Also, container size can effect plant size... A plant will stop growing once it's roots fill up the container. It may even lose vigor and show signs of nutrient deficiency.
Another thing is, a small or medium sized plant loaded with pods will almost certainly stop growing for the period the pods are on the plant (from fruit set to ripening) which for some varieties can be a very long time.
Additional things like frequent wilting from lack of watering and nutrient deficiencies will hault the growth of the plant, which depending on the species, may normally grow very slow in the first place. And if you want a large productive plant you will most certainly need to provide an adequate fertilizer, at the right times and most importantly not too often.
And one of the most important factors is the amount of light they receive, almost all species require 6+ hours of direct sun (Full Sun) and indirect light when not in direct sun (Visible sky without sun, or sunlight reflecting off a bright nearby object) can help as well. Getting less than 6 hours of direct sun a day, and or lots of shade will slow a plant down significantly.
Low Mean Temperatures will also slow a plants metabolism and can cause your plants to be smaller than normal.
Couple this with a late start and a short season, and it's no suprise that a plant isnt growing as large as others you may see here.
Hope that helps you understand, and good luck with next season.