Garden Fatigue- or on-going program

A while back, Glenn, the national director for DOOR, likened the running of the DOOR program to growing a garden not building a building. It's not something we build and it's done. Instead it's the kind of thing that takes constant care.
In the case of my garden, it's time to remove the seeds atop the old lettuce stalks, dig under the unproductive tomato vines, keep spraying the pepper plant leaves, plant the new mint and start new seeds. Florida is supposed to have 3 growing seasons. Let's try to get as many as we can. Square foot gardening should indicate we can keep growing all year.
But the warning comes in the example of my mother. She planted much too big of a garden. She's 74 this year and honestly she does not need the production of the 20 or so tomato plants she has. She and my dad cannot eat the remaining 24 watermelons. She canned as many of the green beans as she could and they keep coming. She's been at this since April and she's pooped.
If we run programs in a way that we're overworked, we'll wear out before the harvest is finished for the season.