User can only choose amongst appropriate fields that have enough capacity

[askingalot]

Given a user has launched the program
When the user selects the option to purchase seed
Then the user should be presented with a list of seeds to purchase

Given user is viewing a list of seeds
When the user selects a seed
Then the user should be presented with a list of fields that are appropriate for that seed AND have enough room for the new seed

Given user is viewing the list of appropriate potential seed fields
When the user selects a field that has available capacity
Then the user should be presented with a message confirming the field selection
And the user should be taken back to the main menu