Pricking out to Small Modules and Potting On

Previous years I have pricked out most plants to 9cm round pots. They then grow on until planted out some time in May. Convenient to plant out with a bulb planter, so relatively quick.

This year everything late, light quality dreadful, I wanted to maximise what I could get under grow lights, so I pricked-out to flimsy 1" module seed tray liners. The plants have done well and I have had almost no losses (whereas with 9cm pots in the past I have had "some"). My guess is that some pots, in the past, got more water and the plants got waterlogged, whereas with 1" modules there is less compost and thus less risk of that.

Today I potted-on my first batch from 1" modules to 9cm pots. Agggghhhhhh!

Nightmare to get them out of the 1" modules "cleanly". I tried various methods of tugging and pinching the undersides of the modules to "free" the contents, and also "pushing up" on the bottom of the module. All the messing around with the underside of the module tray distorts the individual cell somewhat, which then makes it harder to get the rootball out of.

The method I found worked best was to take a rigid plant label (I had loads of them to hand, the blade of a table knife or similar would do) and work down & around all four sides rather like releasing a cake from a baking tin. I then got 90% out "cleanly", but the other 10% came away with the roots being dragged out of the compost (so no better than normal pricking out, and they will be set back fairly I suspect ...), or the rootball partly/completely falling to bits.

But it was a SLOW process :(

I wondered:

How about getting some 1" pipe (square plastic tube, rather than round pipe perhaps?) and cutting it into lengths the depth of a seed tray and pricking out into those? They would be open-bottomed, and straight-sided, and it would be easy to push plants out of them at the potting-on stage.

Another possible benefit would be that they could be spaced apart, if the need arose.

I did wonder about newspaper pots too, but fiddly to make that small, and I would need a LOT of them!

I have some more to prick out so might try a tray and see how I get on.

Nicotiana was probably the worst, as the plants had developed well and the brittleness of the leaves meant that pretty much every plant lost one leaf in the process.

Upside was that some things were able to be potted on deeper where the plant had, after the original pricking out, elongated the stem to the seed leaves.

 

I'm glad you posted about this Kristen because only yesterday I was wondering how I was going to get my seedlings out of the flimsy modules when the time comes to prick them out. I'm a beginner and if you had problems, I'm going to be involved in some right fun and games! Like John says, mine have those pencil sized holes at the bottom so maybe it will be easier. I've yet to find out - just hope my seedlings don't get mangled in the process!

 

The best ones I've found for getting everything out intact are the ones from Poundland/99p shops with the 20x round cells, but they don't fit in seed trays and need putting in 'blue plastic mushroom boxes' for support/transportation.

The trouble is that Poundland have stopped selling them this year.

 

Not that keen on using them as one-time usage :( (the older, and greener, I get them more I hate waste ...) plus I reckon just cutting them open would be pretty time consuming too? Dunno how many seedlings I have pricked out / still to do ... somewhere between 500 and 1,000.

I've had those, and they have worked well. Only ones I have had have been minute though ... 1/2" at the most.

Suggest you start with what I found works best - and report back if you find a better way! Pushing something flat around all four sides to "release" the plant from the cell. Provided the roots have not done a helter-skelter impression underneath the module I think you will be all right.

Might be mis-guessing from the photo, but they look nearer to 9cm than 1" ? (In the past I have pricked-out to 9cm, but this year to 1" modules)

Apart from the difficulty of getting them out :( I think the plants have done better this year than previously with 9cm ... so keen to repeat the pridck-out and pot-on in future years, but I do need to refine it.

Anyone any views on 1" pipe/tube, round or square, cut into short lengths [i.e. open bottomed] as an alternative? Been in to town today and didn't think to buy a length for a trial Doh!

 

Quite a few people use toilet roll tubes Kristen, worth a try perhaps.

 

My seed-raising guru, Peter Thompson, convinced me a long time ago that round modules/pots etc were a chronic waste of limited space Think how many small, square pots can be fitted together!
For getting seedlings out of modules, one tip is to make sure that they are given a really good soak beforehand, then ease out with a knitting needle or sturdy plant label. The stubborn ones get tipped upside down and pinched/shaken

 

Yes, good point. That's the same thing, just on a bit bigger scale.

I think that's not necessarily so obviously proven. Staggered rows of round pots will snuggle tightly such that the density of pots-per-unit-area is much the same; down to personal preference thereafter. There was a thread not so long ago where a number of interesting views were voiced, but I think in this case the factor, for me, would be how easily the plant came out of the container during potting-on - whether round or square!
http://gardenerscorner.co.uk/forum/threads/square-vs-round-pots.50075/#post-650848