How to Grow Vegetables in Pots and Containers - Tips, Guides, Facts

Growing vegetables in containers can be a good idea even if you have an outdoor garden as they are easier to plant and look after. Containers allow you to have a mobile garden, its easier to control pests and they can be very attractive. For people who live in units, flats and apartments growing in containers is the only way to produce homegrown and organic vegetables and fresh herbs. Growing vegetables in containers is a wonderful great to teach children about gardening. This article will help you get started with lots of practical tips guides and facts for growing vegetables in pots and containers.

The major problem with container gardening is watering. You need to maintain routine and regular watering because the containers dry out quickly, but there is little waste and you can use simple soil moisture meters to tell you when to water.

Tips for Growing Vegetables in Pots and Containers

You also need to do some research as many vegetables simply don't grow well in containers and you may need to source dwarf or bush varieties that are more suitable for pots.

The primary vegetables that do well in containers are those with ore compact forms such as salad greens, radish, carrots, spinach, eggplant, Swiss chard, beets, peppers, bush beans, cherry and standard tomatoes, bush forma of summer squash and cucumbers, green onions, and many herbs. Look for dwarf and bushy forms that are more compact. Don't forget growing climbing varieties of beans and pea on poles or frames. Climbing varieties do very well in pots, supported by frames or stakes.

Growing vegetables in containers and pots has the following advantages and disadvantages.

Advantages

Disadvantages and Potential Problems

Choosing the Containers

Any good sized container is suitable for growing vegetables, but the larger size that can fit your space the better, except for small plants such as herbs. Remember that larger pots can be very heavy to move, and always move them when dry as the water may double the total weight . Wooden barrels, old buckets, pots, drums and tubs, and many commercial varieties of all shapes and sizes are suitable provided drainage can be provided. To encourage good drainage, put a minimum 1 inch (3cm) deep layer of small stones, coarse gravel, or pieces of broken pot in the bottom of the container. These items stop the drainage holes being blocked. A saucer beneath each pot is a good idea for tidiness and to capture the excess water and store it so that it can be used by the plant

Most vegetables need containers that can hold 6 to 8 inches (10-15 cm) of good quality potting mix. See the tables for the soil capacity of various size pots and suggestions for the size of pot needed for various vegetable species

The appearance of the pots may also be very important in locations such as balconies. Certain types of pots offer special advantages. Pots with angled sides will generally stay cooler than vertical sided one. Plastics pots heat more quickly but retain heat for shorter periods. Terracotta, ceramic, concrete stay cooler and retain water. © janderson99-HubPages

The capacity of various pots is shown in the Table below.

Diameter inside top (inches)
(cm)
Approximate soil content
(liters)
3
8
1 cup
0.2
4
10
2 cups
0.4
5
13
1 quart
1.0
6
15
2.5 quarts
2.5
7
18
3 quarts
3.0
8
20
1 gallon
3.8
9
23
1.5 gallons
5.7
10
25
2.25 gallons
8.5
12
30
3.5 gallons
13.2
14
36
6 gallons
22.7

Soil and other Growing Media

A suitable potting mix needs to supply the plant with support, nutrients, water, and should be lightweight, well-aerated, well-drained. Do not use mixtures with anything like 100% garden soil, which is far too heavy, dense, and will compact and not drain adequately. It will also dry out quickly, and may be far too acid or too alkaline. Garden soil may contain diseases such as fungal pathogens and bacteria, weed seeds, pests and many disease organisms. Peat-based mixes using 30-50% soil combined with peat, compost and vermiculite, are generally the best. 
There are many commercial pot media that can be used for growing vegetables. These are convenient because they come in bags ready for easy transport. For convenience choose one that contains nutrients and wetting agents so that your plants can be grown immediately in your mix. Commercial mixtures are relatively sterile and pH adjusted and are very convenient.
Use slow release pellets or other complete organic fertilizer at planting. You can supplement this with liquid fertilisers applied periodically are needed to keep your vegetables growing until harvest.

Soilless mixes - are made up of vermiculite, peat moss and generally coarse sand, bark or wood products. Vermiculite retains many times its weight in water and nutrients, and helps keeps the soil in the container moist between waterings. The soilless mixes are light in weight and preferred if the container is to be moved regularly. Soilless mixes are generally preferred by most people, although they can be expensive. They are guaranteed free of various plant diseases, pests and weed seeds, are less prone to compact. Soilless mixes hold moisture and plant nutrients well. You can make your own soilless mixture using the recipe shown below.

Soil-less potting mix recipe
 
 
Materials to make 2 bushels (70 litres)
Quantity (Imperial)
(metric)
Shredded sphagnum peat moss
1 bushel
35 litres
Vermiculite
1 bushel
35 litres
Ground limestone
1.5 cups
345 ml
Superphosphate (0-20-0)
0.5 cup
115 ml
or Superphosphate (0-45-0)
0.25 cup
58 ml
Granular 5-10-5 fertilizer
1 cup
230 ml
Moisten with water; store in plastic garbage bags.
 
 

Watering - Plants grown in pots and containers, particularly in exposed locations require frequent watering because the soil in pots and containers dry out quickly. Some plants may even need to be watered every day. Apply enough water to ensure it drains and waters all the soil in the container and leaks out into the saucer. Don't allow the soil to dry out completely between waterings as this may kill the plants or slow plant growth. However, over­watering can slowly kill the plants because the roots will not receive enough oxygen. You can buy inexpensive water meters that are a good way to tell you when you need to water the plants. When watering, try to avoid wetting the leaves, especially when watering late in the day as water on the leaves can lead to plant diseases. 

Fertilization - Plants grown in containers require nutrients to be topped-up more frequently than garden grown vegetables because they have less soil. A soluble fertilizer (N-P-K = 15-30-15 or 20-20-20) should be applied once a week or once a fortnight. Fertilises can be applied to liquids when watering. 

