Winter growing seedlings going into their first summer

[petershaw]

Do I understand this correctly, that I should keep them growing all summer? I am guessing the bulbs need to grow to withstand a summer dry period in a pot. 

I think I found this recommendation in one of the old Bulb Garden that were just recently posted. 

I am sure there is no simple answer as different species need different treatments. I had some go tan then brown really quickly while others are still green (growing?)

Peter

[David Pilling]

I'd say it is best to keep everything growing as long as possible from the point of view of reducing how long they take to flower and increasing the chances of survival.

Some species will go dormant when temperatures get too high etc. so the gardener has to locate them to avoid that.

The only snag is that some things will never go dormant, that can be a problem, but then again if they throw up new leaves anyway it is OK.

[janemcgary]

I've noticed that some Narcissus species seedlings do not go dormant in conditions here (water while in growth, kept in part shade). They do go dormant the second year, though, and don't seem to suffer by being kept growing.

[Uli]

I agree with the others. There is no general treatment for winter growing seedlings during their first summer. What I do is to group the pots together which need the same treatment. All in shade. Those pots where the seedlings go completely dormant are moved to the dormant group and those which remain at least partly green are kept moist. However, even the fully dormant pots get a small amount of water every four weeks or so. Small bulbs my dry up to death if kept brutally dry for many months, especially in a hot climate. It has also happened to me that seedling bulbs have rotted with too much water during dormancy but this is the exception. I have lost more to drought. All this is a matter of constant learning and close observation.
Uli 

[petershaw]

I agree with the others. There is no general treatment for winter growing seedlings during their first summer. What I do is to group the pots together which need the same treatment. All in shade. Those pots where the seedlings go completely dormant are moved to the dormant group and those which remain at least partly green are kept moist. However, even the fully dormant pots get a small amount of water every four weeks or so. Small bulbs my dry up to death if kept brutally dry for many months, especially in a hot climate. It has also happened to me that seedling bulbs have rotted with too much water during dormancy but this is the exception. I have lost more to drought. All this is a matter of constant learning and close observation.
Uli
Great information, thank you all, 
I have been doing exactly this, those that seem to be constantly green get some water and light fertilizer when they seem dry and those having gone dormant are in my dry area propagation box. I will add some water to them occasionally with this tip, thanks

[Martin Bohnet]

It goes the other way, too: Summer-growing Tigridieae can be grown on until they flower first - at least that's what Molseed states.

[CG100]

It depends on the plant - many will go dormant as the day lengthens and temperatures rise, and they will rot if kept watered.

Many bulbs depend on dormancy to trigger flowering once mature.

[David Pilling]

For each species there must be an optimal strategy for getting bulbs that flower in the shortest time.

For example if you can manipulate temperatures you could generate two (or more growing seasons) per year.

I imagine that if you're earning a living growing bulbs you know about such techniques.

Some species have very short growing periods, and take a long time to reach flowering size.

[Diane Whitehead]

I'd rather wait a while -  the fast growing ones become weeds.

Diane  - still digging out Spanish bluebells after 40 years.

[CG100]

For example if you can manipulate temperatures you could generate two (or more growing seasons) per year.

It is generally (always?) temperature cycles controlling active growing periods, although the warm/cool periods usually need specific minimum lengths to flick the clock over - peonia seeds are a very good example which can be artificially taken through two cycles in one year.

For flowering, it is generally (always?) photo-period, or ratio of dark to light, that triggers things - pointsettias are a very good example.

There are also some plants that grow unlinked to phoo-period or temperature, but grow so long as conditions allow - one comes to mind - some Crinums, which grow so long as there is enough moisture - uncommon in nature, but not so in cultivation. But, they will need a short-long day cycle, and wet-dry, to trigger flowering.

[MarcR]

Crinum like to be moist but not wet all year.  Most south African Iridaceae like a summer rest with little or no water; but benefit from continuous watering the first year. I have not recognized any unifying patern in South African Liliaceae or Amyrilidaceae.

[CG100]

Crinum like to be moist but not wet all year. 

It depends on the species/hybrid and minimum winter temperature.

Ignoring natans and thaianum, my Crinums are all under glass (actually bulbispermum and boophanoides are on a cold, west-facing kitchen window sill) and although x powellii and macowanii can take several degrees of frost, I keep all of them except variable dry for the winter (greenhouse minimum is around 6C), and would not risk things otherwise.
Some SA Crinums are native to areas with very dry, dry seasons, some are baked into something akin to concrete while dormant. During their active growing season, some are semi- or fully aquatic, although the vleilelies are supposed to flower perfectly well if just kept well-watered rather than submerged, with a dry season.