Plants in the News

Started by David Pilling, May 27, 2022, 01:43:24 PM

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The indoor period should be only for collecting the pistil, the corms should be going to be planted after that. 16:18 23:34


Quote from: David Pilling on November 03, 2022, 11:17:03 AMGrowing stuff indoors is something they like to demonstrate these days. It's often shown on the TV - how to produce salad crops in the centre of big cities. I tried and could not grow saffron crocus to flower here - too dark, cold, whatever. From the text of the article it appears growing saffron in the wild is becoming difficult and that has driven them indoors. That would mean they were not flowering the bulbs indoors one year and then letting them recover in the wild, or bringing in new plants from the wild.
There is a town in England "Saffron Walden" famous for growing Saffron in the middle ages. Not a thing now, but seemingly due to the cost of picking the crop, not climate change.
Hi David. For the last 15 years I have been involved with growing veggies of all sorts (fruiting and leaf) in greenhouses which is what I am referring to, not in my house. (Though the glads were in my backyard aquaponics system in LECA).

I have my reservations about the vertical farms with sole source lighting really working on a commercial scale without venture capital spending, but a proper commercial greenhouse with supplemental lighting can produce single or rotating crops year round. 

To see a successful business look at Gotham Greens. Once a small rooftop greenhouse in Brooklyn NY the company has something like 7-8 very large greenhouses spread over the US.

Potted flowering bulbs grown as cuts or in pots  have been grown in substrates for a really long time. All it takes is time and a market to figure out how to do it. With my upcoming retirement, seems like a great backyard project.

David Pilling

Peter - thanks. Greenhouse might mean natural light and vertical artificial light.

World's largest vertical farm is being built in the UK and it's the size of 96 tennis courts

The world's largest vertical farm is being built to help end the UK's reliance on imported foods.

British retailers already get almost a third of their fresh basil from the team at Jones Food Company (JFC). It is grown, alongside other leafy greens, at Europe's largest vertical farm in Lincolnshire, England.

Diane Whitehead

Oh, that's not what I consider vertical gardening.  The plants are growing on horizontal shelves.

A few years ago there was a lot of true vertical gardening, much of it outside, and popular in one country in particular.  Memory fails here.  I think they were covering walls with fabric pockets.
Diane Whitehead        Victoria, British Columbia, Canada
cool mediterranean climate  warm dry summers, mild wet winters  70 cm rain,   sandy soil

Robin Hansen

The one question I always have about hydroponic and/or vertical gardening is this, and I do not see it addressed. Supposedly, the soil mix and added nutrients replicate whatever the plants need to grow well and produce fruit, i.e. tomatoes. But doesn't terroir or natural native soils impart nutrients and flavor that constructed soil and nutrient mixes do not provide?

It has been years since I've bought tomatoes in a grocery store. They're red, perfect-looking round objects that have no flavor at all. I simply do without until their normal season of fruiting...or use canned tomatoes which certainly taste like real tomatoes.

Is it really worthwhile to grow edible plants in such unnatural conditions, given it seems unlikely to me they can truly provide good quality nutrients and subtle flavors and tastes that an in-ground vegetable or fruit has? I grow ornamental plants of many kinds and they do well for the first two years or so but invariably when planted in native soil, they do much better.

Just curious.
Robin Hansen
President, PBS


I watched the whole videos from China, they were growing the bulbs outside, harvesting just prior and during flowering, then harvesting whole flowers, while sitting down, then someone else was pulling off the stamens.

It was not vertical farming. Basically vertical processing.

Our lettuce and basil beats organic farmed in flavor, useable lettuce (not one leaf is unusable) and the basil has better flavor. Easy to see who sells out at the farmers market and who doesn't. We sell our basil to a former 3 star chef, who now cooks pizza. 

Like it or not, weather happens and outdoor crops fail all over the world. When we have rain, all the lettuce is bad, dirty, and cant be harvested. Lettuce wholesale costs tripled after the last rain. Ours was perfect.

There is a trade off between yield and flavor with tomatoes. There is only so much sugar to go around. Adjusting the EC of the fertilizer water will either increase water content (yield) or decrease water decrease (flavor).

My hobby goal might be to raise saffron in my aquaponics system.

I spent 9 months at Writtle College on sabbatical and we used to go to Saffron Upon Avon all the time!

