At what stage of development and in what type soil should new amaryllis seedlings be planted?

not till you have several leaves , and bulb will be at least a nail size

Fingernail? Marble? Pea? BB?

1/3 of an inch in diameter, but you can wait with that till plants are 2 years old, as long as roots has enough space

@WAMcCormick

WAMcCormick said:At what stage of development and in what type soil should new amaryllis seedlings be planted?

Here`s a quote from `Clemson Extension` (college of agriculture)

A tiny bulblet is evident with the formation of the second or third leaf. After a month, a complete liquid fertilizer of about 200 ppm N is recommended, which may be increased to 500 ppm N at 4 months. After 6 months 700 to 800 ppm N is recommended.
(in other words 1/4 through to full strength of recommended dose)

The bulblets will probably need dividing at the 3-5 month stage, again at 10 months, when you can introduce each bulb to its own pot. When dividing them, use a mixture (by volume) of three parts builder's sand, four parts pine bark (soil conditioning grade), and two parts peat moss. Because of their herbaceous roots, the main consideration is large air spaces in the growing medium.

WAMcCormick said:At what stage of development and in what type soil should new amaryllis seedlings be planted?

They like to be rather crowded. Unless they are pressing up against the side of the pot, crowding each other out, or their growth is slowing considerably, I would leave them be. I water mine with weak fertilizer water.

here mine, about a year old, I only re-potted them in a longer pot, no need to separate them this year.

Here are some of mine after day 26 floating on water. I'm thinking about planting a few in the next couple of days. The ones with a single leaf, maybe 10. I've got some ecoscraps potting mix on hand that I'm going to try but have also wondered about using straight horticultural vermiculite.

Larry, the ones I moved from water at day 15 to potting soil are now growing green leaves 10 days later.

A few of mine at various stages of development.
I have more

Wibbly, you have a pretty big operation going on. They look good. Were they open pollinated, or are you working on crosses?

How are you managing the irrigation?

wibbly said:A few of mine at various stages of development.
I have more

what are u going to do with all this plants when are mature ? I have about 20 blooming bulbs of apple blossom, and it is already too much for me.

@WAMcCormick
[quote="WAMcCormick"]Wibbly, you have a pretty big operation going on. They look good. Were they open pollinated, or are you working on crosses?
Thanks, yes most of them are crosses (mentioned in my other posts)

How are you managing the irrigation?
With these (moisture meter and squeeze bottle)

@sangel

sangel said:

what are u going to do with all this plants when are mature ? I have about 20 blooming bulbs of apple blossom, and it is already too much for me.

That`s a good question I may try to sell them as one, two, and three year bulbs - if unsuccessful I will give them away.