Growing Edibles in Containers

Growing an edible garden makes great sense – you use water to produce food, and it’s food that can’t get any fresher or more local! Growing food in pots and other containers can be even more rewarding, especially for gardeners who have limited space, problems with critters or who want their herbs and vegetables close at hand.

lettuce and tomatillo plants in containers
Lettuce is a great container plant. The one in the foreground had tomatillos, just for fun, not so much for yield.

Rosemary, basil, lettuce and cherry or grape tomatoes are my favorite edibles to have right near my kitchen door. But I’ve been known to push the boundaries a little, once growing an okra plant in a small container (admittedly mostly for the flower) and a large pot of carrots last year. We’re upping the ante with an even bigger carrot crop, but more on that in a future post…

carrots
Here’s our dancing carrot, or rather two carrots, grown in crowded container conditions last year.

Here’s the thing – containers can take a little more water during hot summer months, but you also can confine your crop, so to speak. I believe that container-grown edibles are less susceptible to some bugs and soil-borne problems. And I love that I can move the containers to control sun exposure as the conditions change. Most of all, you just can’t beat the convenience of herbs and vegetables just outside your kitchen door at meal times.

Here are a few tips for making your container edibles fun and productive:

  • First, it can be tempting to fill your containers with soil from your garden. Resist the temptation and spend the money on some good commercial potting mix. I use organic composts and potting mixes. The reason? Ground soil compacts when confined to a pot. This makes it harder for water to drain and for roots to grow.
  • Choose your container to fit the plant’s mature size. It might look less attractive at first, but the reward of juicy tomatoes is worth your patience!
grape tomato in container
This yellow grape tomato was great for snacking right on the patio all summer.
  • If the container is particularly large, you can line the bottom with pebbles or plastic bottles to encourage drainage and use some yard or garden soil for fill. But keep it to a minimum, and make sure the soil that the plant’s roots touch is the best possible mix.
  • A few herbs are grown better in containers for their own special reasons. I like to have a small basil or rosemary on my patio table throughout the summer for the appearance, scent and convenience. And then there is mint – which should only grow in containers unless you really love it and want to replace everything else in your lawn, your neighbor’s lawn, your town… with mint. And it comes in lemon, orange or chocolate varieties to enjoy on the patio or balcony.
  • Many container-grown plants require fertilizer because the soil doesn’t have the same natural nutrients as garden soil. But use it judiciously and according to the individual plant. For example, chile peppers typically need no fertilizer. If you start with healthy soil, you need less, and if you use it too often or at the wrong time, you’ll force more growth into the foliage and get a plant that outgrows your container and gets too lanky to support its fruit.
  • Usually, you have to water container-grown plants more often, but not always. Don’t assume that when a plant wilts, lack of water is the cause. And that’s the beauty of containers – try moving the plant to the shade on hot days, or move all of them there if you have to be away for the weekend. They’ll survive better on your pre-departure watering until you return.
  • Remember that you can add mulch to containers, just as you do in flower beds. Decorative mulch can offset the look of an edible in a container, such as crushed seashells under chard. Mulch also serves a practical purpose. Those white seashells or pebbles can reflect sun back up to your potted lavender or bark chips can hold moisture in to conserve water and keep plants cool.

And if you love being creative and repurposing, go ahead and push the limits. You might end up with lower productivity from your edible, or need more total containers, but it’s fun to place edibles in a few fun or funky containers. If I want more yield, I duplicate the seeds or transplant in the ground or a larger container. That way, I get the aesthetic pleasure and practical returns.

spinach in metal container
We found this old metal bucket at my in-laws’ ranch and planted some spinach in it.

Favorite Low-water Container Herb: Rosemary

I love rosemary in a container for several reasons. First, I can keep it in a sunny location all year and leave it relatively close to my kitchen to snip stems for cooking. I don’t have to traipse out to the garden to get to it quickly. By leaving the pot close to a south-facing wall in winter, the plant, which is hardy to zones 6 through 8, receives some extra warmth.

rosemary-in-container
Established rosemary in pot that wintered over. I took a few cuttings, but it still has outgrown this narrow container and needs transplanting.

Cutting some rosemary stems for culinary use helps keep the plant compact enough for container living. Otherwise, it might begin to flower and outgrow the pot. When rosemary blooms, it’s an attractive, evergreen Mediterranean plant, and bees love the tiny bluish-lavender flowers. So I usually have at least one rosemary in the landscape, and one or two in containers purely for edible reasons.

Easy-Care Herb

Rosemary is best grown from a nursery transplant or cutting, not from seed. When preparing your container, be sure it has a hole for drainage and mix well-draining soil that’s slightly alkaline and not too fertile. You won’t need to fertilize your rosemary, either, but adding an organic fertilizer when transplanting or once a season shouldn’t harm the plant. Just keep it as warm as you can in winter if you live on the cooler side of the zones, and if you bring the container inside, place it in a sunny location.

rosemary in container
New rosemary plant in a container, ready to head outside for full sun exposure.

Rosemary is drought tolerant and one of the few problems you’ll encounter with rosemary is caused by wet roots when temperatures drop. Rosemary thrives in full sun, and in summer, container plants need some supplemental watering every few days in the heat. Transplant the rosemary to a new container when the plant becomes too large.

Benefits of Rosemary

The aromatic and flavorful leaves of rosemary have many uses. I love the scent of rosemary and lavender in those rice-filled neck warmers! The oil from rosemary leaves is said to help with heartburn and other digestive problems. The oil may also help soothe skin irritated by eczema. Of course, it’s widely used in perfumes, sachets and lotions.

rosemary stems and leaves
The only thing better than looking at a rosemary plant is running your finger over the stems, or cutting some for use in your kitchen!

