Yellow leaves on tomato plant

[sall2009]

Some of my tomato plants have yellow leaves at the bottom. Could it be due to too much heat? These plants are on the top shelve of my blow away green house. Plants on other shelves seem to be fully green.

Although the plants with yellow leaves, seem to be growing taller than other plants.

[chris]

Do you mean the bottom leaves are going yellow? Seed leaves, or true leaves?

If so, and the rest of the leaves are fine then it'll most likely be that the lower leaves have served their purpose, and to save energy the plant is drawing the cholorplasts from the leaves and using them in leaves further up the plant.

I remove the yellowing leaves - to prevent any means of disease entering the plant.

[rustylady]

Sall, I think you've already asked this question several times on other threads. Your plants probably need re-potting or feeding.

[sall2009]

I have two different sized plants. Small ones are in small pots and others are flowering / fruiting in bigger pots. Ye I have asked other questions about the plants before.

[rustylady]

You say small plants in small pots, and flowering/fruiting in bigger pots. Could you be a little more specific please? How tall are the plants, and what size are the pots (I prefer measurements in inches cos I'm old, but I can convert from centimetres if you prefer)

[Two_Sheds]

Yellow lower leaves indicate that the plant is hungry: repot or feed it

[sall2009]

The smaller ones are around a foot tall and I can just about see signs of first floor truss. Thinking about it now, they do need re-potting. But the reason I asked was because It's only the plants on the top shelf which got the yellow leave. Maybe they need more water.
The bigger plants are 2-3 foot tall and planted in big pots. They are Not in the green house.