OCCSS Articles |
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Growing Lithops and Other Difficult Mesembs
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Basics
Lithops and other mesembs are a highly desirable group of plants to grow, but the ease of killing them has discouraged many potential
growers from enjoying the full spectrum of this group of plants. The name mesemb is short for the Sub Family Mesembryanthemaceae,
basically Ice Plants, all of which are from South Africa.
Success in growing Lithops and other difficult mesembs is providing the right balance of light, moving air, water and soil. The plants
require a little more attention than some. One must be knowledgeable of the seasonal growing cycle, how much water when; and what the
plant should look like when it's healthy during its yearly cycle.
Seasonal Growing Cycle
Knowledge of the plants seasonal growing cycle is mandatory in keeping mesembs alive and thriving. Basically there are two possible
growing regimes; summer or winter growers. The plants in the summer growing group actually start growing (waking up) in mid spring,
kind of slow down in mid summer, and then have a flourish of growth in early fall. Winter growers wake up in late summer to mid
fall, grow quickly for awhile, slow down in mid winter, then have a flourish of growth in the spring.
The main concern is knowing the plants dormant season, summer growing mesembs don't like being watered during their winter
dormancy, and winter growing plants don't like to be watered in the hot summer or being out in the full sun being cooked
all summer long. But during the spring and fall almost any mesemb can be watered.
Below is a general breakdown of the summer and winter growing mesembs by genus.
Summer Growers:
- Lithops, Dinteranthus (1, 7a)
- Lapidaria, Argyroderma, Tanquana (7a)
- Pleiospolis (5, 6b)
- Faucaria, Schwantesia, Stomatium (6b)
- Frithia (4, 7a)
Winter Growers:
- Conophytum (2, 7a)
- Gibbaeum, Didymaotus, Muiria (3, 4, 6a)
- Cheiridopsis, Cephalophylum, Antimima, Bijlia, Fenestraria (3, 7b)
- Aloinopsis, Nananthus, Titanopsis (4, 5, 6a)
- Mitrophyllum, Monilaria (3, 7b)
- Phylobolus, Spalamanthus (3, 7b)
Key
- New heads grow out of shrived dry remains of old leave pair in spring, general growth during summer, flowering in fall, dormant from mid fall to early spring while resources are transferred to new growth
- Flowering and new growth in fall, general growth during winter, going dormant in early spring.
- A little watering in the fall wake the plants up for winter growth
- Consistent light watering except during dormancy, sensitive roots
- Needs extra water during growing season to maintain fat leaves or roots
- Grows almost all year long
- Short dormancy during mid summer
- Short dormancy during mid winter
- Do not water at all during (maybe a little once in awhile)
- Qinter dormancy, still needs strong light
- Summer dormancy, provide shade, some misting every 14 days
Soil
Mesembs require a well draining soil, which means it dries out quickly. Basically the soil should contain a lot of pumice perlite or
sand. I use a lot of sand, which not everybody agrees with, but works for me. The sand should consist of many sizes of particles, from dust
to 1/8". The basic soil mix is ¼ soil mix to ¾ pumice and sand.
Light and Air
All mesembs require a lot of light and moving air (meaning not humid or stagnant air). High heat is not necessary, but a sunny
exposure is required, some shading is recommended during the summer and heat waves. Best growth is provided by using a green
house, but not necessary, provided that the dormant plants are brought in during the winter rains. Window sills work well.
Watering
All plants need plenty of water during their growing season, but difficult plants are difficult to grow because they are
easy to kill, and most death is caused by too much water at the wrong time of year, or not enough water at the right time.
I water my Lithops and most other summer growers from April to October, usually every 6-14 days. Basically the plants soil should
dry out between watering and the plants should be watched to see if they are too fat, or shrived. Wait a couple extra days between
watering if the plants are too fat and possibly even cracking. The best schedule is wait until a little shriveling is seen, then water.
Winter growers like the same treatment, but from September to May. During the colder parts of the year, soil is slow to dry out, so
lighter watering that only wets the top of the soil is good, so the soil isn't soaked for weeks on end.
