Avoid Poor Harvest in Edible Container Gardens

Growing anything in a container is a little different than growing in your garden, and you can grow just about anything in a container as long as the pot is big enough. If you have a small property or just want your edibles outside the kitchen door, growing in containers is a big advantage. It is easy to make some mistakes learning to grow vegetables in containers, but there are a few basic lessons to avoid poor harvests from edible container gardens.

SELECTING A CONTAINER

You can use just about anything for your container that will hold soil, just remember that bigger is better. It will allow for more extensive root development for your edibles, as well as retain moisture better simply because there is more soil to hold it. But also consider the weight of a filled container and whether you need to flexibility of moving it out of midsummer heat or early and late season frosts.

Before you ever fill your container with soil, make sure it has drainage holes, ideally 4 or more. You can drill in your own holes if necessary. Do NOT use rocks or gravel at the bottom as drainage, it only takes up valuable soil space for roots. But you may want to use fine mesh screens over the holes to reduce soil running out with the excess water.

WATER

Moisture of course is critical to successful growing, but in containers you need to really pay close attention. Over watering can be even more detrimental than under watering. So in addition to paying close attention to whether the soil is dry, you need to take the necessary steps to help retain moisture but also make sure that excess water can drain.

SOIL

Never, ever, use garden soil. It will not properly retain moisture and drain the way it will need to in a container. Use only soil blended specifically for containers. It can be bagged potting soil or your own custom potting soil full of nutrition and minerals that will ensure a great harvest. A good potting soil will hold moisture well, but try to avoid chemical laden water saving crystals. You may want to try a prepared organic potting soil blended for edibles.

PLACEMENT AND EXPOSURE

Make sure you position your edible containers to get appropriate sun for the plants you select, most edibles prefer at least 6 hours of direct sunlight. There are of course some exceptions, certain crops will do fine if not prefer some shade in the heat of the day. Manageable sized containers can also be moved out of the sun during unusual heat. And don’t hesitate to plant closely, a pot with full foliage will shade the soil and keep plant roots cooler and help retain moisture. Do, of course, be careful not to overcrowd the plants. They will not have adequate room for root development and will compete for moisture, nutrients and sunlight. It might take a little experimenting to learn how many and which plants to combine in your containers. And don’t forget to consider convenient placement to water your containers. They will need closer attention for moisture than your gardens.

NUTRITION

If you want amazing flavor and good production from your container edibles, proper nutrition is essential. As noted above that should start with a potting soil that includes minerals and nutrients. But as your plants grow they will need continued supplemental feedings. Use a liquid fertilizer and follow the package directions. You may prefer to use organic fertilizers rather than synthetic for edibles. Also look for fertilizers specifically blended for certain crops. For example tomatoes prefer plenty of potassium and they do feed heavily. Most edibles will do fine with a general purpose balanced fertilizer.

SELECTING PLANTS

For containers smaller varieties of edible plants should be selected. Look for dwarf and container plants. Also consider using a trellis in larger containers or in trough planters to grow vertically. Peas and beans will grow easily in containers. Container gardens are also perfect for seasonal edibles. You can easily rotate spring, summer and fall crops. Herbs of course are also ideal for containers and can be easily placed right outside the kitchen door for quick access when cooking. Some fruits do well in containers, in particular strawberries. And why not a few edible flowers for salads or beverage garnish?

PLANTING GUIDES

I have grown many edibles in containers successfully so don’t be afraid to try your personal choices. Some basic guidelines of how much container space plants will need should help you get started.

• A tomato plant likes deep roots, plan on one plant in a container about the size of a grocery bag. Dwarf tomato plants and patio tomatoes will not need quite so much room, but still use at least 12 inches deep. Indeterminate varieties will of course need a plant support, and even larger bush varieties will hold together better with a cage.

• Greens including spinach and chard will grow well in a relatively shallow pot or trough planter about 8” deep. Within the length and width of your planter space the plants about 4 to 6 inches apart. Collard greens might like a bit deeper soil, up to 12 inches.

• Squash should be grown in a deep pot, about 24”. A 2 gallon pot will accommodate one squash plant, with 4 gallons you can use 2 or 3 plants.

• Beans and Peas that vine will need a trellis. Trough planters 10 or 12 inches deep work well. Plant 2 to 3 inches apart.

• Cucumbers will need a support and 4 to 5 gallon containers. Dwarf cucumbers remain more compact and will do nicely in smaller containers, 2 or 3 gallons.

• Pepper plants prefer a bit of room so only one plant per container of about 16”, roughly 2 or 3 gallons.

• Herbs can often grow well in small 6 inches pots for a single plant. Use a trough planter or larger pot for repeat seeding of cilantro or parsley. Rosemary and basil can get quite large so I do like to use a good size container of about 12 inches.

And don’t forget to tuck in some pretty little annuals wherever you have room!