Nerine sarniensis culture from Peter Smithers

Mary Sue Ittner
Thu, 02 Sep 2010 08:53:37 PDT

One of the wonderful things about participating in bulb lists is that 
you find out there is not one way to grow bulbs and that they can 
often be very adaptable. Having said that,  I saved advice Sir Peter 
Smithers gave on growing these to help people have success with them 
and am including it below. He was considered "the expert" on growing 
them at one time. It actually speaks to some of the issues we have 
been discussing.

Mary Sue

>1. Climate.   In a temperate climate these plants flower from late 
>September to December.   They produce six leaves from early October 
>to January.   From then until May when they go to rest, they remain 
>green and are presumably doing important things 
>underground.   During the resting period from May to September in 
>nature they enjoy diminishing levels of water from deep in the 
>ground but get no rain at all.    As in nature they grow at quite 
>high altitudes there is a sharp day/night temperature 
>differential.   Flowering is triggered by the drop in temperature in 
>early autumn, possibly by the steep drop in night temperature.
>2. From the foregoing it follows that they can not be grown as a 
>commercial crop in the open as is the case with N.bowdenii in a 
>climate which has either substantial winter frost or substantial summer rain.
>3. Under  glass they are easy enough provided that the above 
>requirements are respected, but it is a timetable which does not 
>suit the management of a mixed collection of plants, so that if they 
>are to be really successful they need a house to themselves. In a 
>mixed collection of plants they will have to receive individual 
>attention,  being watered and moved into dry quarters or a low 
>temperature area as necessary, but they are so magnificent in bloom 
>that they are worth the little extra attention if it can be given.
>4. Growth cycle in cultivation. They are easily moved as dry bulbs, 
>preferably at the beginning of the resting season in May, because at 
>that time though the foliage is gone there is a new flush of root 
>growth subsisting in nature on residual moisture deep in the soil. 
>So on repotting they should be watered by immersion once and then 
>given only a little water once every couple of weeks until flower 
>spikes appear.  In this way they will immediately form a new set of 
>roots in the new pot. Watering should be plentiful  from flowering 
>until all six leaves are finished in the New Year, when it should be 
>given in moderation until it is witheld as the leaves turn yellow. 
>These are NOT plants which have 'do not disturb' written all over 
>them.  They transplant and repot without difficulty. However their 
>growth cycle is a long one, the flower being formed within the bulb 
>a year previous to the cycle in which it will finally emerge as a flower spike.
>5. Temperatures etc. While in growth a range of night temperatures 
>of about 10C to 15C is ideal. The plants will survive temperatures 
>down to slightly above freezing without harm.   Higher night 
>temperatures are definitely harmful in the growing period, but 
>during the resting period in summer it does not matter how hot the 
>plants get though roasting  is not necessary. Full sunlight is 
>essential during the growing period and so is the maximum amount of 
>ventilation compatible with the temperature range.
>5. Materials.   I preferred plastc pots which were easier to control 
>so far as moisture is concerned. Deep pots are preferable, and not 
>too large. Compost is a matter of controversy.   I was never wholly 
>satisfied with mine.   Well drained, with about 25% peat, 25% sharp 
>sand and good garden soil for the rest.   My P/h was slightly acid to neutral.
>6. Pests and diseases.   Heavy fertilisation releases the virus 
>which is dormant in these plants. As I did not fertilise at all, I 
>only once or twice saw virus in any of some thousands of plants. 
>Research in the wild showed that these plants grow in nature in some 
>of the world's poorest soils. Attempts to push them for rapid 
>maturity from seed or cuttage and largest size flower heads or two 
>spikes per bulb resulted in the near collapse of one large 
>commercial operation from virus. I only once lost a bulb from insect 
>attack when mealybug somehow got inside a bulb and my efforts to 
>destroy it destroyed the bulb as well!   Insects are not a problem 
>with these plants. My greenhouse would never have passed a 
>phytosanitary inspecton because it was also used for certain things 
>compatible with the Nerines, i.e. a winter store for 
>Citrus:   Passiflora edulis, Hoya and some scandent Epiphyllums 
>which housed several enemies which did not trouble the Nerines.
>7. Performance. I was satisfied if 85% of flowering size bulbs 
>bloomed.  Possibly a better cultivator could have improved on 
>that.   I was neverwholly satisfied with my culture.

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