Winter watering and fertilising for struggling bulbophyllums

[AussieGrower123]

I've got a small collection of bulbophyllums and I'm a bit unsure of what to do with them coming into winter regarding watering and fertilising. Some are recent additions and so I've not seen how they behave in colder weather before. I've been watering and fertilising more frequently over the past months and some seem quite happy with the treatment. These plants are smallish - much bigger that tube stock but under about 20cm across. Do bulbophyllums need resting over winter? If yes, how frequently would you water and fertilise?

On top of that, some are struggling - the bulbo ambrosia seems generally unhappy (no new growth and the roots look tired and brown) and I'm having significant trouble trying to plump up the bulbs on the bulbo guedoreii - I've been trying to coddle both with weak fertiliser each watering (about every one to three days depending on how moist they seem) but they're just not taking the hint. The guedoreii had a new growth recently but that's gone dark and died off. Not sure what I'm doing wrong with these - my bulbo scaberulum and bulbo roxburghii get the same light and even less water (though they are larger plants) and they're flourishing (seriously - the roxburghii just put up about 8 new leaves and grew by maybe a half what it was before).

I've also got some tiny bulbos that look even sadder - they're in what appears to be thick moss and I suspect they're getting too much moisture - which is odd, as the seller I bought them from said they were several years old and flowered already, implying they'd been liking that medium in the past.

Any suggestions for what can be done to encourage/ rescue these plants would be much appreciated!

[Ray]

Originally Posted by AussieGrower123

Any suggestions for what can be done to encourage/ rescue these plants would be much appreciated!

Stop feeding them. Unless they have received no nutrition for months and months, fertilizer will not cure any problem.

Most bulbo's I am familiar with like it really hot, and really dislike the combination of cold and wet roots.

[estación seca]

How cold is cold? Most Bulbos need daily watering during their growing season, which is to say they need to stay very wet, and they are harmed by drying out completely once. As Ray mentioned, they don't like cold weather at all.

[isurus79]

Any pics?

[AussieGrower123]

Hi again,

Thanks for the responses! Here's some pics that will hopefully illustrate better what I've been trying to describe.

The first two pics (with the long thin bulbs) are of my very sad bulb. ambrosia. I've been trying to keep it really moist through frequent fertilising (about every 1 - 3 days) but it's just not perking up. Down here in Australia, we're at the end of the first month of winter... perhaps that's a factor? Probably not - this little plant has been declining for much longer than that.

The second two are of my bulb. guedoreii (that's what it said on the label but I've not found any mention of that name online and the plant has never flowered for me to know what it looks like). When I got this, it was quite withered. Having raised a couple of happy bulbos before, I thought I'd be able to perk this new one up - the bulbs eventually plumped up (after months and months) and it even put out a new shoot but now it's withered again and the new growth has died off. I've been keeping it moist with weak (I think) fertiliser but those bulbs are shrinking. Is this just normal winter behaviour or am I doing something very wrong here?

At the other end of the spectrum, my bulb. roxburghii has a number of small new leaves... and we're heading for midwinter. I've been keeping it moist with that fertiliser and it seems to love the treatment but I'm wondering if it's supposed to be settling down instead of growing at this time of year. Baffling.

Anyway, your advice (particularly on reviving those unhappy bulbos) would be very appreciated!

AussieGrower.

[estación seca]

They look as though they aren't getting enough water. Don't use fertilizer on sick plants. An American bulbo grower with lots of awards, Bill Thoms, grows his in long-fiber sphagnum moss. He waters heavily, every day of the year, so the plants are soaking wet.

What is the temperature range in your growing area?

[isurus79]

I also notice there is nothing holding the plant to the media. The best way to ensure roots don't grow is having the plant regularly wiggle from wind and watering. The root tips get damaged and stop growing. I'd repot in long fiber spag and make sure the plants are well secured.