The essence of this principle is that with whatever energy you are going to contribute to something, there must be a worthwhile result.
We can consider this in many aspects of our lives - work, financial investments etc; but most definitely this applies to what we are cultivating in our food gardens.
Put simply, choose to plant crops that you will acquire a good volume of produce as a result of the level of work you put into your garden, and consider how demanding the plant itself is in terms of nutrients and care. You should also only consider planting foods that you and your family like eating. Why bother planting and harvesting foods that you loathe! As the saying goes, "You can't work on an empty stomach!"
I recently had a pumpkin seedling appear in one of my garden beds. This had just sprouted from compost I had added from my Compost Bin. As I once had success with a butternut pumpkin vine grown in a no-dig garden bed that I had constructed on my concrete driveway, I thought I might try my luck with this vine. Pumpkin vines spread very quickly wide and far! Flowers appeared and the baby pumpkins started to grow. Unfortunately though, whether it be due to the high rainfall lately, the baby fruit started to rot before growing to a decent size. Pumpkins are heavy feeders, so the vine was starting to take away too much from the other plants in my garden bed. I realised that the pumpkin vine 'yield' was not going to be big enough, so the vine was pulled!
Think about the yields that you are obtaining from your energies during April - it might be time to make some changes.
For further information on this Permaculture Principle as well as the other eleven, visit www.permacultureprinciples.com. They have just relaunched their website and it looks fantastic!