choose the Best Soil Mix

There’s no need to over-complicate things when it comes to soil, the experts say. Advanced gardeners may want to experiment with creating their own combinations, but the work is done for you with the pre-packaged stuff. “They've already given you the proper mixture of nutrients that plants need to grow and thrive,” Zinner says. 

What you don’t use, says Phipps, is plain old dirt. “You'd never ever use topsoil or something you'd shovel out of your garden. When it dries out, it shrinks and it comes away from the sides of the pot,” she explains. “Then you can't water it because the water runs down between the root ball and the side of the pot.

Zinner’s go-to for her professional designs is Miracle-Gro. “It's so tried and true,” she says, “and it's a good value.” While it may not guarantee your success, she adds, “it gives you a better head start.”

Pick Suitable Plants

So what should you plant? With the world of plants available, it helps to start with a recipe for design, Zinner says. The formula, according to both experts, is known as thriller, filler, spiller. 

“The thriller is your statement plant, says Zinner. It’s “going to be your tallest piece. It's going to be your most eye-catching plant, and there's only going to be one.” A canna lily is a good example of a thriller, she says, and often it will be in the center of the pot.

The filler, like it sounds, is a small plant that “fills in that space between the top of the thriller and the bottom of the pot,” Zinner explains. (Lantana is a solid choice.) “And the spiller is going to be the plants that go in last that cascade around the bottom of the pot,” she says, with petunias being a great option.

You’re not limited to plants and flowers though. Small tomatoes, herbs, even cucumbers can grow in containers.

Annuals vs. Perennials in Container Gardens

While you can grow either annuals (plants that only last the season) or perennials (plants that return yearly) in containers, annuals are where you get the biggest impact. They bring color immediately and can grow big quickly. They’re also less expensive, though you do typically have to replace them every year. 

The rule of thumb here, Zinner says, is to stick with one or the other in any individual pot. “If you think about what's going on below the surface, once a plant is established, the roots just go every which direction,” she explains.

“So if you put a perennial in a pot with, say, two annuals, and those annuals die, well, you're going to disturb that perennial when you go to pull out those annuals and then you're going to try to put a new plant in there that's going to compete with the root system of the existing perennial.”

How to Water Container Gardens

The general rule for watering container gardens, says Zinner, is “that you want the soil to be moist; not wet, not dry.” While she sometimes uses an inexpensive water meter, her easy trick is to put her index finger into the soil down to the second knuckle. “If I feel moisture, then the plant is happy,” she says. “If it feels dry, it needs water.” Zinner recommends watering in the morning so it has time to dry before night (which could create mildew). 

Phipps adds that you should “water the soil, not the plant.” In other words, she continues, “don't just dump the water over the top of the whole container.” Getting the plant wet can lead to disease.  “It's better to stick your watering can or hose through the plants. And you want to moisten the entire soil volume,” she instructs—not just the top few inches.  

And don’t worry about irrigation, both experts say. That’s an advanced and costly method of watering not geared toward beginners. Your plants will be just fine without the fancy stuff.

Fertilizing Container Plants

Plants need nutrients, and while you don’t have to fertilize them for a successful garden, Zinner says, she does. Her favorite product is Osmocote. “I fertilize when I plant the pot, and I just follow the directions on the bottle,” she says. “Basically you shake the fertilizer onto the soil and then you use either your fingers or a little prong tool to work it into the first one to three inches of soil.” 

Phipps suggests buying a ready-made fertilizer as well, noting that there are organic and conventional options. The difference? “Organic fertilizers usually work by bettering the soil [which] can feed the plant,” she says, while “conventional fertilizers put nitrogen right in the soil and the plant can take it up immediately.” It comes down to personal preference, she says. “Both work.”

Container Gardening Maintenance

To enjoy your container garden all season long, it’s not just a one-and-done job. This is part of the fun though! “I love watering,” Phipps says. “I like having a reason to get outside every day. I like the mothering of it, the tender caring and the shaping, and I like moving them around so they they look different. Or I like starting with a tiny little start and watching it grow and then moving in the living room for the winter and then moving it back out.”

Part of that maintenance includes deadheading. Not the nicest sounding word, but it’s a nice thing! “When a bloom is spent, pinch that off,” Zinner says, “because [that’s] going to allow the plant to send energy to the next round of blooms.”  You can also prune the plant, trimming back the top edge to allow it to grow in bushier, she says. 

Keeping an eye out for pests is another job, but luckily, “there are surprisingly few [pests] with container gardens outside, Phipps says. In nature, “the good insects eat the bad insects and everything keeps balanced,” she says. The possible exception is Japanese beetles, she says, and for those, "you just keep an eye out and pluck them off."

Winterizing Container Plants

All good things come to an end. But when the season is over, your container garden doesn’t necessarily have to be over, too. Unless you live somewhere with year-round sun, they do have to move indoors, or at least into a sheltered area if your part of the country is warm enough.