I hope to learn from all of you, so excuse me if I am being rude.

David Pilling

Robin - here on a small, storm tossed island far North with 70 million people, compromises have to be made. My tomatoes taste better than the ones in the shops, but they're in a greenhouse and grow in peat free compost from the supermarket - best I can do. Anyone from Italy would not rate them.

<insert big argument about interplay of people and nature>


Suddenly wondering that if the Autumn sprouting flowering geophyte forcing for year around is possible, since most geophyte used for forcing should be frozen Spring sprouting ones which are naturally adapted to the frozen winter in the habitat. And if there were difference in the the flavor of fresh saffron and normal ones. (Or there should be 3 version cuisines (Fresh only, normal only, and both) combinations for the customer's experience.)

 The freshly formed replacement corms of saffron (Crocus sativus L.) had no chilling requirements, but sprouting only occurred after a period of after-ripening. Sprouting could be accelerated by a short curing at 30 °C. Shoot growth occurred at any temperature between 1 and 30 °C. The optimal temperature for shoot growth (23-25 °C) proved also optimal for flower initiation. No flower primordia were present in the resting buds. Flower organogenesis occurred during the early summer growth. The optimal temperature for flower emergence (17 °C) was markedly lower than for organogenesis.

 The optimal temperature for flower formation was in the range from 23 to 27 °C, 23 °C temperature being marginally better. To ensure the formation of a maximum number of flowers, the incubation at these temperatures should exceed 50 days, although incubation longer than 150 days resulted in flower abortion. Flower emergence required the transfer of the corms from the conditions of flower formation to a markedly lower temperature (17 °C). Incubation of the corms after lifting at a higher temperature (30 °C), reduced flower initiation and caused the abortion of some of the initiated flowers. No flowers formed in corms incubated at 9 °C. A variable proportion (20–100%) of the corms forced directly at 17 °C without a previous incubation at 23–27 °C formed a single flower. The wide differences in the timing of the phenological stages in different locations we found in this study seemed related to the ambient temperature. Leaf withering was followed shortly by flower initiation, which occurred during late spring or early summer as the rising temperature reached 20 °C. A long hot summer delayed flower emergence which occurred in late autumn as the temperature fell to the range of 15–17 °C.

One month after the completion of flowering the plants were transplanted to the open field, and their CO2 assimilation rates were compared to that of plants coming from corms planted directly in the open. In plants grown at a constant temperature, this parameter, in the range 13-20°C, had no significant effect on the number of sprouts nor that of flowers formed per corm. Flowering occurred earlier at 17°C than at higher and lower temperatures. The flowers formed at 20°C had a wilt aspect. The size of the styles was directly related to temperature and therefore was highest at 20°C. In these plants, however, the styles were difficult to separate from the flower. Growing the plants at a 20/10°C term period hastened flowering and resulted in the formation of normal flowers, but also reduced style size. Growth in the chambers resulted in a 90% reduction of the maximum photosynthetic CO2 fixation as compared with plants grown in the open. This loss was recovered in part (about 50%) several weeks after transferring the plants to the open field.

Judy Glattstein

I have only forced the usual run of spring flowering geophytes - narcissus, tulips, hyacinths, muscari, etc. Once potted up they require a chilling period for rooting. Refrigerator temperatures, that would be 38 to 42 degrees Fahrenheit - are considered suitable.

I remember one year, the New York Botanical Garden had a greenhouse display of Dutch bulbs. As with all their exhibitions it extends for a couple of months, determined by the powers that be rather than horticultural staff. The major problem was not coaxing the bulbs into early bloom but retarding them.

Obviously the Dutch have figured something out, as tulips as cut flowers may be had practically year round.



I think many of the cut flowers we see in markets are from Southern hemisphere locations like Columbia and Kenya
Arnold T.
North East USA

David Pilling

Judy - we often see on UK TV the preparations that go on for the Chelses flower show, there's a whole business of holding flowering bulbs back for it. Big fridges.


While living in a cabin near Fairbanks, Alaska, I got a catalog from a Dutch bulb company suggesting that bulbs could be "forced." I bought some, potted them, and put them under my bed to chill. At times they froze solid: no temperature control in that place. Nevertheless, they grew and flowered (under a grow-light), and I brought them to my university office to delight and amaze all. I especially remember the fragrance of Iris reticulata. That was when I started on the long road to my love of these plants.


