Sure you can water them. You live in the tropics, they will probably all want some water year round. You will have to adapt your watering to your soil and your humid climate, and realise that while many people grow these plants in summer they may grow mostly in winter for you, especially since you have not so much a winter as a dry (or less wet!) season from December to March.

It is natural for Lithops soil to be dry much of the time. They will probably grow best in quite a dense heavy soil, one which holds more water than the one you describe, but left dry for a period between each watering. That works well in hot dry climates, but be cautious until you see how it goes in a hot humid climate. If they appear wrinkled and thirsty then I think you should water them. Make sure that any water is enough to get to the roots which may all be an inch or more deep. In winter the old leaves will naturally get wrinkled but in hot sunny climates they will still like a little water.

I find that Haworthia don't like to be dry for too long or the roots die. Some people in hot climates find that they must be left dry in summer because they go dormant, and they accept that the roots may die at that time. I don't know if or when they might go dormant for you, you don't get the same excessive heat as somewhere like Arizona but you do get very warm nights all summer. In winter I think you should water them regularly, and more than a spray. Again, watch for signs of being thirsty.

Pleiospilos are adapted to water at any time of year but never a lot of water. They can be left dry for long periods between watering or sprayed regularly. They are also likely to go dormant in summer but will certainly be trying to grow in winter. Water lightly when they appear to be growing and try to limit the year-round water so that they always return to a single split-rock state during summer.

Hi Xuan,

Of those you listed, I only grow Haworthias & I water them all year long, no misting, no little sips. I also grow them in crappy soil (they seem to like it), just C&S mix w/ 30-40% perlite or pumice.

Thanks very much for all your inputs, they're very useful for me to nurture these plants.
Last night, for the first time, I put them outside to get the dews... this morning, I checked and they're all wet!!!
Yes, I see some winkles on the mesembs, more before but less now when I regularly mist them. I guess in my climate, they might need water all year round as you described. Perhaps they are 'growing' because I put down a rootless lithop back in September and now it resists my pulling (which could be it has rooted?).
Again, many thanks. I appreciate your advice since I want to grow these so much (I brought them back from the US last August.)
Here's a pic of my plants.

{{gwi:466014}}

Xuan

A picture is worth a thousand words! A little small, so I'm guessing a bit. Haworthia on the right. And on the left too?

Pleiospilos nelii at the bottom and top right. Very slightly overwatered, aim to reduce the number of pairs of leaves slowly over the next 12 months. The plants should produce one new pair of leaves from the centre each year, so you have to allow the oldest pairs to dry up.

Top middle is not a Lithops. Argyroderma, I think? This will be very much a winter grower for you, I think, but should be sprayed year round. It will become dormant in summer but leaving it 100% dry for several months is just likely to kill the roots and abort the flower bud. Again, new leaves will come through soon, let the old ones dry up during spring and summer. Don't water deeply unless the plant is very active and the weather is dry and sunny, it is very prone to splitting its skin when it drinks too much at once. Full sun, I think, even for you, very reflective and will just get soft and rot if you try to grow it in shade.

The Lithops are too tall, especially the two green ones. This is partly from too little light and partly because of too much water. It can be difficult to keep them in full sun when it is very hot but give them as much sun as you can when it is cooler. Again, let the old leaf pairs dry up. They will be growing another pair of leaves now, inside even if you can't see them yet, so it is OK for the old leaves to already be getting a bit soft and wrinkled. Restrict the water in spring until they get back to a single pair of leaves. The Lithops at top left is about how you want them to look.

SnB...many thanks for your detail comments. Actually, the two pleiospilos came to me in that state: having more than one pair of leaves (I bought them at the SF C&S show last July.) Now I'm trying to "help" them reduce the 'unwanted' leaves by not watering them at all. For the two green lithops... they 'looked' tall because when I tried to re-potted them I couldn't bury them enough, but before I un-potted them, they were quite low (just like the one on top left.) The old pair of leaves on all these three are being shrunk considerably and I guess they will soon disappear.
I can see one new pair of leaves coming up from the lithop in the middle right... yeah... I like it so much.
I'll definitely follow your advice here to make the plants happy as long as I can. Many thanks, again.

Xuan