My eggplant and sweet peppers on the other hand are growing but no where as quickly as the tomatoes. The foliage is also more of a lighter shade of green.

Is this because the summer heat hasn't really kicked in yet?

Could it be due to the fact that the tomatoes are in full sun right next to my garage wall and the eggplant/pepper containers are in my garden which receives part shade depending on the time of the day?

The tomato plants in my raised beds in my garden (not in a 5-1-1 mix) also don't have as much growth and are not as dark green as the tomatoes next to my garage. The stems and branches are not as thick either.

I'll try to post pictures later.

All other factors being equal, sun exposure, or the lack of it, makes a big difference. It isn't the 5-1-1 that is the issue since no mix can compensate for less than ideal location/exposure.

Now add to that that both peppers and eggplant are naturally slower growing - especially until mid-summer heat temps arrive since they are both heat lovers - and you understand why they can't accurately be compared.to tomato plants anyway.

Dave

What do you mean by "receives part shade depending upon the time of day." ?

I only ask because if they are receiving anything less than 6 hours of direct sun over the course of the day then they are growing in part shade.

Even 6 hours is not really ideal in my opinion, but we all have to work with the space we have. My gardens get 7 to 8 on average where I'm lucky.

Yes. I believe that is it.
What are your night lows? Under 50F? what are your day highs ? Under 73F?

Both peppers and eggplants need heat (as much as or more than light) to really take off. If your tomatoes are doing fine in the same condition then the only reason your pepps and eggps are not, is because of the lack of warmth.
I am also having the exact the same problem. I expect them to move within next 2 weeks as the weather warms up.

To answer another question, my garden receives morning sun between 7am and 10am, then 12pm to 2pm and then again from 5pm-dark. This is because a large elm tree shades the garden from about 10am-12pm and then my house blocks the sun from about 2pm-5pm.

Kevin

A couple additional items of interest...

-This weekend I covered the raised beds with my first batch of compost of the season to serve as a mulch. I had to screen it first.

-Any powdery residue on foliage is from DE that I applied two weeks ago.

-I am already starting to see some brown spots and holes on my cuke leaves for the third year in a row. Seriously losing hope that I'll ever be able to get cukes to thrive in this garden. My older house just 5 miles away was cucumber heaven.