Hi Ben,

"Easy Lithops" is like "Jumbo Shrimp" - an oxymoron, IMO. I'm sure people who have great success with them would disagree, but I think there are more of us that struggle with them than those who grow them successfully.

With that said, I'll start with your pot. That's a HUGE pot for a Lithop. I grow mine individually in teeny-tiny 1" clay pots. If you wanted to grow a bunch of them in a large pot like that, I suppose you could do so, but Lithops have very small root systems, so I would make sure that the bottom half of the pot was just rock or pumice. I grow mine in coir, but the mix you describe would work.

As for the watering, I water mine in winter about once a month. When they sit on a sunny windowsill, they're going to need SOME water. The key is to watch for the emerging new leaves. At that time, they should not be watered at all as the old leaves are being absorbed and it's getting all it's moisutre and nutrition from them. Wait until the old leaves are completely dried up before even considering giving it water.

Just remember that Lithops really DO seem to thrive on neglect!

Denise in Omaha

L. leslie, L. aucampiae, L. hookeri, L. pseudotruncatella, L. schwantesii, and L. salicola are easy species. Some people consider L. salicola to be the most tolerant of overwatering.

Pot too big? How big is the Lithops? If it looks lost then the pot is bigger than you need. If the Lithops is three or four inches wide then you are doing fine. With the right soil in a clay pot, no pot is really too big. Any pot that is large enough to avoid tipping over is probably big enough. Anything deeper than about four inches in unnecessary, but I've had collections of quite small plants in large planters about six inches deep without problems.

The big vigorous Lithops I listed will grow a taproot several inches long and will develop a decent root system around this in time. They do tend to lose a lot of fine roots when you repot. A Lithops that has been undisturbed for several years will have a large root system and will need far less watering than a newly potted one. Some of the smaller Lithops seem to develop little or no taproot and a thinner fibrous net of roots.

Lithops don't like a soil-less mixture, they like a soil mixture. Peat is a bad thing. Peat plus sharp sand is a worse thing, its a horrible mix that will cake into a solid mass. Pumice is one of the best things you can use. What you want is loam, that is a well-drained garden soil. Literally garden soil if it isn't too clay-ey. Some people use coir, the thing to be careful of is that coir won't hold fertiliser so you need to feed in the water several times a year. If you base your soil on peat then repot every year, every two years at the most. Use about 50% pumice, or a little more if the rest of your soil seems a bit heavy.

Filling the bottom of the pot with something other than the regular soil mix is not helpful. It can be harmful. I don't do it. You can read about perched water tables, air pruning, and capillary action if you like, but half a pot of pumice isn't the right answer to any good questions ;)

A west-facing window is OK. South would be better. I grew Lithops on a southwest window for years, a bit further south than you, and they loved it.

The need for water varies. Big Lithops need incredibly little water, especially when they have established roots. My biggest Lithops seem to be able to suck up water from the air in winter and absolutely don't need any water from about October to May. During summer, the bigger plants can be watered regularly and deeply like a cactus, provided the soil dries out completely between watering. I water big established clumps only three or four times each year. Small ones and seedlings, and any that are recently repotted, will need watering more often, maybe even every month or two in winter. Some of the small tricky species seem to do better with regular light watering or spraying.

Ok, thanks for your help. Well, the thing is that all the soil in my area is like 30% clay, and it gets very hard when dry. I was thinking of using those 'cactus mixes' and mix in some more sharp sand, though it is made up of mostly peat. So, what should I use? How large do L. aucampiae and L. salicola get? Would one in my pot eventually over-grow it? The reason I wanted to use a tall pot was because I heard they grow long taproots, like you said. Would a 2-inch tall bonsai tray work as well? And, where does one get pumice, since I can't seem to find it in Home Depot or Lowes. And the reason I suggested a west window is because there are several large trees that are as tall(er) than my house in the southern direction, while the west is tree-free.

-Ben

Oh sorry. You mentioned pumice so I assumed that you had some. Not easy to find on the east coast. You can try looking for "dry stall", its a fine pumice for horse stalls and is OK. There are mail order sources, but shipping isn't always cheap. Or you can use perlite. Or crushed brick. Or other fired clay products. Or plain old small pieces of stonelike, decomposed granite, pea gravel, or grit.

Its amazing isn't it, that every single book or online article tells you to pot your cactus in "loam" and nobody sells it! Unbelievable! All I can see is don't be suckered in by all the cowboys (that includes you, Schultz) selling peat (plus whatever) as a cactus soil, it just won't work with Lithops. Look around, be creative. You might find that a tree&shrub potting soil is based on loam and not peat. Sandy topsoil for the garden should be suitable but try to get it sterilised. Even your clay garden soil will be fine mixed with an equal amount (or even more) of silver sand, again watch out for weeds and insects. Be careful with the sharp sand, it tends to lock into a rigid structure in pots while softer sands just make a crumbly soil. Don't worry too much about the drainage of this part of the soil because you are going to mix it with an equal quantity of perlite or grit (or pumice) anyway.

