Potting on time for one-year-olds?

[picnic]

These (mixed) seedling are one year old - for scale, they're in a 1.5" pot. Should I be trying to separate them out once we're into the growing season proper?

[Herts Mike]

Yes, I would but not into individual pots yet. I would put them into a tray for this season, giving each one some extra space.

[picnic]

Thanks Mike, what's your reasoning for putting them into a tray though?

[Herts Mike]

It's something I have done for many years and allows them to develop quicker plus they don't dry out as quickly as they would in small pots so the root system gets a good chance..

[habanerocat]

It's something I have done for many years and allows them to develop quicker plus they don't dry out as quickly as they would in small pots so the root system gets a good chance..

Agreed, I don't think it's scientifically proven, but they just seem to develop better when grouped in a single pot together. As said above it could be due to having more moisture.

I accidentally left Sulco seedlings in a watering tray while on a two week summer holiday (remember them?). They responded well with no losses.

[iann]

It's something I have done for many years and allows them to develop quicker plus they don't dry out as quickly as they would in small pots so the root system gets a good chance..

Agreed, I don't think it's scientifically proven, but they just seem to develop better when grouped in a single pot together. As said above it could be due to having more moisture.

I accidentally left Sulco seedlings in a watering tray while on a two week summer holiday (remember them?). They responded well with no losses.

It isn't scientifically proven because it isn't true.

The best time to repot one-year-olds is when they're two-year-olds These are not over-crowded yet, but given that they look like relatively quick-growing species they will be pretty soon. You could wait, pot on as a group now, or just shove each one into a 2" pot. They should be fine with any choice because they aren't touchy die-at-the-drop-of-a-hat types. A tray is a possibility but watch out for the root types. Seedlings with long taproots will not develop well in a shallow tray. Trays also hold water close to the surface, where a deeper pot is wet at the bottom and dry at the top. Use appropriately.

[habanerocat]

It's something I have done for many years and allows them to develop quicker plus they don't dry out as quickly as they would in small pots so the root system gets a good chance..

Agreed, I don't think it's scientifically proven, but they just seem to develop better when grouped in a single pot together. As said above it could be due to having more moisture.

I accidentally left Sulco seedlings in a watering tray while on a two week summer holiday (remember them?). They responded well with no losses.

It isn't scientifically proven because it isn't true.The best time to repot one-year-olds is when they're two-year-olds.

I don't think it's fair to advise novice growers with such hard and fast rules.
The BCSS seed raising leaflet seems to advise the opposite.

http://www.society.bcss.org.uk/images/C ... atemix.pdf *

Everybody to their own I suppose. That's the great thing about gardening.


* Unfortunately the pages seem to be in the wrong order.

[picnic]

Thanks all for the advice - I'll see how much root each one has then decide what to do. Maybe!

[Cidermanrolls]

No hard or fast rule here, but if it were my pot I would have repotted those in the last month, whilst still dormant. I can see at least 14 plants and two or three different vigours. If you don't repot now at least one of two things will happen, the big plants will swamp the small ones and/or the roots will suffer more damage when you finally get around to repotting.
But I might be at one extreme. I've already pricked out this year's epiphylum seedlings and have over 100 growing away strongly having lost just one. If I'd left them in the original pot I might have lost many more to damping off.

[Ali Baba]

interestingly there is quite a lot of research on how seedlings develop and compete for limited resources, as your seedlings are doing in their pot.
In a nutshell, the seedlings that emerge first have an advantage, and the seedlings furthest away from their neighbours have an advantage. In practical terms, sow thinly and pot on as soon as you can handle the seedlings. This will reduce the amount of competition between the seedlings, and is why seedlings pricked out into trays do well, because they are being spaced out so they get more resources.
Of course that only matters if you want lots of plants which will grow as quickly as possible. If you only want one plant, just remove all the seedlings that come up after the first one and you will get a nice big plant in the shortest possible time.
Here's a real life example:

All these pachypodiums are 1 year old, they all germinated on the same day. The one in its own pot was pricked out when the root was 5mm long, so no competition between seedlings at that point.
You can see that the seedling top left is furthest from its neighbours, and is larger than the other 4. The top and bottom right seedlings are about the same size, and smalller than the largest, the one in the middle has to compete with 3 surrounding seedlings and is the smallest by far. The one in its own pot is much larger than the ones in the community pot.

If you are interested in the research, not about cacti, but lots that applies in practice to raising any plant from seed, you could read Popoulation Biology of Plants by John L. Harper, your library should be able to get you a copy.