Grow bags are plastic bags filled with a nutritious growing medium such as peat. They're an alternative to using pots or planting in the ground and have enough nutrients to supply your plant for a year. All you need to do is plant whatever you want to and water. Quick and convenient.
Growbags as I'm speaking about here are different from the thick plastic containers that nurseries use. Growbags are fully enclosed rectangular bags that need to be pierced to access the soil.
The standard growbag size is 35cm x 95 cm (13in x 37in) although other sizes are available. The standard size can hold around three vegetable plants quite comfortably.
Because growbags come ready with nutrients in the growing medium, they are often tailored to specific crops.
Growbags are not very deep and are therefore best suited to plants that have fairly shallow roots. Salads, herbs and veggies are good choices as are strawberries.
Because growbags have their own compost and nutrients, most of the caring you'll have to do is to water your plants. Water your plants as normal. That's not to say that you want need fertilizer at all. The nutrients in the growbag may not be ideal for what you're planting and you may want to top up with a fertilizer that's more suitable.
I read about a good suggestion to make watering a bit easier. Use little plastic pots as funnels into the growbag. To do this, cut another X for each funnel pot and place an empty pot in the hole. Then to water, just pour water into the pot and the water will flow to the roots of your plant.