The large Lithops species will grow leaf pairs up to a couple of inches across, but they slowly clump up and they can get to be maybe a foot across (takes decades). Perhaps even more eventually but they become difficult and are best broken up. L. salicola clumps up quickly and it often seen in large mounds at shows because it is relatively easy to manage like that where many species would quickly kill themselves.

Ok, thanks again. Now, I was wondering (since I'm not entirely sure myself), but is 'sharp sand' referring to the small grained sand, sort of like beach or play sand? And would the good sand be the larger grained sands, ones often called 'desert sand'? I know that the small grained play sand when mixed with peat and left to dry gets very crumbly, though the larger grained sand does not.

-Ben

Sharp sand is a coarse rough sand. It is used for making things like concrete because the sharp grains can be bonded together strongly. It is useful in small quantities for improving drainage because the grains are large and angular and create air pockets. In larger quantities, the sharp grains lock together and make the soil mix very stiff.

Play sand tends to be very soft (smooth) and fine (small grains) so it is nice to play in. Soft sands are used for things like mortar that need to be workable but don't need to lock together strongly. This type of sand is actually the sort of thing that makes up 80% of a well-drained garden soil called sandy loam, stuff that won't stick together but crumbles. On its own it doesn't make for good cactus soil because the grains are too small and stop water flowing through quickly enough.

Beach sand could be anything, but as a commercial product it tends to be fine soft sand like you imagine on a tropical beach.

I don't add sand to any of my cactus soils although there is sand in the loam that I start with. Especially you don't want to use any sand that is very dusty since the dust just clogs up air gaps that you are trying to create for ther drainage. I add much coarser material like perlite and grit to get the drainage. These are about a quarter inch in size, or a little smaller for seeds and seedlings.

Ok, but I don't think I'll find loam anywhere that is readily available. I just wonder though why this guy says that his plants grow fine in commercial cactus soils with peat. Though, I think most people tend to grow their plants in peat. Any ways, would this be an ok setup?

{{gwi:498076}}

-Ben

Here is a link that might be useful: here

In reading this thread I spotted a magic term---Dry Stall!

Try to find it. Rochester is a big place and it should be available somewhere. Google for sources. Likewise for Turface. My dry stall supplier is currently Agway. Golf course keepers use Turface as do folks who keep scholastic athletic tracks in repair. There is also another product, I suspect it is volcanic origin, that can possibly be obtained from sand/gravel suppliers. It is an ingredient in mortar mixes where weight is a problem. Dark gray in color, pea shaped but possibly slightly larger/smaller depending on the grade, and full of holes. When you see each of these products your planting instincts will tell you precisely how to use them.

I feel all are almost essential in succulent growing, either in pots or in the ground outside, and well worth the search.

(I doubt any of the above substances contain limestone. That's another issue entirely.)

I'm continually amazed at how important inorganic ingredients are in soil mixes--and how, I personally, am getting better and better results by decreasing the organics.

IMHO--sand, try to avoid it unless it is a large grade.

Al

You can grow cacti in pure peat, plenty of plants are grown commercially that way, in combination with sterile conditions and lots of -icide chemicals. You can even grow Lithops in pure peat. You can even grow cacti and Lithops at home in peat-based cactus mixes. I grow many South American species in soils with a significant amount of peat, but for most North American and Andean cacti, and for Lithops, I think you will be very unhappy with the results. If you've ever tried to repot one of those box store cacti grown in pure peat, you'll probably have seen that it cakes into a solid mass, impossible to get wet when its dry and impossible to get dry when its wet, the exact opposite of what you want for a cactus soil.

And keep it simple. The more layers of different stuff you have in your pots the more chance of ending up with a layer of something soggy that will kill your precious babies. When you have the experience to know exactly how well-watered your plants are and how much water remains in the pot, you might want to experiment with layers. Until then, mix up a good soil (and I really encourage you to find something other than peat, especially for Lithops) with plenty of coarse material and use it for the whole pot up to the level of the plant body. You can top that with a coarse gravel if you like, to support the plant and to keep the body dry, although many people don't use gravel so they can see the soil better.

Oh, I see. Thanks a bunch. Well, there is something that I know that I can do, and in that German cactus book that I have, it says to put Lithops in 2/3 sharp (maybe acidic, I'm not sure) sand, and 1/3 clay. I know that I can get pure yellow-ish clay from a creek near by, though that stuff gets hard as a rock when dry. And, if I were to use soil from outside, how should I sterilize it?

-Ben

ive heard that it can be sterilized by putting it in an oven for 30 mins. or even better(and more conveinent for me is the good 'ol microwave