Other Tips
I've found that the best info I can suggest to other people trying to grow difficult mesembs is always be on the look out for root
rot. If the plant doesn't seem to be growing during its proper season, check for root rot, a small pull on the plant from
the roots usually does the trick, the plant easily detaches from the rotted area. Most mesembs can be easily re-rooted, usually
its best to cut all the stem off, right up to the last active leave pair. Trying to re-root a clump is risky, its better to cut
the clump up and re-root all the individual heads.
A heat wave in spring, or lack of water, or disturbing winter growing plants may induce early dormancy.
A good time to transplant mesembs is before the growing season, then leave dry until the growing starts, and then water. Another tip,
sprinkle seeds around in pots, some will grow!
This guide for growing mesembs works for me, who lives in Southern California, one of the best growing climates in the world. Many
differences in growing conditions may require varying these guidelines.
By OCCSS Member Craig Fry
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Observations From The Field
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Humidity plays and important part in the health of many cacti and succulents. Although
they have a reputation for growing in arid places, one might be surprised to learn that
nightly fogs actually provide most if not all of the moisture many of these plants need
for growth and seed germination.
Along the coasts of southern Africa and and South America cold ocean currents flow
north from the Antarctic. While the land itself seldom receives rain, fog which forms at
night, condenses on the plants and seeds. Water often runs off the plant bodies bathing .
their shallow roots. In Namibia and South Africa many succulent plants including various
species of Othonna, Cotyledon, Sarcocaulon,and Pelargonium are able to thrive because of
the fog. Likewise along the coast of Chile, a group of cacti called Copiapoa thrive in
the fog zone. As one heads inland from the coastal areas beyond the fog zone, the plants
are unable to grow.
At higher elevations particularly on islands fog also is an important factor. As the moist
ocean air rises it is cooled and fog develops particularly at night. A rich succulent
flora is often found in this zone.
Having visited many such environments I became convinced that a foggy environment in my
growing area might be beneficial to my plants. I purchased a fogger at a local nursery that
I can attach to the end of my hose. On hot days I mist the plants just enough to wet
the leaves and body of my plants. I dont wet the soil. I have observed a remarkable
change in many of my plants. They grow faster, produce more flowers and just appear better.
One must be careful with this procedure as not all cacti in particular like to be wet.
Other growers I know carry around a mist bottle and mist their plants by hand.
You may want to try this and see if your plants dont improve their appearance and health.
By OCCSS Member Gary James
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Potting Soil, Water & Food for the C&OS Grower
One sure fire way to start a vigorous discussion among growers of C&OS (Cactus & Other Succulents)
is to ask "What should I use for potting mix?" This has been the subject of hours of discussion,
hundreds of written words and even a complete issue of the CSSA Journal. Various mixtures
and additives are promoted with almost religious fervor. The only consensus opinion seems
to be that pumice, where available, is the best aggregate to use as a basis for your mix.
Over the last 15 years, I have grown almost exclusively in pumice-based mixtures.
I have used several recipes collected from these discussions and writings, and also experimented
quite a bit, -- sometimes intentionally, and sometimes due to lack of some ingredient. As the
sum of this experience, I can now offer my recipe for success.
I make up quantities of a basic mix from materials that are readily available locally. This mix
provides the most important attributes needed by most succulent plants. It is loose and
friable with lots of available space for air and roots. It drains very quickly, leaving
air space while still retaining enough moisture to reduce frequency of watering without danger
of root hair loss. Ph is usually near neutral at 5.5- 6.5. Here in Orange County, I find it
suitable for both outdoor and greenhouse culture and use it for all but the most specialized or
difficult plants.
My Basic Mix = 5 parts pumice, 2 parts course sand, 3 parts organic material
Pumice is available locally from Orange County Farm Supply in 2 cf. Bags
The sand must be clean and hopefully, of assorted sizes. #12 Silica from a building supply
store also works and, in fact, is what I usually use.
For organic material, there are lots of choices. These are mine, in order of preference:
*Coir (fiberous material from ground up coconut husks)
LGM or Kellogs Leaf Mold
LGM or Kellogs premium planter mix
Supersoil
Composted redwood
*I prefer to use 2 parts Coir and 1 part of any of the next 4 ingrediants but you can use
3 of any of these.
