At 51° N.L. .. How my Lithops year moves on.
Let's start the cycle right after the flowering, which on average, is my early month of October, typically the first half of October, although with the present climate change, the tendency seems to indicate later "moisturising" may be in order. So, sometimes stretching somewhat later, depending on the weather.
My growing concept is almost strictly following the explanation as given by Dr Geyer and which I mention under the "Habitat" chapter.
It involves passive winter growth while the leaves change, sparingly misting in spring near the end of that transition, a summer drought and increasing watering near the end of my summer with a water stop near the end of flowering. All subject to adjustments depending on local weather conditions.
I do *not* really water in the Spring as there is no stringent evidence that several Lithops populations do get any water in that period of the year.
Always remember that I cultivate my Lithops in a small greenhouse outside.
So let's discuss this in a bit more detail starting near the end of the "active growing" season.
In general I stop watering completely, in terms of pouring water over the plants and/or the soil, right after or even during the end of the flowering.
Depending on the weather, temperatures and sunshine, they may get some light misting if they still show some growth intention but my season is very tricky at this time of the year, so better safe than sorry. This means a light water spraying can be done at about 50 cm over the plants, NOT providing a shower! I cannot afford it to have wet plants for a long time at this time of the year! I use forced ventilation to get the plants dry as fast as possible due to high air humidity. Temperatures will/may quickly drop now, we talk about 16°C to an occasionally 20°C during the day, nights may drop to 8-9°C, but 12-13°C daytime with low 3°C at night may be possible now, including some light frosts at soil level or even not as much as at "soil level", it may happen.
From now on they will reside in a quickly cooling down greenhouse, and from November on they will get less light because the greenhouse needs to be insulated with two layers of bubble wrap to survive the possible freezes in our winter. Greenhouse is kept at a minimum of +5°C but depending on the outside temperature (and heating hysteresis) temps may drop to just under 4.5°C before ramping up. If we get unexpected "lows" before I start the heating system, I've seen temps as low as 3.6°C with no damage to the plants. Air humidity remains fairly high here and it is not uncommon to see it above 80% RH and in dark, gloomy and chilly periods, even well above 90% RH. However, a distinctive additional trend that I observe is that the RH values seem to drop, probably also due to the changing climate and our regions become much dryer. (We start to lack rain! go imagine!)
Unfortunately, this cuts down on the "late" flowerers as I see their buds develop but I never see their flowers. Heating up the greenhouse and providing artificial light at a sufficiently high level is just not practical from an "economical" point of view because "energy" is extremely expensive over here. (I don't run a commercial facility!)
Because of good growth and care in early Autumn all plants will now be plump and water turgid to start their winter and have a go at the change of leaves. In general, by half November they will mostly be one month without water but due to the copious watering in the growing period, they are well armed to face winter "rest".
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| View November 14th 2018 |
Now my Lithops plants will not get any water anymore till the end of the shedding of their old leaves. Once again, depending on weather and species, this may take as long as mid-April, even end of May or even beginning of June for some "lazy" ones. This is very strongly influenced by our weather. This will imply serious wrinkling after 2-3 months, and more, because the old leaves are slowly sucked dry by the new ones. This is NOT, REPEAT 'NOT', a sign that the plants need water! Watering during that time will/may plump up old leaves again producing ugly towering Lithops. Temperatures ramp up again in March although we may still suffer night frosts. Dangerous part of the year as it may already be very hot in the greenhouse, especially before the bubble wrap is removed.
Starting from mid-April I may be forced to lightly mist them again to mimic the dew. Once again "lightly mist", NO shower. This is also because it can already be very warm in April, especially with the climate change. Mostly the winter bubble wrap is removed mid-April so they may get a full sun blast. I counter excessive sunshine by using a special windows coating to block excess light. Day time temps get up to 30+°C in the greenhouse now, night may stay around 12-16°C.
It is also near the end of the moulting that I transplant Lithops that may need a larger pot. For me and here, it is the most favorable period of the year as it kind of, has the best conditions for swift regrowth. This does not mean that I'm afraid of transplanting at other times of the year, but that would only be in an "emergency" setting. I avoid it. This is also why I almost completely avoid buying plants starting near the end of my month of September because of the terrific season shut down. If I buy some then I need to "pamper" them to toughen up before winter.
Additional (and for me) important, note:
In a lot of references advice can be found to water Lithops "in the spring" on a fairly regular basis (every 10 days?). I think this can only be done in very warm climates where leaves change is very fast. I think that this "rule" has been put forward by people living in a hot climate and then it has been promoted to "general cultivation rule" irrespective anything. Here I cannot do this, I would just revive the old shrinking leaves and generating towering Lithops.
Besides, there are several habitat climate graphs that clearly show that in certain habitats there is NO Spring rain as such, at least, not at the level of "pouring rain" (which may not exclude an occasional shower, I guess)
My observations, however, are that at some point of the spring "drought" and when we get very good weather, the change of leaves seems to stall (lack of minimal humidity?). Some more heavy misting seems to solve this problem by forcing the plants to resume the moulting.
In a similar concept, I cannot "water" ie really pouring water on the soil, here because the period of time between the end of moulting and the first very warm days, may be extremely short. I have had nasty situations where wet soil helped cooking Lithops "en masse" when temperatures were suddenly rising higher than could be expected.
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| End of May |
Here is another status example of young plants, L. dorotheae, all sown in 2016 and pictured on April 29th 2019. They have only been superficially misted about 3x in the last 4 weeks because it was exceptionally hot here (35+°C in the greenhouse, door and all vents open!)
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During the hot summer months, my only concern is to keep acquired water turgidity almost unchanged despite the heat in the greenhouse. I tend to keep on a real "drought" status. These last years I noticed that the temperatures may run as high as 50°C or even more on several days (40 to 45°C in the shadow, Heath waves in 2019 poked the temp up to 47.5°C in the shadow). Then I use additional shading to prevent sunburn together with strong, forced air movement (large fans). Misting may be somewhat more intense and I use capillary mats on the bottoms of the trays that allow me to give a largely controlled amount of moisture "from below" (I deliberately do NOT call it "watering" as it really isn't ...). But when it is so hot , then it is risky business IMHO to play with water. I've seen really "cooked" Lithops more than I care for and it may happen within hours!!
Strangely enough, despite the rather dry summer conditions, the early flowerers really don't mind following their natural way. Like L pseudotruncatella species always flowering end of June or beginning July (here), later followed by gracilidelineata species. All the rest flowers end of September and October.
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| Pseudotruncatella July 1st 2018 |
As my rule I give a first superficial watering in the third week of August unless it is still piping hot in the greenhouse (like 2019). Just to awake the plants and make them aware that the growing season is near .. as if they don't sense this by all the changing climatological triggers, like short day length, sun elevation in the sky, higher air moisture .. etc.
A first deep watering comes in the first week of September with a real drench if they have responded to the previous superficial watering in August. It makes no sense to drown them in September if they did not make new roots in August. From then on they may get between 3 to 5 drenches till the end of the watering period, and then the circle is closed. The first buds, followed by flowers, appearing by early or mid September.
and that mostly concludes the annual life cycle here ....
Followed by the flowering peak in October.
and that mostly concludes the annual life cycle here ....
Followed by the flowering peak in October.
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| October 4th 2018 |
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| October 12th 2019 |