To make sure that you have something to eat from your garden all you need to do is sow seeds every week.
We have been getting little harvest lately only because I went lazy two months back and sowed no seeds.
Greens, vegetable, vine vegetables, root vegetables, the list is endless. Better still make your own seeds so sowing becomes a real easy job.
Another way of making sure you sow without an effort is to compost your own and regularly add that compost to your containers. This way you get a lot of self seeded saplings all over the garden that you can separate and repot for more yield.
Happy Sowing seeds friends!