Culinary Uses

Although rosemary smells great in patio containers and in the home, I love it even more with chicken. You can cut entire stems of fresh rosemary and place them inside a baking chicken or use them in kebobs along with chicken or steak. I love fresh or dried rosemary on potatoes, baked with olive oil, minced garlic and sea salt.

It doesn’t take much rosemary to achieve a lot of flavor, and I haven’t met anyone yet who dislikes the scent or taste of the herb. I often have add rosemary to garlic bread. That’s an easy way to get a little of the flavor of focaccia bread without having to bake!

Harden Off Seedlings Before Planting

When you head out to your garden on a chilly morning, it takes you some time to acclimate to the weather. After you’ve done some digging or weeding for 15 minutes or so, you might peel off a layer of clothing as your body warms up. The outside temperature probably didn’t change much in 15 minutes, but your body adapted to your surroundings and even toughened up to take them as your blood pumped into muscles and your heart rate rose.

tomato seedling
Short-season tomato seedling growing in starter soil.

Your tomato and other vegetable and herb seedlings need the same sort of acclimation before you take them from under your grow light, from a greenhouse, or from the comfort of their commercial nursery home. Give them a little bit of time to adapt to their new outside location. It’s called “hardening off,” and here are a few tips:

  • Take a minimum of a few days when you can, and ideally up to a week, to harden off seedlings. Count backward from your planting date – usually your average last day of frost – and start hardening off seedlings about eight days before that date.
  • Ease your plants into their new environment. That means it’s not a good idea to take them from a greenhouse from dawn to dusk the first day. Start with a few hours of outdoor time and gradually increase it each day. Cut the time short if the wind really picks up.
  • Speaking of wind – and sun – keep your plants in a fairly protected location. Start by putting them out mostly shade the first day and moving them every few days to gradually increase their sun exposure. You may need to protect them from critters, too, so consider local bunnies or other munchers if they often visit the area where you set out the seedlings and place them up on a table.
Seedlings and cuttings hardening off
Tomato seedlings and sage cutting hardening off under the shade of a glass patio table. The table offers some shade and wind protection.
  • Gradually increase time spent out late in the day as well. Your plants need to learn to spend the night outside, but don’t leave them out the first few nights. And be sure to bring them inside if there is any chance of freeze. On the first night out, try to put them in a well-protected location where they won’t get too much wind and receive a little warmth from your home or a south-facing wall.

Finally, cut back on watering as you begin hardening off the plants. They also need to learn to toughen up before transplanting. Of course, once you plant them, water a little extra until established, then water consistently per the plant’s needs.

bell pepper seedling
Bell pepper seedlings need to harden off and toughen up before the soil and daytime temperatures are hot enough for us to plant them.

Low-water Herbs for Your Garden or Kitchen

Planning your spring garden or patio plants? You might have limited space, and certainly should consider limiting water use, so I’ve got a few tips for choosing low-water herbs for your garden, kitchen window or patio.

The good news is that like many xeric plants we grow in New Mexico gardens, many herbs have their roots in the Mediterranean. They prefer well-draining soil and low water.

Rosemary (Rosemarinus officinalis) is the first herb that comes to mind, and is one of my favorites, both as an herb and as an ornamental. You can grow a small rosemary in a pot, keeping it trimmed (by cutting the tips and using the herb in recipes, of course) or grow a mounding or spreading form of the plant in your low-water garden. As an ornamental, rosemary has attractive foliage and blooms with light blue or pink flowers. It’s a tough herb that survives cold to about 15 degrees Fahrenheit. Just watch for overwatering and snow damage. If you get a heavy snow, try to knock the powder off your rosemary plant. Here’s a link to the Herb Society of America’s fact sheet on rosemary.

rosemary-in-container
Established rosemary in pot that wintered over. I took a few cuttings all winter.

Thyme (Thymus) is another low-water favorite. Thymus vulgaris is the common shrubby herb, but several ornamental forms provide interest in the garden, and other flavors provide culinary variety. For example, lemon thyme is a favorite for marinades or sauces. I love to walk around our rock garden and rub my fingers on the leaves of our thyme shrub just to get a whiff of the scent, which is sort of a combination of earthy and salty. We use the dried leaves in several recipes and also enjoy the tiny, delicate lilac-colored flowers in summer. Thyme only needs water in the hottest zones and times of year.

thyme--herb-low-water
Thyme is evergreen even in Zone 6. Some of it dies back, and new growth appears on new stems. This is new growth in early March.

 

Lavender (Lavendula) is a favorite Mediterranean herb, and we are experimenting now with several varieties. Our biggest mistake was to place the mail-ordered plants in the ground a bit early. The soil was not warm enough for the sun lovers. Lavender must have well-drained soil to prevent the roots from sitting in water. In New Mexico, French of Spanish lavender works much better than English lavender varieties. Be careful not to cut into the woody stems when trimming. Check with nurseries or catalogs for the best variety in your area and zone and for the purpose you want. I’ve used lavender in recipes, and have dried stalks of it in vases throughout my home just for scent and attractiveness. We’ll keep trying to improve our lavender-growing skills, and studying ideas for uses. Check out our Pinterest board for more on lavender.

lavender-in-container
A new lavender plant in a container.

Fennel (Foeniculum vulgare) needs full sun and most varieties require no watering. Although not as attractive as the other plants I’ve mentioned, fennel is a versatile herb and easy to grow. We haven’t planted any, but it’s popped up around our garden, presumably from seeds of past plants. The fern-like leaves do have some appeal, and birds love the seeds once they turn brown. With a flavor similar to anise, fennel is a stock herb for many breads and pickling mixes. Learn more from the Herb Society of America.