This basic mix is 50% pumice and can be used for almost everything without further modification.
As a plus, it is also easily cut or amended to accommodate special needs. Experimentation is
encouraged. For example:
2 parts basic mix + 1 part pumice = 67% pumice - use this for the higher drainage requirements
of many difficult cactus and more extreme succulents
2 parts basic mix + 2 parts pumice = 75% pumice - use as low organic content mix with super
drainage for mesembs such as Lithops or Conophytums and very hard grown succulents such as
Sarcocaulon or Othonna
1 part basic mix plus 1 part perlite = Very fast draining, low organic mix like above but
retains even less moisture after watering. (Pumice is porous and will retain some water
allowing slower drying of the mix then perlite.) Try this for Pachypodiums but be prepared
to water frequently in the hot months.
1 part basic mix + 1 part organic material = 33% pumice - Good drainage plus higher organic
content for plants like Aloes, Cucurbits (e.g. Momordica) and most tropical or sub-tropicals
requiring constant moisture and more organic content.
The Spice Rack
Growing in pumice based or other soilless mediums requires more attention to the plant's
requirements for food (fertilizer) and trace elements. I keep several things handy to
spice up my basic pumice mixture. You may use any, or all, based on your understanding
or observation of the plant's needs.
Osmacote 270 day formula - time release fertilizer that works well for fast growth in more
organic mixes. Be sure to increase your watering in very hot weather to avoid excess salt
buildup in the potting medium. Flood thoroughly,. wait 20-30 minutes and flood again
to remove salts.
MicroMax Trace elements from the Osmacote people - a good and easy to use micronutrient mix
compounded for nursery use.
Dolomite or Horticultural Lime - add this as needed to adjust the the ph of more acid
(higher organic content) mixes.
Superphospate - good additive to promote root growth when potting bare root
or potting on seedlings
Gypsum - the only way to add usable lime to mix. Good for cactus or succulents that grow
naturally on limestone - just a pinch per pot
Marathon - an expensive but very effective granular systemic pesticide
Watering and Feeding
Now that we all have a few ideas for the planting mix, the next question is,
"When do I water?" Like the potting mix question, there are many opinions.
If you take a survey for any given plant, you will get answers ranging from the reasonable
to the absurd and some that are just plain impractical, like "Look up the weather for
the plant's home area every day and water when it rains there." Although offered in good
faith, such advice doesn't make sense because your plant is here, growing in your mix and weather,
NOT there!! Watering by the calendar (i.e. don't water at all between October and April) is
another suggestion that doesn't allow for the year-to-year or even month-to-month variations
of growth and weather. Like during el NiÑo years!!
Watch and study your plants. If they are in active growth, they need food and water.
Sometimes much more then you would think. This can be as often as every day or two
during very hot dry weather with actively growing plants. When growth is over and dormancy
begins, water and food needs drop drastically, or even cease.
Periodically check the soil moisture. Use a water meter, bamboo skewer or just lift the
pot to see how light it has gotten. When the mix is almost dry, it's time to water. Remember,
that even when fully dormant, most plants will benefit from a small amount of moisture
in the mix to keep fine root hairs from dying. One of the major benefits of the pumice-based
mixes is that it is hard to over-water due to the fast drainage plus the porous nature of
the material which still slows complete drying.
Feeding, as mentioned above, is more important with soilless mixes. For most plants and
growers, the easiest method is to feed at a reduced rate every time you water. If you adopt
this schedule of feeding with every watering, just apply 1/8th to 1/4 th the fertilizer
trength recommended by the manufacturer.
For plant food, I have used all the following with equal results. I suggest changing from time
to time just in case there are trace element differences that could be good, or bad.
Grow More - 15-15-15 (From OC Farm Supply in 5# bags - very economical)
Miracaid Tomato Food -- 18-18-21
Schultz liquid -- 10-15-10
Peters Professional -- 10-30-20
Cactlizer - trace element additive from CSSA seed bank 1 - 2 drops per gallon
Most important of all -- feel free to change or experiment with any of this. The best mix and
culture is the one that works for you and your plants.
Good Growing, Gene Schroeder
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