If you don’t have space or adequate sunlight to grow your vegetables in the ground, containers are the next best option. You can grow edibles in large pots, self-watering boxes, and fabric containers such as Smart Pots, placing them on decks, patios or the edges of driveways as needed. That said, there are several key tips and practices that will lead to success and tasty harvests.

• Use large containers and don’t be tempted to grow too many plants per container. More about specific vegetables later, but just remember that will all plants, the root growth that goes on in the soil will determine how big the plant gets and how much food it will produce. What goes on below is reflected up above.  In other words, crowded roots will result in smaller plants and fewer vegetables.
• Fill the entire container with soil. No rocks, shards, mulch or other debris in the pot. Make sure each container has a drainage hole. If you’re growing in large buckets, drill three or four drainage holes per bucket before you add the soil. Use new potting mix every year unless you have huge containers, in which case you can remove half of the soil from the previous year in the spring, loosen the remaining mix well, and add new potting media on the top.  Since potting soil is mostly organic matter, it breaks down in containers which means poor drainage and less root growth.
• If you are growing in large Smart Pots, you can fill them with a mix of loam and potting mix, or garden soil and potting mix. Either a 50/50 blend, or up to 75% loam/soil and 25% potting media or compost.
• Place containers onto “pot feet” if desired so that the excess water runs out but doesn’t rot a deck underneath. Smart Pots can be placed on wood platforms or large plastic saucers turned upside down and elevated as well, so that the moist underside doesn’t mark your patio or deck. Saucers can accumulate standing water where mosquitoes will breed, and should be avoided outdoors.
• Space containers so that there is room for all the plants to grow wide and get adequate sunlight. You want at least 5 or 6 hours of direct sun including the noon hour whenever possible.
• The larger the plants, the fewer you should include in the container. So if you’re growing tomatoes, broccoli or Tuscan kale, plant one per pot. Medium size plants such as eggplants and most peppers could grow two plants in a 20″ diameter pot. Small plants such as lettuce or arugula can be broadcast over the surface of the soil so several plants will grow per container. Use spacing guides for plants and seeds that you read on the tags and seed packets.  Good vegetables for a long harvest from containers are listed below.

This gardener grew tomatoes on a bulkhead. Note that there is one tomato plant per pot.

There are several types of miniature or “salad” tomato plants, but in general, the smaller the plants the fewer tomatoes you’ll harvest. 

I have grown eggplant, peppers, leeks, potatoes and salad in Smart Pots very successfully. This photo was taken on taken in a root-top garden in Quebec City, where all sorts of vegetables were being grown. Note that they have set up an automatic watering system for these pots.

Best Vegetables to Grow In Containers:  Zucchini, green beans, Tuscan kale, chard, lettuce, arugula, and tomatoes will produce the most produce for the space allowed. Pick the beans and zucchini every other day, and harvest the largest, oldest leaves off of the lettuce, kale, chard and arugula to keep them growing most of the summer. Many vegetables will continue to produce when they are picked regularly.

Potatoes grow most successfully in a 15 gallon Smart Pot, and you can plant six seed potato pieces per pot, three on a bottom layer and three in the middle, all covered by at least six inches of soil. Peas are only worth growing in containers for children; you won’t get many per plant, and the harvest period is pretty short. The yield for eggplants and peppers is okay but again, not as numerous or constant as the other vegetables listed.

Sweet Heat is a variety of pepper that does well in containers. The peppers range from sweet to mildly spicy, and the plants don’t grow tall.

• Watering Tip for Success:  Water your containers well in the morning. Use a watering wand, such as the Rainwand from Dramm. After watering them throughly once, go back and water them again.  On very hot days, or days when it’s both sunny and windy, check the soil in the late afternoon and see if it’s dry. If so, water in the evening as well.  Keeping the soil evenly moist is the key to avoiding problems such as blossom end rot and cat-facing in tomatoes.

Livestock troughs are good for growing vegetables in that they are large and deep, plus attractive! They already have a drainage hole in the bottom. You can either fill them with soil as is, or line them with very large Smart Pots. If you want to grow carrots, these would be the containers of choice. A trough this size could grow a tomato plant in the center, a zucchini (or green beans but not both) on one end, and some chard and basil on the other end. You could even sneak some parsley and lettuce plants along the edges in front and back of the tomato.

Herbs are easy to grow in containers. Here, the pots hold herbs and the trough has assorted edible greens and flowers.