Winter watering

[estación seca]

An OB member sent me a private message regarding winter watering of Dendrobium Angel Kisses and also Cattleyas. I though the topic is something others would be interested in. The questioner's Angel Kisses had dropped all its leaves.

Dendrobium Angel Kisses has Den. moniliforme in its background. It's from Japan, Korea and China, it gets winter rain, and doesn't drop leaves in the winter. My Angel Kisses didn't drop its leaves during the winter. You might have kept yours too dry. I don't think it will be a problem. When it starts warming up it should grow again and be fine. I would still water Angel Kisses through the winter, letting it get almost dry before watering again. Also realize the thin-leafed Dendrobiums are very susceptible to spider mites, which can cause leaf loss.

I think the "dry winter rest" thing for Dendrobiums is a mistake most of the time. A lot of them may get no winter rain, but have so much winter dew they never get completely dry. Others get no rain and no dew. The care sheets written by people who only look at weather reports say they don't get winter rain, so keep them dry. This is a mistake much of the time because it doesn't account for the dew. Hybrids between wet and dry winter species should get winter watering, but don't need as much. They can get dry between waterings.

Only a few unifoliate Catts have completely dry winters. Among them are dowiana, nobilior, walkeriana and warscewiczii. Tiny seedlings of these still need winter water in cultivation.

Bifoliate Catt species mostly have completely dry winters. In cultivation most people spritz the roots, or splash water on them every 2-4 weeks so they aren't bone-dry for long. Do this on a sunny or warm day if possible. But they should not be moist through the winter.

Most hybrid Catts should be watered through the winter, but they should definitely dry out between waterings. Hybrids with mostly bifoliate ancestry should probably be treated like bifoliate species, and get only occasional winter water, on warmer and sunny days.

[stonedragonfarms]

Great post Estacion, though I believe C. walkeriana is another that is not completely dry over the winter; it too is saturated by nightly fog in it's range. Winter rainfall is non-existent, but like many places in South America, there is a nightly blanket of dense cool fog.
Adam

[Dollythehun]

Could we move the last sections of this post on Catts to the thread Roberta just started? It makes more sense...

[estación seca]

This thread is about all plants and winter watering, not just Cattleyas. I hoped other people would add ideas regarding winter watering.

I started it because most OB members probably grow in areas with cold, dark winters, and winter watering can be a challenge in places like that.

Where I live it is extremely rare to go a week during winter without a warm, sunny day. I don't have to be nearly as careful about watering as would people in the Netherlands, Canada or Wisconsin.

[Dollythehun]

So then, interested members should be asking their questions here...

[stonedragonfarms]

Originally Posted by estación seca

This thread is about all plants and winter watering, not just Cattleyas. I hoped other people would add ideas regarding winter watering.

I started it because most OB members probably grow in areas with cold, dark winters, and winter watering can be a challenge in places like that.

Where I live it is extremely rare to go a week during winter without a warm, sunny day. I don't have to be nearly as careful about watering as would people in the Netherlands, Canada or Wisconsin.

But it also depends on how you're growing...even in the wet PNW, I need to water more often in the house than in the greenhouse...when I lived in the "cold dark north", ie northern Michigan, it was the inverse...

[Roberta]

I truly doubt that one can generalize that bifoliate Catt species need dry winter... "dry" is relative term. I grow quite a few Catt species outside in my temperate (above frost all winter) climate, and they typically get watered even in fairly cold weather about every 4 days (a bit less than twice a week) and thrive and bloom. (C. schilleriana, C. bicolor, C. schofieldiana, C guttata among them) I water less in cold weather because it takes longer to dry out between waterings - and that drying-out is vital for Catts any time of the year (and a lot of other orchid genera as well) . Watering frequency can't be by a formula... it has to be functional, based on what is required under a person's conditions, such that the plants have a chance to dry out. That is going to be different for me and for each of you.

[orion141]

Thanks for the info estacion! Makes one wonder if really cutting out all fertilizer during the winter period is also necessary? Thoughts on that part of the equation?

[orchidsarefun]

So - if you've been able to get your plants to rebloom using your current watering regime in Winter, then you shouldn't be concerned as your plants have adapted to your growing conditions.
Its the plants that haven't bloomed or rebloomed for you that you need to pay attention to. Its this that is the most frustrating for me as often advice is all over the place. I can't bloom an Aussie dendrobium - eventually being told that the plant should have 20+ pseodobulbs. Its that size this year and I'm currently trying out the water only when bulbs are shriveled advice yet again. I'm doing the same with a dendrobium aggregatum that I got in bloom last year. The bottom line may just be that I can't grow these in my conditions and, to save on unnecessary frustration, have to get rid of them.

You can imagine how long it's taken for my Aussie dendrobium to reach that size. Its a big investment in time and care but it's preferable to give it to someone who can bloom these. Maybe out of State.

[Leafmite]

Dendrobium aggregatum--I had one of these for years and could not bloom it. Then someone from my Orchid Society brought one in bloom for the display table. I asked her about the winter rest and she said that she watered it as usual (no fertilizer). I did that the following year and mine bloomed. She had hers in a mix that would dry very quickly and I had mine in the red lava rock and plastic Vanda basket. Mine was under the lights. So, to get this one to bloom, give it good light and water enough so that the pseudobulbs do not get dehydrated.

One cravat...the blooms only last about eight days. Mine was wonderfully fragrant and the flowers are gorgeous but...eight days, once a year. I gave it to someone with more space.