As city dwellers, we never seem to have enough of two things: space and time. So when the growing season beckons, what’s a busy urban gardener to do? Growing edible crops in pots may be the answer.
Planting in containers is a relatively easy task, and one that affords a lot of freedom and flexibility, especially when compared with the hours it takes to prepare and plant a traditional garden plot.
Choosing the right location for a traditional garden is critical, but with container gardening, “you can have your garden adapt to you,” says Nathan Gerber, an advanced master gardener based out of the Utah State University Extension Office at Thanksgiving Point.
Carving out a plot that provides vegetables with a minimum of six to eight hours of daily sunshine may be a challenge, but if the location of your container garden isn’t perfect, all you have to do is move the pots.
What you need • In its simplest form, growing a successful container garden requires only six things: seeds or starts, suitable containers, consistent moisture, container soil, regular fertilization and full sun. Given these basic necessities, vegetables that are traditionally grown in the ground can be grown in pots instead, with few exceptions. And your choices aren’t restricted to “bush,” “compact” or “determinate” vegetables, either. Although these varieties have been bred specifically to grow well in small spaces, full-size vegetables will also thrive in pots as long as they are treated well.
Just about anything can house a vegetable, but the containers you use must be able to sustain the crops you plant: asking a full-size tomato to bear fruit while living in a one-gallon container is an unreasonable demand, and you will be disappointed. At minimum, full-size tomatoes need three-gallon pots, and bigger is always better.
“Put your money into pots that are a little bigger and put your money into [quality] soil — you’ll have much better success,” Gerber said.
What constitutes a pot is really limited only by your imagination, but two things that all containers must have is good drainage and planting medium that holds moisture well.
These are non-negotiable. If soil becomes waterlogged and cannot drain freely, plants’ roots suffocate. However, giving plants too little water is not the better option: dehydrated, heat-stressed plants will expend their limited energy merely trying to stay alive, which will drastically reduce your potential harvest.
The key is to find balance, and the best test of that is your finger: push it about two inches into the soil. If your fingertip feels damp, your plant is wet enough. If the soil feels dry at this level, water your plant until water drips from the bottom of the pot.
Although many traditional pots come pre-drilled with at least one large hole, any container you choose can be given sufficient drainage with the right drill bit. After adding one or more ¾-inch holes to the bottom of your container, you can use a fine mesh, such as window screen cut to size, to line the pot. This will let excess water out while keeping precious container soil in.
Toil over soil • Having enough soil is critical to your success as a container gardener, as is choosing the right type. The term “potting soil” is a bit misleading, as most potting-soil mixes are soil-free. Strange as this sounds, soilless mixes are ideal for containers.
Katie Wagner, extension assistant professor of horticulture at USU, says containers should be filled “with a top-quality growing mix containing any of the following: sphagnum peat moss, perlite, vermiculite, coarse/sharp builders’ sand and fine bark.” The ingredients in soilless potting mixes help the mixture to stay fluffy and retain moisture, which gives your plants’ roots plenty of breathing room.
Soilless mixes are also sterile, which means they’ll lack any little nasties (soil-borne diseases, pest insects, etc.) lurking in your traditional garden soil, and they allow complete control over the nutrition you give to your plants. Because many mixes contain no added fertilizer, you can easily group plants that require the same types of nutrients in the same pot and feed them all at once.
Wagner suggests that container gardeners “add slow-release fertilizer at the time of planting, which will last approximately 2 months, or use a soluble fertilizer and apply it according to the label.” Giving your plants the right kinds of fertilizer in the right quantities will directly impact the quality of the edibles they yield.
Gerber says that the most important thing to remember about container gardening is that this “small bit of garden” depends entirely on you. A pot-bound plant has no other consistent sources of water, nor can it seek out nutrition from surrounding soil like its in-ground kin. As its caregiver, you are the sole source of everything it needs to thrive.
Containers are generally made of four different kinds of materials. Each type has benefits and drawbacks.
Wood • Long-lasting, but can also be susceptible to rot or may have been treated with poisons that can leach into your soil (and end up in your food).
Metal • These also last for years, but if they’re too small, they can heat up and cook the delicate roots of your plants, and the wrong kinds of metal can rust.
Plastic • Easy on the pocketbook and non-porous, which may lessen how frequently you need to water. But plastic containers (especially if they aren’t UV resistant) can become rigid and crack, shortening their livespan.
Pottery • These containers are either very porous (unglazed terra cotta) or less porous (glazed ceramic) and can be beautiful, but they can also be fragile and quite expensive.
Other things to consider
Soil in unglazed pottery will dry out rapidly in the hot summer sun, making a twice-a-day (or more often) watering schedule a very realistic possibility.
Ceramic pots glazed in dark colors may also become too hot for the plants they hold.
If you’re away from home a lot during the summer, you may want to choose containers that retain moisture well and set up an automated timer to water while you’re gone.
If you plan to leave your pots outdoors during the winter, they’ll need to be weather resistant.
What • “How to Grow Plants in Containers”
When • Saturday, April 28, 10 am.
Where • Conservation Garden Park, 8275 S. 1300 West, West Jordan