Spacing and plant health

The kale and beets are growing steadily, but I think I may have overcrowded the container. With the kale, it is clear that the container with fewer plants is doing better. I want to thin out the crowded container, but rather than pulling the plants I plan to transplant them to another container. I am fresh out of containers, so I will either have to go buy more or use smaller containers and plant one per pot. Unlike the kale, the beets in the smaller container (presumably with less root space) is doing better than the larger container. The spacing is about the same and I also used the same soil so I don't know what's going on.

Container on the left is a ~3 gallon container and the right a ~5 gallon container.
The beets were started and transplanted at the same time but the plants are larger in the smaller container.

I also transplanted 2 mild jalapeno starter plants into self-watering containers (3 gallon) I found at Lowes. This is about the same size as the 13" Mainstay self-watering container I buy at Walmart. They are about the same price but I think the Mainstay container is better quality. Anyway, I've started a little experiment with the jalapeno plants. In one container (the middle) I used 100% new potting soil, and in the other I used recycled soil with fertilizer and cow manure.  It'll be interesting to see if there are difference between the two.

The grey containers are the new from Lowes. The white one is the Mainstay container that I have been using.
The middle container I used fresh potting soil. I used recycled soil in the container on the far right.

I have spotted some aphids on the pak choy plant from last season that is beginning to seed. The aphids are attracting ladybugs! 

I also spotted the first set of flowers on the bush early girl plant this weekend. I am a little concerned that it is too early to leave the tomato and jalapeno plants outside, but it has been quite warm so hopefully all the plants will thrive.

Bush Early Girl flowers