Help please with these orchids

[Brisbanite]

The leaves on the Dendrobium are scaring me, only happened 2 months ago. The buds are starting to form. I did find a few aphids on one bud.
The Oncid. in a month has lost leaves etc. even though it is winter here in Oz. Is this normal? Any advice would be appreciated.

[terra_australis]

No, I don't think that is normal. As far as I am aware Oncids should keep their leaves year round. How low has the temperature been getting in your area overnight? I assume these are being kept in an open outdoor shadehouse?

The kingianum seems to be affected by a fungal disease possibly from condensation sitting on the leaves during cold nights. It doesn't look good I'll admit but it should be ok. I would repot it into a coarse bark mix. I use bark, perlite and volcanic rock in mine to keep it nice and airy. I would then spray it with a fungicide and either move it to a breezier position or bring it inside until the weather warms up.

I would suggest repotting the Oncid into a similar mix. The one you are using looks too soil-like. Remember these plants are both naturally epiphytes/lithophytes so they like a lot of air around their roots.

[Brisbanite]

Dan, the temp. here in Brisb. overnight has been down to 10 deg. when this all happened. They were happy a couple of months ago in previous shadehouse, which only received sun until 1 pm. before moving to an other new outdoor shadehouse, which receives sun all day, with 50% shadecloth. Do you recommend repotting the Dens. which is coming into bud now? Thanks for your advice.

[terra_australis]

Possible that there is a sudden change in temperature for the new shadehouse when the sun goes down which could lead to condensation buildup especially if there isn't much of a breeze. Should be Ok to repot as long as you don't disturb the roots too much. They are generally pretty forgiving.

[pikkumyy]

hey bribanite, i was sure that i had posted a response but i mustn't have come through (obviously). i asked mum and dad about the natrasoap and they couldnt remember (it was 10 years ago).