Catasetinae encountering problems while getting out of dormancy

[proteanorchid]

We've had a month of summer (max temps mostly ~>25C/ 77F) and some of my new catasetinae are taking their time to get out of dormancy.

Unfortunately some red spider mites got from one of my growing catasetums to the new growth of my Monn. Millenium Magic 'Witchcraft'. I've treated it with some alcohol swabs and an insecticide, but not before they inflicted some damage. I don't think the roots are as long as recommended before watering, but the growth does not look very healthy - its yellowing and there was quite a bit of leaf damage. So I was thinking of starting to water it to help it along...
Is this a good idea or should I let the it go without water for long hoping the old pseudobulbs (4 of them) will keep it going?


I also have a Clowesetum Penang Waltz that is small, whose new growth is starting to yellow and I think that needs some water because its old pseudobulbs are quite small. And lastly, this one's medium has shows quite a few salts that have mineralized on the medium, should I remove these or are the roots tough enough to handle it?

Added some photos.
The others are mostly either happily getting out of dormancy or in various stages of being out of sync with with my seasons :P But that's probably for a different post if people want to see that.

[Roberta]

Your mix looks very coarse. A little water near the edge of the pot mgiht help raise humidity in the root zone without getting them "wet" and that might help. But it is still early in the season (late spring, not yet summer) so there is still opportunity for the plants to grow much more.

Once you do start watering, it is going to be a challenge to keep them wet enough...No repotting now, but next winter, you might want to pot them in smaller bark.

One note... spider mites are not insects (they are arachnids) so insecticides won't do much for them. A few drops of dish soap in water might help, or neem oil (you want to smother them...)

[proteanorchid]

Hi Roberta, thanks for the response. Argh sorry, I meant a pesticide that is also meant to take care of spider mites instead of just an insecticide. It has pyrethrum and some other ingredients, I am trying it out for the first time.

Regarding the potting mix - I use a mix of bark and sphagnum moss, and there is more sphagnum lower down in the pot. But this is currently the smallest size/grade of bark (that isn't mixed with other stuff) that I can get. I use a higher ratio of sphagnum moss for my other catasetums.

I'll try increasing the humidity in the root zone without directly watering new the roots.

[estación seca]

Look up posts by isurus79 here on the polyethylene bottle growing method (PET growing.)

Spider mites are in your environment; you will never eliminate them. 70% alcohol, very dilute dish soap and plain tap water sprays control them. I wet all surfaces of all my plants thoroughly every 1-2 weeks during the growing season. This prevents mite outbreaks. For Catasetinae at the start of the growing season, when they shouldn't be watered, I prophylactically sprayed all surfaces of the shoot with 70% alcohol, every 5-7 days.

I routinely

[proteanorchid]

Thanks estación, I'll have to try that. I have mostly been acting against them when I see them rather than pre-emptively. They love the catasetinae and seem to be avoiding the other kinds of orchids (from what I can tell).
Out of curiosity how dilute is the dish soap you use (if you use that)?

And with regards to PET: I've watched many videos from isurus79 and I am trying out PET growing on a couple of plants. Hopefully that goes well.

[estación seca]

I put about 2.5ml of liquid dish soap in 1 liter of water. Insecticidal soaps from garden shops are probably safer for plants than is dish soap, but I don't use it often.

[Roberta]

A caution if you use insecticidal soap... it is a potassium soap, and if your water is hard (lots of calcium), the calcium (combined with soap molecule is fairly insoluble) replaces the potassium (soluble) to make a gunky mess. If you use insecticidal soap and your water has much calcium in it, use RO or DI or distilled water instead of tap water. The advantage of dish soap, it's actually detergent, a synthetic organic molecule, and doesn't have that problem.

[isurus79]

Originally Posted by proteanorchid

We've had a month of summer (max temps mostly ~>25C/ 77F) and some of my new catasetinae are taking their time to get out of dormancy.

Unfortunately some red spider mites got from one of my growing catasetums to the new growth of my Monn. Millenium Magic 'Witchcraft'. I've treated it with some alcohol swabs and an insecticide, but not before they inflicted some damage. I don't think the roots are as long as recommended before watering, but the growth does not look very healthy - its yellowing and there was quite a bit of leaf damage. So I was thinking of starting to water it to help it along...
Is this a good idea or should I let the it go without water for long hoping the old pseudobulbs (4 of them) will keep it going?


I also have a Clowesetum Penang Waltz that is small, whose new growth is starting to yellow and I think that needs some water because its old pseudobulbs are quite small. And lastly, this one's medium has shows quite a few salts that have mineralized on the medium, should I remove these or are the roots tough enough to handle it?

Added some photos.
The others are mostly either happily getting out of dormancy or in various stages of being out of sync with with my seasons :P But that's probably for a different post if people want to see that.

Shoot, these really don't have enough reserves in them to keep going without water. If they were mine, I'd add water on the old roots while trying to avoid the new ones to see if the bulbs will fatten.

If they do fatten, let the plant stay dry again until the new roots are the appropriate length. If they don't fatten using the old roots, you'll have to start watering the new roots, which will have a low rate of success, unfortunately.

It definitely helps to keep the backbulbs fat before the new roots emerge, which can include some sips of water during dormancy. That way, you can keep it totally dry while the new roots form.

[proteanorchid]

Thanks for all the feedback everyone.

@Stephen, thanks for the insight. I'll see whether the back bulbs fatten up and then go for full watering if necessary.

@Roberta I had not considered the interactions of different kinds of insecticidal soaps with tap water. My tap water is relatively soft, but dish soap sounds like less of a headache to try than them.