Best Crops for Containers

List of Vegetable plant varieties suitable for container gardening

Carrots

Generally most varieties of carrots require a long growing season and growing them in containers can be a tedious a drawn-out process. However they are two ways to make it work:
1) Seed a few carrots in with a pot of flowers. The ferny carrot foliage is attractive as an under-storey and you will be harvesting the young baby carrots before the flowers have finished their run.
2) Choose modern fast growing round or baby carrot varieties, like 'Paris market' or 'Babette'.

Green Onions

Full sized onions harvested as mature bulks are not generally suited to pots as they take too long to grow. However, green or bunching onions can be added to pots or containers with other vegetables or grown on their own with your herb garden pot array. Look for the following varieties: 'Crystal Wax', 'Beltsville Bunching' and 'Evergreen Bunching'.

Eggplants

Growing eggplants in large containers helps to control some common pest that ruin crops in open garden beds. Eggplants bushes can get very heavy with fruits and some staking or support may be required. The slender varieties, like 'Ping Tung', 'Bambino' and 'Slim Jim' are good choices. Aim for fast growing compact varieties.

Green Beans

Pole beans are a great choice for containers because they grow up rather than spreading out. You can continuously harvest the beans as they are produced. They require support in the pot or container. The best general purpose varieties are: 'Kentucky Wonder', 'Lazy Housewife', 'Blue Lake' and 'French Dwarf. Bush beasn also work well in large containers and can be paired with tomatoes.

Cucumbers

Cucumber varieties that grow in a compact clump, rather than long, sprawling vines are suitable for large pots or containers. Even these bush varieties can still spread out. Try compact varieties such as: 'Salad Bush Hybrid', 'Bush Pickle', 'Spacemaster'.

Beets

Generally suitable

Asian Vegetables

Generally suitable

Cabbage

Needs large pots and dwarf varieties

Leaf lettuce

Very suitable and can be continuously harvested.

Herbs such as Coriander, Parsley and Basil

Very suitable and can be continuously harvested.

Peppers - Sweet and Hot

Very suitable and can be continuously harvested.

Radishes

Very suitable and can be continuously harvested. Thin to avoid overcrowding.

Spinach - Tall and Baby Varieties

Very suitable and can be continuously harvested. Thin to avoid overcrowding.

Swiss Chard

Very suitable and can be continuously harvested.

Tomatoes Cherry

Very suitable and can be continuously harvested.

Tomatoes Standard

Need support such as stakes and frames, or support up walls.

Snap and Sugar Peas, Climbing Peas

Climbing peas need support such as stakes and frames, or support up walls. Bushy snap and sugar peas are a fabulous vegetable for large pots and containers.

Climbing Beans

Very suitable and can be continuously harvested. Needs support

Size of Containers for Various Plants

Crop
Minimum Size (gallon)
(litres)
No. of plants per container
Beets
2 gallon
7.6
Thinned to 2-3 inches apart
Cabbage
1 gallon
3.8
1 plant
Carrots
2 gallon
7.6
Thinned to 2-3 inches apart
Cucumber
1 gallon
3.8
2 plants
Eggplant
2 gallon
7.6
1 plant
Green beans
1 gallon
3.8
2-3 plants
Leaf lettuce
1 gallon
3.8
4-6 plants
Parsley
1 gallon
3.8
1 plant
Pepper
2 gallon
7.6
2 plants
Radishes
2 gallon
7.6
Thinned to 1-2 inches apart
Spinach
1 gallon
3.8
Thinned to 3 inches apart
Swiss chard
1 gallon
3.8
1 plant
Tomatoes Cherry
1 gallon
3.8
1 plant
Tomatoes Standard
3 gallon
11.3
1 plant




Discover how to grow these fresh herbs and vegetables in pots and containers.
Discover how to grow these fresh herbs and vegetables in pots and containers. Source: Public Domain
Homegrown tomatoes, fully ripened on the vine, have a unique flavor that cannot be duplicated with commercial varieties bought in the shops. Growing your own is very rewarding and easy if you follow the tips provided.
Homegrown tomatoes, fully ripened on the vine, have a unique flavor that cannot be duplicated with commercial varieties bought in the shops. Growing your own is very rewarding and easy if you follow the tips provided.
Pots and conatiners are suitable for a wide range of herbs and vegetables than can be mixed with flowers
Pots and conatiners are suitable for a wide range of herbs and vegetables than can be mixed with flowers. Source: Public Domain
Most vegetables grown in pots need support in the form of stakes and frames
Most vegetables grown in pots need support in the form of stakes and frames. Source: Public Domain
Tomatoes are great grown in pots. They need support from stakes and frames
Tomatoes are great grown in pots. They need support from stakes and frames. Source: Public Domain
Flat leaf parsley is amongst the most nutritious of all fresh herbs. most of which can be grown well in pots and containers
Flat leaf parsley is amongst the most nutritious of all fresh herbs. most of which can be grown well in pots and containers. Source: Public Domain
Providing a mini-hot house for your tomatoes in pots increases growth rates and prevents the plants from drying out. This increases yields and harvest reliability
Providing a mini-hot house for your tomatoes in pots increases growth rates and prevents the plants from drying out. This increases yields and harvest reliability. Source: Public Domain
Beans grow very well in pots and can be continuously harvested
Beans grow very well in pots and can be continuously harvested. Source: Public Domain
Snap and Sugar Peas are a fabulous vegetable for large pots and containers
Snap and Sugar Peas are a fabulous vegetable for large pots and containers. Source: Public Domain
Peppers and chillies grow well in pots and containers
Peppers and chillies grow well in pots and containers. Source: Public Domain