Nerine sarniensis '09

[mark smyth]

I assumed it takes heat in summer to produce a flower in the bulbs

Here is Purple Robe from the other side.

Wolsey is open today.

I think my garden centre Nerine pudica, bought as bulbs in a bag a few years ago and flowering soon for the first time, might be sarniensis. The buds are white with a dark stripe.

[johnw]

I assumed it takes heat in summer to produce a flower in the bulbs

Here is Purple Robe from the other side.

Wolsey is open today.

I think my garden centre Nerine pudica, bought as bulbs in a bag a few years ago and flowering soon for the first time, might be sarniensis. The buds are white with a dark stripe.

See PaulT's and Alessandro's pix of N. pudica, you may have the correct item.

I don't see how a leafless bulb in summer could make a flower bud while dormant.

johnw

[mark smyth]

I was told the bulbs need to be baked in the sun to trigger bud development. Isn't this what happens with Sternbergia?

I Googled pudica and found white flowers, white with a line and a stunning purple tipped one
http://www.flickr.com/photos/8073338@N08/2370697488/

[johnw]

I was told the bulbs need to be baked in the sun to trigger bud development. Isn't this what happens with Sternbergia?

You're asking a fine one, I have never flowered a Sternbergia in my life.  Can't provide enough heat even in my greenhouse.  And Lycoris radiata bought in 1974, well I am still waiting.

johnw

[johnw]

I Googled pudica and found white flowers, white with a line and a stunning purple tipped one
http://www.flickr.com/photos/8073338@N08/2370697488/

Oh my, isn't that a beauty!

I wonder where she took the picture.  Said to be rare so I wonder.  Grow Nerines by G. Duncan says of pudica "perianth segments almost flat with very little waviness...pink central keel visible on both surfaces, or restricted to just the lower surface....leaves emerge soon after the flowers open...3-6 flowered umbel...slender glabrous peduncle up to 460mm long...perianth segments vary from 25-32 long, and usually overlap each other by up to have their length, a character not encountered in any other Nerine".  Flowers look rather small in the book. The flowers look more substantial in Colour Encyclopaedia of Cape Bulbs but the leaves are said to be 3mm wide, look like hair in the photo if those are the leaves.

johnw - beastly cold day here, 11c, raining, miserable and thunder, now clearing in the west and a frost warning inland.

[mark smyth]

Here is pudica in bud. Also Atlanta and Wolsey. Wolsey should be an intense deep red but my camera cant do reds very well

[johnw]

True beauties Mark.  Wolsley looks like a great red.  The pudica looks right, what about leaf measurements.

Pulled about a dozen bulbs with buds today and hoping it's not a bust this year.

Always worthwhile to do a flower count on each stem every year.

johnw

[mark smyth]

