corn basics

I always put a small handful of chicken pellets in the hole, fork it in a little bit, water the hole and then plant them in 

Thankyou - very helpful, will search out some chicken pellets x

Agree with first 2 replies - depending on variety sweet corn will grow to at least 5' which makes them very hungry plants (they don't like the cold either, but you can't do anything about that if it happens.)

A few canes and horizontal stringing surrounding and diagonally through the block of plants will help them stay upright, especially if you are growing a tall variety on a windy site.

I see yours are described as dwarf Snoozie - what variety are they? (still think it's unlikely they'll be less than 5')
15-18" spacing is often recommended, although I usually push that to 12" with the shorter varieties.