What counts as a plant? Coffee, potato, ketchup and 17 other questions

What counts as a plant? Nearly everything that comes from a plant and that you can name, which is a wider net than most parents expect. This article belongs to the family version of 30 plants a week. Coffee counts, once, which is the first thing most people check.

The rule in one paragraph

A plant is a plant food you can name. There are 8 types: fruit, vegetables, legumes, whole grains, nuts, seeds, herbs and spices. Each plant counts once a week, however often you eat it. Tomato on Monday, Tuesday and Friday is 1 plant, tomato and cucumber is 2.

The 30 comes from the American Gut Project, where adults who ate more than 30 different plants a week had a more varied gut flora than adults who ate 10 or fewer (McDonald, 2018). It is an observation in adults, and we use the number as a guideline to count towards together, never as a promise.

The table of doubtful cases

The short answers first. The explanation per row follows below.

What you eat or drink	Does it count?	How many
Coffee	Yes, the bean is a seed	1 plant
Tea	Yes, the leaf	1 plant
Chocolate	Yes, the cacao	1 plant
Potato (boiled, mashed, chips)	Yes	1 plant
Chips and crisps	The potato yes, the oil no	1 plant
Bread	Yes, the grain	1 plant per grain
Ketchup or pasta sauce	Yes, the tomato	1 plant
Fruit juice	Yes, the fruit, with a footnote	1 plant
Tinned mixed beans	Each kind of bean on its own	1 plant per kind
Herbs and spices	Yes, even a pinch	1 plant each
Popcorn	Yes, the corn	1 plant
Rice	Yes	1 plant
Frozen and tinned	Yes	Same as fresh
A pea and a chickpea	Two different plants	2 plants
The same apple twice	One plant	1 plant
Peanut butter	Yes, the peanut is a legume	1 plant
Olive oil	We do not count oil as a plant of its own	0
Sugar	Not as a plant of its own	0
Mushrooms	Yes, we count them	1 plant per kind
Tofu	Yes, the soy	1 plant

Coffee, tea and chocolate

Coffee, tea and cacao all come from a plant, and each counts as 1 plant a week. You count the plant, not the cup. What goes in alongside, such as milk or sugar, does nothing for the count. A child does not drink coffee, so in a household this one is mostly a pleasant start for the adults.

Potato, chips and bread

The potato is a vegetable in the count, even when it sits on the plate as the starch. Boiled, mashed or as chips it is the same plant. With chips the potato counts, the oil does not count as a plant of its own. Bread counts through its grain: wheat is 1 plant, and a loaf with oats and rye in it brings 2 more. Wholegrain is the more useful bread, and white and wholemeal wheat bread are still the same plant.

Ketchup, pasta sauce and juice

A spoon of ketchup is enough to write the tomato down, and in a pasta sauce the onion and garlic count separately. Juice counts as the fruit it was pressed from. For a child's tasting count a piece of fruit is better than a glass, because the child then meets the colour, the bite and the smell. The juice counts for the household, the piece counts for the card.

Mixed beans, a pea and a chickpea

A tin of mixed beans is not 1 plant but as many as there are kinds in it: kidney, white bean and chickpea make 3. A pea and a chickpea are two different legumes, so 2 plants. The same plant in another form, such as hummus and boiled chickpeas, stays 1.

What counts as a plant among herbs and spices

Each herb and each spice counts as its own plant, even when you use a pinch. Cinnamon in the porridge, parsley over the soup and cumin in the stew make 3. It is the category that grows fastest, because nobody has to eat anything extra. A pan of curry with cumin, coriander, turmeric and chilli is 4 plants on its own.

Why the rule is generous on purpose

The rule is generous because the point is variety, not bookkeeping. A household that doubts a pinch of cinnamon is better off spending 2 seconds on it and counting on than holding a debate at the table. If a doubtful case takes an hour to settle, count it and move on.

For children the generous rule works in their favour. Whatever a child tastes counts towards the household total, even a lick. The child is never measured against anything. Their own count is the tasting count: most children need 8 to 15 tastes of a new food before they accept it, sometimes more.

What backfires

• Debating every case. If a doubtful case causes a quarrel, the rule has become too strict. Count it and go on.
• A child's plate as a score. A child who hears that their plate counts has a reason to refuse.
• Cooking twice to reach the number. One pan with several plants works better than two dinners.
• The number as a verdict. A week of 12 plants is an ordinary week.

How Project Food counts this

Project Food is an app on your phone that counts with you, and with everyone at your table. Every plant is a card, and a card levels up by tasting, at 1, 5 and 10 tastes. Herbs and spices are in it, each as its own card. The catalogue holds 230 plants (checked 2026-10-23). After a meal you tap what was on the table and the app counts per plant. It is a counter, and something to talk about at the table, and it promises nothing for a child.