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| Photo: Mary Meyer, UMN Extension |
What's the right size?
Tomatoes like 'em big! Use at least a 12" diameter pot, but overall larger is better. Larger pots provide more soil and hold more water which minimizes wilting and stress as plants get large. See the table below that matches plant type to container size.What's your container made out of?
Avoid using metal containers, which can absorb too much heat and be deadly to plant roots. Roots cannot tolerate extreme high or low temperatures that upper plant parts can take. Black containers can also be very hot for roots in full sun conditions. Light colored containers are best at minimizing hot conditions.Soil & Fertilizer
Lightweight potting soil is good for container vegetables and herbs. Adding slow release fertilizer with the potting soil is a good idea. Read the label on the soil mix to see if fertilizer is included. Applying liquid fertilizer weekly is a good rule of thumb.Very large containers can be filled on the bottom 1/3 or ¼ with crushed milk jugs to minimize using large amounts of soil, if necessary.
Watering & Maintenance
Container vegetables and herbs need to be located in full sun and will need watering daily as the plants grow and begin to produce. Watering in the middle of the day can cool the containers and roots. All containers should have good drainage--no water should stand around plant roots.A handy size chart
The chart below shows container sizes for popular vegetables and herbs. You can experiment with your own variation, but remember bigger is better when growing vegetables in containers.
Table1. Vegetables and herb with
container size and comments.
|
Plant
|
Minimum Size
|
Preferred Size
|
Number of Plants
|
Comments
|
|
Basil
|
1 gallon; 6-7 inch diameter
|
2 gallon; 8-9 inch diameter
|
3-4
|
Mildew resistant: Prospera®
or Amazel TM harvest and water
regularly
|
|
Parsley
|
1 gallon; 6-7 inch diameter
|
2 gallon; 8-9 inch diameter
|
2-4
|
Flat or curly leaf; harvest and
water regularly
|
|
Leaf lettuce; spinach
|
1 gallon; 6-7 inch diameter
|
2 gallon; 8-9 inch diameter
|
3-4
|
Prefers cool weather; harvest and
water regularly
|
|
Green beans
|
2 gallon; 8-9 inch diameter
|
5 gallon; 12 inch diameter
|
2-4 plants; space 3 inches apart
|
Bush Blue Lake; Provider or other
bush bean
|
|
Rosemary
|
1 gallon; 6-7 inch diameter
|
2 gallon; 8-9 inch diameter
|
1
|
Shady Acres
|
|
Peppers
|
2 gallon; 8-9 inch diameter
|
5 gallon; 12 inch diameter
|
1-2
|
Ace, New Ace; Lady Bell
|
|
Determinate tomato
|
5 gallon; 12 inch diameter
|
10-15 gallon; 16-18 inch diameter
|
1
|
Patio, Bush Early Girl; Celebrity
|
|
Indeterminate
tomato |
5 gallon; 12 inch diameter
|
10-15 gallon; 16-18 inch diameter
|
1
|
Sweet 100; Super Sweet 100;
Sungold; Early Girl
|
|
Kale
|
2 gallon; 8-9 inch diameter
|
5 gallon; 12 inch diameter
|
1-2
|
Winterbor; cold tolerant
|
Other resources
Minnesota Master Gardener recommended varieties: https://extension.umn.edu/planting-and-growing-guides/master-gardener-seed-trials
Karl Foord, former Extension Horticulturist, "How-to" video on container or vertical gardening on a deck or patio:
Cornell recommended vegetable varieties:
Author: Mary H. Meyer, Extension Horticulturist & Professor
