Which items are required for the "Polyculture" achievement?

A complete list can be found here on what needs to be shipped:

Spring:

• Parsnip
• Green Bean
• Cauliflower
• Potato
• Kale
• Garlic
• Rhubarb

Summer:

• Melon
• Tomato
• Blueberry
• Hot Pepper
• Wheat
• Radish
• Starfruit
• Hops
• Corn
• Red Cabbage

Fall:

• Eggplant
• Pumpkin
• Bok Choy
• Beet
• Yam
• Cranberry
• Amaranth
• Grape
• Artichoke

In addition, the guide also states strawberries (spring) and coffee beans (spring or summer) or also needed. A user in the comments in the guide (and here) also states that flowers are not necessary (they have been removed from the quote).