What triggers dormancy?

jobranch · Post by **jobranch** » Oct 12, 2007 6:23 pm

What causes hostas to fade and go dormant at the end of the season? Does this happen with the first cold snap or is it the first frost or something else? My hostas are still up and some still looking good, but I have a few that are starting to droop (mainly Undulatas), and am wondering if they are starting to go dormant.

Jeff

Wild Dog · Post by **Wild Dog** » Oct 12, 2007 8:12 pm

Daylength and temperature and after flowering the dormancy triggers go off, it may take weeks but daylength is main trigger.

John · Post by **John** » Oct 12, 2007 11:26 pm

Shorter days combined with lower temperatures induce dormancy, flowering does not, being day-length sensitive itself: early blooming hostas are not necessarily earliest to go into dormancy, which will vary from hosta species to species, and even from cultivar to cultivar.

Wild Dog · Post by **Wild Dog** » Oct 13, 2007 11:11 am

flowering does not, being day-length sensitive itself: early blooming hostas are not necessarily earliest to go into dormancy, which will vary from hosta species to species, and even from cultivar to cultivar
John

I should have been clearer, all specie's have a cycle specific to that plant but in general it is similar.
Dormant
Spring soil temp rise, emergence
Bloom regardless of when
Dormant

After bloom the process of going dormant begins and varies all over the place but after bloom the plant is going to go dormant regardless of when.

I have no proof but I believe to control for a long growth season or rather get 2 seasons in one, would require controlling temp and daylength to keep the plant from blooming.

I further suspect hosta is a northern hemisphere plant that knows when fall is and will go dormant when the earth moves to fall.

Jamie · Post by **Jamie** » Oct 13, 2007 11:24 am

Jeff,
To give you a simple answer like John's. It's the mixture of less light and cooler temps that start fall dormancy. Blooms have nothing to do with dormancy at all. A hosta doesn't need to bloom to go dormant.

Wild Dog · Post by **Wild Dog** » Oct 13, 2007 1:18 pm

A hosta doesn't need to bloom to go dormant.
Jamie

The part of the cycle when a hosta is going dormant it is also sending food for storage to the roots, so the hosta dosen't 'have" to bloom to go dormant but anything that interferes with the cycle interferes with next springs growth.

Not so simple but some may want to know more than a simple answer.

thy · Post by **thy** » Oct 13, 2007 1:43 pm

It is simple if you is a hosta I'm sure.. but not more than a simple question.

Blooming have nothing to do at all...agree
Daylenght ?????? My hostas was one month ahead when they started to go dormant
Temps... can be ..we had one cold night late August, no frost, but special cold

jobranch, go read the ... ´How many days can a hosta live topic... my qyestion is similar to yours

So far.. I'm on a suddently drop in temps answer

Pia

Jamie · Post by **Jamie** » Oct 13, 2007 6:15 pm

A hosta that doesn't bloom will have no effect on the plant yearly. Been there done that already and seen with my OWN eyes there was no effect of the plants.

John · Post by **John** » Oct 13, 2007 6:24 pm

That is my personal experience too, Jamie.

Wild Dog · Post by **Wild Dog** » Oct 13, 2007 8:25 pm

That is my personal experience
John

How did you measure these observations?