Hey there water flute... looking good there in your neighborhood! OK so down in Australia you should be able to find Kelp Meal and worm castings, 1 cup of each into a bucket of water and stir let sit or aerate over night and water in....
To be honest tho the plants look fine.. usually with outdoor soil grow, prepare the hole with organic sources humus and goodies and put in the hole at the beginning of the season then water if needed... good to go. All your plants look fine. I would NOT use the chemical fertilizer on them at this stage.
First off it's not needed as your plants are healthy and happy.
2nd its not needed your plants look healthy and happy!
Can I ask you a question? Ok 2 questions.... why do you think you need to use the fertilizer??
Cheers