I amend the soil with alfalfa pellets whenever I plant anything, even in pots. A cupful or so for a small plant, and more for a bigger plant. At least once per summer I make alfalfa porridge by putting about a quart of pellets into a watering can with 2gal. of water and let it sit in the sun for a few hours, then mix and water it onto anything that needs a boost for the rest of the season. We have a really long season here, so a slow-release nutrient rich amendment is perfect for boosting late summer growth.
I'll top dress with a cup or two any time I see any peaky looking foliage as well. I also broadcast the pellets under my fruit trees after the fruit is harvested again for another shot of slow-release nitrogen for healthy new growth.
Can't say enough about the great growth my plants show with this nice, natural amendment.
