So many elderly folk give up gardening as it becomes too much to cope with.
So the best thing you can do, is to show your group how easy it is to grow herbs in pots.
Mine are in a greenhouse, as our first planting, when we left the pots out in the garden, was demolished by squirrels - the fresh compost was too tempting for them to resist and they happily got digging...!
Herbs do well on windowsills too - just need plenty of light and moisture (careful of too much direct sun and keep damp but don't over-water)
Herbs are fast growing and there are so many available in seed packets. We chose Coriander, Parsley, Basil (my favourite!) Thyme and Tarragon.
Apart from the wonderful flavour of fresh herbs in cooking and salads, they are also full of all the healthy bits we need, including loads of vitamins.
I have been told that any excess is easily frozen for use later in cooking. You simply rinse in water and then shake and place in a plastic bag, label and freeze. Not yet tried - anyone done this?