http://www.rhs.org.uk/Plants/plant_groups/NerineStudyDay.pdf pages 41,42,43

The first unusual feature seen in both Nerine bowdenii and N.sarniensis, and possibly other species, is the presence of two flower initials (buds), of differing ages, within the bulb at any given time (Sytsema, 1982). As far as is known this does not occur in Northern Hemisphere bulbs such as daffodil or tulip which lay down flower initials during the summer preceding flowering. Nerine, on the other hand, initiates a bud each growing season which requires two growing seasons to bloom hence a mature bulb will normally contain one large, outer, bud and one small, inner one. Towards the end of this talk I will suggest some reasons as to why this unusual behaviour may have evolved. We learn from the Dutch studies that nerines produce several leaves and a single flower initial (in the case of N. flexuosa there may be several) each year. Nerine bowdenii initiates at the end of its growth phase, i.e. mid‐late summer, whilst, N. sarniensis initiates at the beginning of its growing season, namely the autumn. Interestingly, Graham Dncan (Duncan, 2002) states that in South Africa N. sarniensis initiates at the end of its growth period. Can there be a difference between its behaviour in the northern and southern hemispheres? Clearly, this is something needing to be followed up since conditions and culture applied at the time of floral initiation could be of some importance. Now, let us consider the conditions required during the two years during which the various flower parts develop from the apex to the emerging bud, as this is when bud abortion can occur if conditions are unfavourable (see Fig.2). There is, in fact, plenty of evidence that N. bowdenii will abort the smaller of its two flower initials if the temperatures are too high in the first year of its two year ‘gestation’. Field grown bulbs which have initiated under cool, field, conditions perform well in their first year under glass but a second year under glass will see many failing to bloom. The critical temperature has been found to be about 25 °C (see Fig.3). Dissections of buds experiencing high temperatures show that they do not develop properly and subsequently die. For this reason N. bowdenii is not grown continuously under glass but ‘rested’ in open ground before reuse. High temperatures also increase the risk of basal rot (Fusarium). It is now generally accepted that N. bowdenii should not be kept too hot and dry in summer when in leaf. I understand that N. bowdenii performs badly in Israel and I have found some hot sandy soils in the Isles of Scilly unsuitable. So,ignore the suggestion to plant at the base of a south‐facing wall – an open site or even a lightly shaded one is preferable. Bear in mind that N. bowdenii is a native of the summer rainfall area of the Eastern Cape and the bulbs will often be shaded by vegetation. Our Amaryllid Journal of November 199933 raised the fascinating point that in South Africa a site near a south‐facing wall is preferred.Surely this advice has not been blindly followed here! So much for N. bowdenii.

[johnw]

Mark - So it would seem at this time of year we are just entering the critical period for flower bud formation.  And that those internal buds can abort if summer temps are not within the range suggested or the bulbs got too dry. Right?  We may have quite the puzzle deciding if the mix, the early autumn or the rest was the problem!

johnw

[mark smyth]

What about N. sarniensis, the Guernsey lily? It appears that here also there have been misunderstandings over its preferred treatment in summer. Hellyer (1948) stated, “In May, as foliage dies down, stand on shelf near the glass and cut down water until absolutely dry.” Today, few nerine growers would agree with this and the alternative of placing pots under the bench or outdoors would also be avoided. Dutch work suggests an optimum mean summer temperature in the range 17—21 °C, whilst Warrington et al. (1989) in New Zealand had excellent results with ‘Salmon Supreme’ kept at 22 °C when amazingly 42 % of the bulbs produced second stems, something that seldom happens in the UK. Warrington et al. Compared constant 14 °C, 22 °C and 30 °C and state that 22 °C was by far the most successful and is close to the mid‐summer average of the Cape of South Africa. Both Dutch and New Zealand workers agree that both low temperatures (approaching 14 °C) and high temperatures (30 °C) in summer reduce flowering. These data are summarized in Table 1, below. At the Study Day Graham Duncan confirmed that Cape temperatures do at times exceed 30 °C, but states in his book that, in their native habitat, montane species such as N. sarniensis enjoy morning sun and afternoon shade. We also understand that the mountains of the Cape are often attended by mist and occasional drizzle during the summer. So, I personally do not clean up dead foliage until August and place newspaper over pots exposed to direct sun in the hottest part of the summer. My plants, though dormant, receive an occasional damping over and those on shelves and staging have capilliary matting beneath the pots. Winter temperatures down to 4 °C are said to be tolerated by N. sarniensis but freezing must beavoided at all costs. There is evidence that the optimum temperature after flowering and during susequent winter growth is about 14C

[johnw]

Understood, but the plants tested were most likely given the best soil mix, fertilizer regime and otherwise optimum conditions as worked out by highly experienced producers.

johnw

[mark smyth]

The last line about sarniensis is something mine never get and could be why many of mine dont produce flowers every year. Mine are in an unheated green house and take what ever the weather does. I couldnt afford to hear my Nerine bulbs to 14C all winter

Anyone else on the forum growing N. sarniensis?

[mark smyth]

My pudica has well developed leaves

[mark smyth]

N. sarniensis
autumn 17–21 °C Falling
winter 9 –13 °C Minimum 4°C
spring 13 °C rising to 21°C
summer 21–22 °C Avoid excessive heat, cold or wetness in summer

[johnw]

My pudica has well developed leaves

Duncan says 2-5mm wide, Cape Bulbs says 3mm wide.

johnw