Skip dormiancy with artificial light and temperature

[DavTom]

Hello,

Sorry if this topic is already addressed somewhere.

I am wondering if and how much orchids that go dormient in nature can be forced to grow/bloom continuosly via artificial light and the right temperature. As we all know, orchids are slow growers compared to most plants...so, avoiding the winter rest would be handy, if feasible...

Anyone has had direct expirience on that, especially with orchids that are known to go "very" dormient in nature? For instance, Phals do NOT require much dormiancy...

Some plants, like the Venus Fly Trap, will simply die off after a few years without winter rest.

Thanks in advance.

Cheers,
Dav

[alecStewart1]

I have several carnivorous plants and I can tell you there aren't many orchids that have a "dormant" period like venus fly traps or sarracenia do where they kill off their leaves and go into their rhizome.

For Phals, as you mentioned, they'll get rid of their flowers and flower stalks and their leaves might droop down some. It's considered a "rest" period as opposed to a true dormancy.

[Roberta]

By contrast, Catasetinae go very dormant - when they need to get NO water. And there are a lot of orchids in between... A dry period, or a cold period, can trigger blooms. If you don't observe the growth needs of the plant, you may end up growing a lot of leaves. Most of us grow orchids for the flowers, to get those you do need to pay attention to the growth pattern of the plant. The needs vary by genus.

[plantxart]

I wouldn’t recommend doing that.
Orchids are a very big group of plants that comes from different places and have different conditions to thrive. You might get away with some doesn’t really require full dormancy. Attempting to skip this phase could disrupt their natural growth cycle, potentially resulting in stunted development and reduced flowering. It's best to allow orchids the rest they need for optimal health and beauty.

Cymbidiums for example, need a cold period to bloom. You can skip it but they just won’t flower

Actually a lot of terrestrial orchids go into dormancy. Just on the top of my head: Habenaria, Hemiphilia, Calanthe, Thelymitra, Ophrys, Orchis etc.

Members of the catasinae family - catasetums, Clowesia, cycnoches mormodes will lose their leaves in the winter and just pseudobulbs remain. It is important to respect these growth cycles for better plant growth

[Roberta]

In general, if you don't observe the needs of the orchid, you won't get much of anything. Phals don't go dormant, but they need about 12 hours of good indirect light to bloom. Again, give them less and they'll grow leaves but not flower. And if their habit is to produce flower spikes once a year, that's what they're going to do - at best. Give them less optimal conditions and that can go to zero. If you want plants that do things fast, don't grow orchids! Progress is measured in months or years. They are sloooowwww.

[Leafmite]

I have heard of this being done to prompt Cattleyas to put out new growth when they are rootless and in poor condition coming into autumn. The other alternative is to keep the Cattleya in a terrarium with ample humidity until spring.

[DavTom]

Hi all, many thanks for all your feedback.

But, has anyone of you tried to hit orchids that are well know to go dormant in nature with optimal light/ temperature etc... 24/7 for at least one year?

The feedback received so far seems more based on common sense and literature rarher than on personal experience. I trust real experience more...for how many decades people believed that low N and hight P was required to promote flowering?...

Ok, let me share my personal expirience. I have hit Phals with optimal light/temperature 24/7 for 1 year. They grew and bloomed crazy with so many lasting flowers thar illuminating the leaves with spor lights became almost impossible as the flower were shading everything. Following year I did not use artificial lights and growth/blooming was much reduced Still nice, but not comparable at all.

With other orchids like Bulbp, Cattl and Dendr it did not work so good. Cattl and Dendrob doing well, but nothing exceptional, and Bulbp not flowering much...

Cheers,
Dav

[plantxart]

ok, skipping dormancy for orchids that go dormant is a thing and running grow lights 24/7 for 365 is another thing. Not sure what you're getting at.

And don't get me started on fertilizers. You mean high phosporous fertilizer? That has been debunked by literature

Plants need a period of darkness for respiration. To run grow lights 24/7 in the long term is detrimental to their health.

You're probably wondering why you're den, catts, bulbs did not do well but your phals did. Well, these phals have been bred for big beautiful flowers that last for months. It might not work with a species like a schilleriana. In nature, they follow a pattern and use natural cues such as light and temperature to grown and bloom.

[estación seca]

As far north as you are, supplemental lighting makes a big difference in flowering. Phals are low light plants that grow all year. Roberta mentioned day length is important for flowering. So it is understandable supplemental lighting would make a big difference with them.

Catts. are high light plants. Many species get more light in winter due to trees dropping leaves. Too long a day length may prevent them from flowering.

There are many different Dens. with different seasonal water, fertilizer and light requirements. You can't generalize care for them. Some definitely flower better with more winter light.

If a Bulbo. isn't flowering, the commonest cause is inadequate water. Most like to be very wet at all times.

[DavTom]

Sorry, my fault - I was not clear with my 24/7 statement.

I meant that all days for about 1 year I gave what I think is optimal light and photoperiod as well (about 8-10 hours of complete darkness every day).

Cheers,
Dav