When growing tomatoes from seeds or buying small plug plants, we normally transplant them into a 3 inch pot to start with, then maybe a 4 inch then a 5 or 6 inch before we put them in their final position – a large pot/container or grow bag.

These are the pot sizes I use between seed tray and final position.

But why do tomato plants need to be potted on in stages, why can’t we just sow a seed into a big pot to save all that time and messing about?

Here are a few reasons why.

It saves space – imagine having a large pot for each plant sitting in the windowsill – remember that they can’t go into a greenhouse until the end of April and they can’t stay outside overnight until the end of May or when the danger of frost has passed in your area.

More mobile – plants can be moved around more easily in small pots – in the greenhouse or outside during the day and indoors at night.

The most important reason – When the roots of tomato plants reach the sides and bottom of their pots, they “get a move on” or in other words, mature more quickly to the flowering and fruiting stage.

The over-riding goal of a tomato plant is to produce seeds for the creation of its next generation. If it thinks that it has limited resources or room to grow, it “gets on with it” so to speak.

A plant grown from seed in a big pot will not mature as quickly. It will take longer for its roots to reach the sides and will sit around in the sun thinking it has all the time in the world and be lazy – fruiting will take longer!

Of course we don’t want plants to become pot-bound (when the root area becomes much too big for the pot and the plant’s growth becomes stunted), but we do want to pot them into bigger pots in stages and let them “feel the sides” as it were.

Here’s the latest progress on the five Tumbling Toms that were sown on March 4th.

Too Much Sun
Be aware that too much direct sunlight on small tomato plants can cause them to wilt – develop droopy leaves.

If this should happen put them in the shade and spray/mist them with water. They need to acclimatise even to good weather!

If you put them outside in the sun, hang a piece of garden fleece in front of them, or cover them with fleece to reduce the harshness of the sun and keep an eye on them. If they go too long without being revived, they won’t recover.

In a previous newsletter I mentioned about comparing three “early to mature” varieties to see which one would be the first to bare fruit.

Latah, Red Alert and Stupice.

They are all doing well and I’ll show the latest growth in next week’s newsletter.

Do email me or leave a comment if you have any questions …

Best wishes,
Nick

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