Tomatoes have stalled ......?

[ourarka]

I sowed my toms/peppers/chillies in modules in February and they germinated well and grew happily in an unheated conservatory, albeit slightly leggy. A fortnight or so ago I potted them on, being sure to bury plenty of stem, and they just seem to have stalled. We have had some great weather so daytime temps and light have been good, with absolute nighttime minima of 9C (normally 12-13). Am. I just being impatient, or is there anything I can do. A few are a decent size but most just seem to have stopped over the last 10 days or so.


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[Mikey]

When you pot on, it will take your plants time to adjust to their new surroundings and make the most of it. So just because you can't see growth doesn't mean there isn't any, they could be really busy underground filling the new pot.

[rustylady]

They will be busy making new roots. What size pots did you put them in?

[ourarka]

Potted them up in to the big standard 9cm square pots ........ your comments are reassuring. Can't upload photo for some reason but the best are around 4" tall with 2-3 sets of true leaves but most are around 2" tall with 1 set of true leaves. They seem healthy in that they aren't yellowing, keeling over, showing any signs of damping off etc ... so hopefully they are busy under the soil!


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[Mikey]

I'd have potted on into a 2 inch pot first, before going up to a 4 inch. They are probably feeling a little lost in there at the moment.

[ourarka]

I'd have potted on into a 2 inch pot first, before going up to a 4 inch. They are probably feeling a little lost in there at the moment.

Lesson learned, thanks. Presumably they'll recover?


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[Bill HH]

Can someone tell me why plants like to be repotted into the next size up and not into a much larger container? How do they know where the sides of the pot are? Logic seems to dictate the bigger the pot the less times the plant is disturbed.

[Madasafish]

bigger pots take longer to warm up. If you are a little plant whose roots are not long enough to reach the sides - which will be warmer during the sunlight hours- then your roots will have less incentive to grow.



That's my theory...

[Martin H]

With most plants, the roots head out until they reach an obstacle before doing a lot of branching. If you put on just a size or two at a time, they make a good mass of roots at each stage; but if you put them into a huge pot straightaway then most of the roots will be at the edge with dead space further in. That dead space can become waterlogged and stagnant resulting in problems, as well as wasting compost.

The plant that got to the big pot in stages is likely to be bigger and stronger with a more extensive root system than the one that went straight in.

Or so I've heard. I've never done a scientific comparison. As it happens, though, I've got 2 identical Hopscotch pepper plants just about ready to pot on. I think I will see what happens if I skip a pot size with one of them...

[solanaceae]

try this

http://www.growfruitandveg.co.uk/gra...ion_77840.html

[Bill HH]

With most plants, the roots head out until they reach an obstacle before doing a lot of branching. If you put on just a size or two at a time, they make a good mass of roots at each stage; but if you put them into a huge pot straightaway then most of the roots will be at the edge with dead space further in. That dead space can become waterlogged and stagnant resulting in problems, as well as wasting compost.


The plant that got to the big pot in stages is likely to be bigger and stronger with a more extensive root system than the one that went straight in.

Or so I've heard. I've never done a scientific comparison. As it happens, though, I've got 2 identical Hopscotch pepper plants just about ready to pot on. I think I will see what happens if I skip a pot size with one of them...

Ok but what about plants put outside in the ground, no pot sides to touch there?

[Martin H]

Ok but what about plants put outside in the ground, no pot sides to touch there?

They spread out as far as they can. No constraints, no worries.

[Kristen]

I sowed my toms/peppers/chillies in modules in February and they germinated well and grew happily in an unheated conservatory, albeit slightly leggy. A fortnight or so ago I potted them on, being sure to bury plenty of stem, and they just seem to have stalled. We have had some great weather so daytime temps and light have been good, with absolute nighttime minima of 9C (normally 12-13).

They may be too cold at nights. Normally minimum temperature stated for Tomatoes / Peppers etc. is 10C. A conservatory attached to the house is likely to be pretty sheltered, and your location is down on the South coast, so probably quite mild ... but sown in February they may have encountered colder temperatures. Tomatoes do tend to stall if they get cold, and it takes several days of properly warm weather for them to get going again. If (they have suffered some cold the leaves often taken on a purple-ish hue - from memory its caused by Potassium starvation, caused by the cold)

Potted them up in to the big standard 9cm square pots ........ your comments are reassuring. Can't upload photo for some reason but the best are around 4" tall with 2-3 sets of true leaves but most are around 2" tall with 1 set of true leaves. They seem healthy in that they aren't yellowing, keeling over, showing any signs of damping off etc

From modules to a 9cm pot is fine. You'd struggle to get them into a pot that was any smaller!!. If they were seedlings being pricked out direct to a 9cm I would think that was on the large side, but from modules is fine.

Can someone tell me why plants like to be repotted into the next size up and not into a much larger container? How do they know where the sides of the pot are? Logic seems to dictate the bigger the pot the less times the plant is disturbed.

As stated above it ensures that the rootball is formed stage-by-stage so that once in their final pot size the rootball is dense throughout the whole pot and can maximise water / nutrient uptake.

Another thing which I think is key is watering. If you put a small seedling / plant immediately into a large pot its small root structure has to deal with the amount of water that the compost in the large pot can hold. It may take the plant a week to "drink" that much - mean time the compost is waterlogged, and airless, and if you water it some more in that time you will compound the problem. If instead you put the plant into a smaller pot it will be able to drink the water more quickly - so much less chance of accidentally over watering it.

Over-watering is very hard to fix - under watering is easy - just give it some water! so of the two under watering is preferable. Once you start having to water the plant very frequently its a pretty good sign that the rootball is getting crowded and its time to pot on. I generally pot-on to a size that allows about a finger's thickness all around the rootball in the new pot - enough room to use my fingers to push down the new compost - but only just! so about 1" - 1.5" extra diameter. Once the plant is in a relatively large pot, say, 6", then it will more easily tolerate moving up to a larger pot - so 6" to 9" ,or maybe even directly into 12", is more likely to be fine than going from seedling direct into a 9cm pot, or from small module direct to 5" pot

[kathyd]

Well... just to be difficult! ... My tomatoes also seem to have 'stalled', and they're in the first size potting on pot, and have been coddled in a trough with a heated cable in, uncovered during the days and bubble wrap chucked over at night. They grew on fine at first, now seem to have stopped, but all looking happy and healthy. No roots showing through at the bottom, and certainly not pot bound, but a 'reasonable' number showing inside when I tip one out. Didn't happen last year, last year I couldn't pot them on quick enough! So I'm putting it down to one of life's great gardening mysteries, of which there seem to be many! And possibly a slightly colder snap for a few days which slowed things down, even in their coddled conditions. And I'm repotting today, all being well .

[Scarlet]

Ok but what about plants put outside in the ground, no pot sides to touch there?

I bet you drove your Mum nuts....