Master Gardener Randy Schultz knows his tomatoes, and a whole lot more. Randy gave us professional advice for successfully growing plants in containers and raised bed gardens. Read his tips for cultivating your own green thumb, no matter what type of outdoor space you have available.
Tell us a little bit about your gardening background…
I first became interested in gardening by growing tomatoes in containers when I lived in a townhouse with no room for a traditional in-ground garden. The first vine-ripened tomato hooked me. I became a gardener for life. I have grown edibles every year since that first container tomato garden. Now I am also an avid ornamental gardener, growing flowering perennials and native plants that are in harmony with the local growing conditions. I am also in love with fruit trees.
I am still an avid tomato grower—plus other edibles including cucumbers, green beans, lettuce, spinach and squash. For many years I helped to produce the annual Albuquerque Tomato Fiesta—which attracts 1,000 attendees every August. Because of that, I have enjoyed growing and eating lots of exotic tomato varieties. I now grow all of my tomato plants only in containers.
I have been a Master Gardener for 16 years, and I am currently the Director of Product Development for NatureHills.com, an online nursery that offers a wide variety of trees, shrubs, and fruit-bearing and flowering plants.
What are the benefits of container gardening?
- Containers offer a controlled environment for growing, so it’s easier to give plants the growing conditions they prefer.
- Anyone can grow in containers—even if no space is available for a garden lot. You don’t even need any yard at all. A sunny front porch or balcony will do just fine. You can even grow a pot of kitchen herbs in a sunny window. Containers are great for apartment and condominium dwellers.
- Containers are great for beginning gardeners. A container is a smaller, less intimidating way to get started in gardening.
- Containers let you put your garden almost anywhere. People who love to cook can have a “kitchen garden” right outside their kitchen door where it is most convenient.
- Gardeners with problem soil (too much clay, sandy soil without enough nutrients) can use potting mix or compost-enriched soil in containers to create a great growing medium for plants.
What is the difference between container gardening and raised bed gardening?
Back when I started gardening, a “raised bed garden” was planted in the ground, but the soil level was raised by framing the area with wood. The taller the wood frame, the higher the soil level in the raised bed. This kind of a raised bed is a compromise between an in-ground garden and a container. Because of the popularity of raised bed gardens, now you can buy nice raised beds and raised bed kits so you don’t have to build your own raised beds. There are even elevated raised beds that raise the soil level up two or three feet off the ground. These elevated raised bed containers are great for elderly gardeners and disabled gardeners with limited mobility.
What type of soil and fertilizer do you recommend for raised beds or containers?
I use a high-quality bagged potting soil in my containers. The even consistency helps water travel through the potting soil to keep plant roots evenly moist.
Most potting mixes do not have sufficient nutrients for flowering plants, or fruit or vegetable plants. It is important to add plant nutrients throughout the growing season to keep container flower gardening plants healthy.
Use a well-balanced fertilizer to keep plants well fed. Follow the package instructions for the amount of fertilizer and the frequency of use.
What fruit-bearing trees can be successfully grown in containers?
I’ve had a lemon tree growing in a container in a sunroom window for years. It blooms every year and sets lemons that we can use in our summer beverages. You can grow all kinds of small citrus trees in containers including lemons, limes, kumquats and orange trees. Many gardeners bring the trees outside when the last chance of frost has passed, and they bring the trees indoors before the first frost in the fall.
I also love growing berry bushes in containers. Some of my favorites are Chester Thornless Blackberry, Jelly Bean Blueberry, and Heritage Raspberry.
Citrus trees are the most popular fruiting trees for containers. Among the most popular flowering trees for container growing are Red Knockout Rose (Tree Form) and Dwarf Korean Lilac (Tree Form). Flowering bushes work very well in containers. Among my favorites are cold-hardy azaleas like Bollywood and Pink Bloom-a-Thon.
What vegetables grow best in containers?
Tomatoes are America’s favorite homegrown garden crop—in the ground and also in container vegetable gardening. But almost any vegetable plant can be grown successfully in containers. Sweet peppers and hot peppers love growing in containers. Spinach, lettuce and salad greens grow very well in containers, especially early in the gardening season and toward the fall when the weather starts to cool off again. I have had tremendous success with different types of squash in my Grow Boxes. If they have some type of trellis or netting to grow up onto, pole beans and cucumbers are great container gardening plants.
I think everyone should grow an herb garden container in the kitchen. That’s the perfect container garden. Herbs are easy to grow, and it’s delightful to pick off a sprig of parsley or rosemary to add flavor to a meal.
How do you determine what size container a plant needs?
The size of the container needed is directly related to the depth and spread of a plant’s roots. So smaller plants such as herbs, lettuce, and spinach can be grown in a container that’s only six inches deep. Larger plants need larger spaces for their roots. Tomatoes, squashes, eggplants, and peppers should be grown in containers that are at least 12 inches deep. Small trees are happiest in even bigger containers.
The other thing about containers is that the larger the container, the less frequently they need to be watered. Some small containers placed in the full sun need to be watered more than once a day. That’s why I lean toward larger containers, because sometimes we’re all too busy to water more than once a day.
What features should I look for in containers?
I love self-watering containers for several reasons, and I use them almost exclusively for my vegetable gardening. I like the containers that have a water reservoir built into the bottom of the container. All you do is add water to the reservoir, and the potting soil in the container naturally wicks the water up to the plant roots.
What is the best way to keep container plants lush and healthy?
The key to growing healthy plants is to pay attention to their needs. Take a few moments every day to look them over and see how they are doing. It doesn’t take long to notice how a plant’s leaves start to look when it needs to be watered. Often leaves droop when they really need watering. But some plant leaves will start to look a little dull before they start to droop, and it’s better to water before plants show signs of severe water stress.
Check plants regularly for insect pests. Insects such as aphids can be sprayed off with a garden hose. (You may need to do this several days in a row to handle a serious infestation.) Some larger insects, such as tomato hornworms, can simply be plucked off and thrown into the trash.
Most people don’t know that insect pests and diseases tend to attack plants that are already stressed. So if you keep your plants healthy to begin with, you’ll have far fewer insect and disease problems. Happy growing!
Read More Patio Garden Ideas:
- Find great tips before you plant with our How to Prepare A Garden Planter guide.
- Short on space? See how one gardener created her own Small Backyard Garden Idea.
- Keep supplies within reach. Read our Potting Bench Buying Guide for shopping tips.
- Beautiful outdoor planters make a difference. Read our Garden Planter Buying Guide to find your faves.