Hello,

Both Peppers and Tomatoes have different needs for growing in containers.  Refer to https://extension.colostate.edu/resource/vegetable-gardening-in-containers/ for references to how large of a grow bag you need.  Pay attention to the minimum depth required and ensure your grow bag meets both depth and capacity size.  For a tomato plant consider 5 gallon bag as the smallest size. You will have one plant per bag.

I am including two short articles about grow bags and their use.

https://ucanr.edu/site/uc-marin-master-gardeners/article/february-2023-growing-veggies-bags

https://franklin.mgcafe.uky.edu/sites/franklin.ca.uky.edu/files/Gardening%20in%20a%20grow%20bag%20edit%202.pdf

For the soil, you will want a potting soil that is lightweight. Common ingredients include peat moss and/or ground bark to hold water and nutrients, vermiculite for water retention, and perlite to loosen the mix and allow for air movement.  Most commercial potting mixes will contain these ingredients.

You can use this online calculator to help you figure out soil quantity https://plantcalculators.com/indoor/potting-soil/  Most potting soil bags will indicate how many cubic feet of soil you are purchasing.

Happy Gardening

Jeffco Master Gardener Brenda