Mix drying too fast - Orchid Board

Benno · #1 10-23-2018, 10:20 AM

I've repotted my phals about 3 times in as many weeks trying to get the right mix lol. The first couple of times I had not very good store bought mixes that had very non uniform particle sizes and stayed too wet.

I have now got medium sized Kiwi bark (8-20mm, I'd say the average is about 10mm) which I've mixed 4:1 with simioar sized charcoal and then added a small amount of nz sphag.. the kiwi bark is excellent stuff - my pots drain very fast indeed, but now they are drying too fast! They are quite light after watering or soaking for 30 minutes. Today I had to water 24 hours after the previous water, with overnight temps of 19C and daily max of 28C (66-82F), humidity ranged from 91% to 50% over that temp range. The orchids are in clear plastic orchid pots and I have drilled a few 3mm holes around the lower circumference for slightly better ventilation.

What do you suggest I do to extend the watering period to 3 days or so for somewhat lower maintenance plants? It often gets to low 30C's here in summer. Add more sphag to the existing mix? Would perlite help or make no difference? I've just tried soaking some 3mm perlite to experiment and it didn't really seem to hold much water.

Thoughts welcome...

Roberta · #2 10-23-2018, 12:03 PM

If you can manage the extra watering, I would say "GREAT". The plants want moist air, not "wet", and it sounds like that is what you have. In time, the bark will become a bit more retentive. With that mix you can't ever over-water. In summer, you could even put the pots into saucers with about 1 cm of water, it will get wicked up over the course of the day.

Benno · #3 10-23-2018, 05:24 PM

Yeah you have to be careful what you wish for sometimes

I'd like to stretch it to a few days so I can be away without having to get someone to water them. Hopefully as you say, the bark will hold more water given more time. I'll experiment with the saucer idea.

Roberta · #4 10-23-2018, 05:30 PM

Quote:

Originally Posted by Benno

Yeah you have to be careful what you wish for sometimes

I'd like to stretch it to a few days so I can be away without having to get someone to water them. Hopefully as you say, the bark will hold more water given more time. I'll experiment with the saucer idea.

A trick from a friend of mine who travels a lot (and has lots of Phals) ... take a wide shoelace (cm wide or more). Put one end in a container of water. Put the other end in your orchid pot. The shoelace wicks water from the "reservoir" and provides constant, gentle dampness to the orchid.

camille1585 · #5 10-24-2018, 03:57 AM

All my orchids sit in saucers (slightly larger than the pot) to catch drips after watering, and in the summer I fill the saucers, and the water takes a day or so to be taken up or evaporated. That way I can water every 4-5 days when it's really hot (which is anything over 26-27C here) instead of every 2-3 days. When I go on holiday in the summer, I draw the curtains, water the plants well, then fill the saucers. I can go safely go away for 2 weeks that way.

Ray · #6 10-24-2018, 09:18 AM

Benno - before using the bark, pour very hot or boiling water over it, as that causes it to swell, allowing it to absorb more.

Rather than repotting again, water the pots heavily, wait 30 minutes and do so again., and maybe even a second delay and third watering. After that, it will have absorbed enough water and "opened up" that it will take the watering better in the future.