Tomatoes: A not-so-scientific growing experiment. Week 7 update

Updated: Sep 14

We’re really close to our first harvest in the compost / soil experiment! Two tomatoes are particularly close but aren’t quite ready to be picked.

Tomato plants in various amounts of compost and topsoil
Week 7 update: compost / soil experiment

I am still getting some yellowing of my lower leaves across the majority of plants. My guess is that it may be nutrient-based. For example, they could be giving their nitrogen to newer leaves (because it happens as the plants grow). I don’t think that it is an iron (this usually shows on the newest leaves and they are looking great!) or magnesium (usually shows as spots and I am not seeing this) deficiency.


It is also possible that it is disease based. However, since the plants are in different pots using a freshly made topsoil—a mix of varying levels of soil and compost—I’m not guessing this is likely. The plants are also spaced 24 inches apart (I wish I had given a little more space) so I think that the tomato plant leaves are able to dry out from any moisture.


Here are this week’s stats:


Plant 1:

0% compost, 10% topsoil

Height start: 14.5”

Height today: 56.5”

Growth: 290%


Plant 2:

10% compost, 90% topsoil

Height start: 16”

Height today: 53.5”

Growth: 234%


Plant 3:

20% compost, 80% topsoil

Height start: 14”

Height today: 39.5”

Growth: 182%


Plant 4:

30% compost, 70% topsoil

Height start: 14”

Height today: 45”

Growth: 221%


Plant 5:

40% compost, 60% topsoil

Height start: 16.5”

Height today: 54.5”

Growth: 230%


Plant 6:

50% compost, 50% topsoil

Height start: 16.5”

Height today: 51”

Growth: 209%


Plant 7:

60% compost, 40% topsoil

Height start: 14.5”

Height today: 55”*

Growth: 279%*

The plant fell over in week 5 and had about 10 inches of sideways growth that is not reflected in the numbers.


Plant 8:

70% compost, 30% topsoil

Height start: 13.5”

Height today: 55.5”

Growth: 311%


Plant 9:

80% compost, 20% topsoil

Height start: 13”

Height today: 54”*

Growth: 315%*

The plant fell over in week 5 and had about 10 inches of sideways growth that is not reflected in the numbers.


Plant 10:

50% compost, 50% topsoil

Height start: 15”

Height today: 45”

Growth: 200%


Plant 11:

40% compost, 60% topsoil

Height start: 10”

Height today: 53”

Growth: 430%


Plant 12:

30% compost, 70% topsoil

Height start: 10”

Height today: 52”

Growth: 420%

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