transplanting 1 year old seedlings

[petershaw]

I did some searching on the site but didn't find what I was looking for.

Last season I received an envelope "all the rest" full of seed packets.

Being enthusiastic I sowed almost all of them.

Most are dormant and many are winter growers so the season might be starting soon and I want to know if I should transplant some and send others to the bulb exchange.

I recall reading that its best to let them go another year.

Suggestions?

[CG100]

Most bulb/corm/rhizome seedling are no great size at a year, lots never make any size even when flowering size, and a few of the biggies romp away within 12 months.

Horses for courses.

Unless any are exceedingly closely packed, I would leave them as they are, and even closely packed ones are probably best just "dropped" into a larger pot rather than actually separating and transplanting them.

[Uli]

I pot my seedling bulbs up into bigger containers only after they start to grow in their second season. This way it is easy to judge which ones need potting up and which ones don't. If the pot looks overcrowded I repot,  if not I leave them in the original pot for another season or even two. I have never ever lost seedlings this way. But of course, I don't undo the rootball and would not dream to separate them. 
Regardless if potted up or not, all seedlings which start into new growth get their first dose of a balanced fertilizer low in nitrogen.

Uli 

[petershaw]

Regardless if potted up or not, all seedlings which start into new growth get their first dose of a balanced fertilizer low in nitrogen.

Uli

Thanks, this leads me to my second question: Waking up. 

Triggers (horses of course), cooling temperatures, shorting days and rain fall correct?

Do you encourage this by watering them in the fall (its now almost September)? I am moving them outside from the protected dry area in my greenhouse but our "Indian summer" in CA is really just getting started.

[Uli]

Hello Peter,
Waking up dormant winter growing bulbs in autumn seems to depend on several separate factors. As you say, cooling temperature, especially soil temperature and moisture. I dont know about day length because underground bulbs cannot really "see" the daylight, but it might also play a part.
I find some bulbs do seem to have an internal clock because they sprout regardless of temperature or moisture (are they the day length dependent ones?) and with others it seems to be a combination of all factors.
I do not water my adult dormant bulbs, neither in the ground nor in pots. But I use large pots of at least 6 litres (see my article in the Bulb Garden about Companion Planting) But I do water my dormant seedling bulbs with a light overhead watering by hand with a fine rose every 4 weeks or so. They are in square 8x8x9cm pots and would dry too much if not lightly watered. All pots with dormant plants are kept in shade during dormancy because otherwise the black plastic pots wout become far too hot. If I do not move them early enough the plastic labels would deform from the heat.
Uli

[petershaw]

Yikes, mine are really dry. I will give them some water today and hope for the best.

Peter

[CG100]

Horses for courses again.

Don't forget that some bulbs have deciduous roots, some perennial, another factor. As for the trigger - there will be data posted online somewhere, but I suspect that the great majority of bulbs use more than one trigger for regrowth and/or going dormant.
Certainly some bulbs use chemical compounds in their flesh that act as clocks - the bulb may have to be over or below a certain temperature for so many days before cooling or rising temperature triggers growth - this is why simply changing temperature artificially seldom triggers an immediate response. Once the time has passed, and temperatures are dropping or rising, there is then the question of water being available, or not.

For instance, Lachenalia here make leaf growth while still totally dry, and they have deciduous roots. It will be time and changing temperature that triggers them, probably nothing else.

As for moisture during dormancy - same again - desert species may require to be near or totally dry, lots of spring bulbs are unaffected by moisture during dormancy.

[Uli]

What do you mean by horses for courses?
Please don't forget that not everybody in this world is a native English speaker.....
Uli 

[David Pilling]

What do you mean by horses for courses?

There are two types of racing course, the flat, and the steeple chase (over jumps). A horse that does well on the flat will not do well going over jumps, and a horse that goes well over jumps will not win on the flat.

Each horse to its own speciality. Different bulbs need different treatment.

There are also pantomime horses with people inside, suitable for the stage, and wooden rocking horses suitable for the nursery. Plough horses and dray horses for pulling heavy loads. Dressagae horses, dancing horses.

In brief, horses for courses.

[Uli]

Thank you, David for this explanation 

Uli 

[CG100]

Peonia seeds are a good example of growth requiring more than one stimulus/trigger.

In the open, peony seeds germinate the spring after they ripen and produce just a root. In the second spring after riepening, they produce their first leaf.
This can be shortened to one year by placing the seeds with roots into a refrigerator for 4? 5? 6? months (someone here will remember), which is enough to "tell" the seed that it has been through a second winter. A shorter period in the cool does not work.
They require temperature and time as triggers.

In the one or two examples that I have seen explained in research papers, the bulb contains a growth-inhibitor that is generated during growth, and which breaks-down slowly after the bulb goes dormant, so acts as a clock/calendar.

Many bulbs use fire as a trigger for growth and/or flowering (or at least the products of combustion - at least one active chemical from smoke has reasonably recently been discovered).

Lots of seeds certainly require light before they germinate and may remain dormant for tens, perhaps hundreds of years if in the dark - poppies are a good example and are the reason why, in Europe, the field poppy is associated with (the end of) war, especially the end of WW1, when poppies covered the battlefields in France and Belgium after the guns fell silent - the soil had been "ploughed" to great depths by shelling, bringing the old and ancient seeds to the surface.

[David Pilling]

Reminiscent (growth inhibiting chemicals) of the work of the retired Chemistry Professor Norman C Deno on the germination of seeds.

See the wiki page:

https://www.pacificbulbsociety.org/pbswiki/index.php/HowToGrowBulbsFromSeed

which links to copies of all the volumes of Deno's books.

[janemcgary]

I've been familiar with Deno's work ever since he started publishing it, and I would warn that it isn't always the last word on individual genera (which can have variation among their species in this regard). This is especially true of the Ranunculaceae, even within Ranunculus and Anemone. Deno tended to be doctrinaire in his pronouncements. I once heard him tell someone that you can't claim to be "growing" a plant until it is "self-sowing in your garden." He had a large garden in Pennsylvania, USA. Finally, I agree with others' advice on leaving many kinds of bulb seedlings in their original pots for two years, or moving the mass of seedling bulbs together into a large pot. I moisten the mass slightly, put it in the partly filled larger pot, and press it gently to spread out the mass some, then cover it with a few cm of new soil. Some kinds of bulbs, notably Calochortus, Tulipa, and Erythronium, tend to extend deeper rather quickly during their maturation periods.