Healthy gardens and greenhouses

Well, the new year is almost here so it's time for me to kick into seeds and gardening 22/7. (see. I am pacing myself. no more 24/7)

I just saw a poster for herbs to keep a garden healthy and its below. I believe this was on Mountain Rose Herbs

It made me think of all the ways to keep a garden healthy (happy) and since the one greenhouse will be going active soon, healthy greenhouses too.

Do you guys have ideas that work for you? Unhappy gardens have more insects and plant disease.