In the mid 80's I was working for a large potted plant grower along the west coast. We were just getting into the potted Freesia boom. 
We had weekly plantings of 5000 pots of 4" (3 corms each) and 2000 6" pots (5 or 6 corms each ). 

It was a long time ago, so I am not sure what the season was, but some of the cultivars would pupate and not grow. 

The challenge was not the lack of bulbs but how they responded throughout the seasons, especially after too long or short a chilling period. 

David Pilling

Freesias want to grow in Winter. Here in the UK it is common to find "prepared" Freesias sold in Spring, Heat treated and designed to find the UK Summer, Winter like and grow and flower.

I also had luck sowing seed in early Spring and getting flowers in the same Summer.

I have plenty of Freesias which have reverted to type, growing in Winter, but never flowering.



Hybrid after Polyploidization? (Or find the naturally polyploid population if the species is.)
The role of polyploidization in bulbous flowersJuly 2016NERINE Nerine bowdenii (2n  =  2x  =  22) is the main species of Nerine grown for flower production. The colour range is very limited. Therefore intergeneric crosses are produced using in vitro embryo rescue techniques. The intergeneric hybrid of Nerine bowdenii x Amaryllis belladonna was sterile therefore a fertile autotetraploid was produced (Van Tuyl et al 1992). Backcrosses of N. bowdenii x N. bowdenii x A. belladonna (Fig. 2) were produced and released to the growers.
Since Some species is naturally multi?polyploid?

 Several authors reported variation in ploidy level (3x to 7x) in several species of the genus (Sato 1938; Neto 1948; Naranjo 1969; Lakshmi 1980; Arroyo 1982; Beltrao and Guerra 1990; Zou and Quin 1994). It is interesting to point out that several polyploids previously analysed were considered to be autopolyploids, because they have similar basic bimodal karyotypes to those described in diploid species (Naranjo 1969; Naranjo and Andrada 1975).
Table 1.
Origin, accession numbers and ploidy level of the Hippeastrum species.
Species   Ploidy level   Origin   Kew accession or Herba Nt.
H. machupijchense (Vargas) Hunt   2x   Perú, Cuzco, Machupichu   376-76-03600
H. solandriflorum Herb.   2x   Argentina, Corrientes   301-79-02627
H. aulicum Herb.   2x   Brazil, Santa Catarina   434-79-04428
H. hybrid Sealy   2x   Brazil   344-79-03154
H. argentinum (Pax) Hunz.   2x   Argentina, Catamarca   ATH18258
H. psittacinum (Ker Gawl.) Herb.   2x   Brazil   088-60-08801
H. evansiae (Traub & Nels.) Moore   2x   Bolivia   302-79-02858
H. tucumanum Holmb.   2x   Argentina, Tucumán   361-75-03430
H. parodii Hunz. & Coc.   2x   Argentina, Corrientes, Três Cerros   400-76-03888
H. correiense (Bury) Worsley   2x   Brazil, Sao Paulo   419-72-03854
H. rutilum (Ker Gawl.) Herb.   2x   Brazil   501-66-50111
H. morelianum (Lamaire) Traub   2x   Brazil, Sao Paulo, Serra do Mar   419-72-03853
H. puniceum (Lamb.) Kuntze   3x   Guyana, Mt Roraina, Kako   236-80-02247
H. reginae (L.) Herb.   4x   Peru, Cuzco, Marcapata   408-53-40803
H. rutilum (Ker Gawl.) Herb.   4x   Brazil   006-69-16919
H. starkii (Nels. & Traub) Moore   4x   Bolivia   487-67-48702
H. blossfeldiae (Traub & Doran) Vam Scheepen   4x   Brazil, Sao Paulo   139-74-01555
H. scopulorum Baker   5x   Bolivia, La Paz   037-72-00389
H. rutilum (Ker Gawl.) Herb.   5x   Brazil, Pelotas   396-70-03892
H. cybister (Herb.) Benth. ex Baker   5x   Brazil   418-72-09675
H. puniceum (Lamb.) Kuntze   6x   Brazil, Sao Paulo, Araras   277-78-030023


Similarly, in the genus Hippeastrum, apart from diploids (2n = 2x = 22), there are triploids (2n = 3x = 33) in H. puniceum (from Guyana); tetraploids (2n = 4x = 44) in H. reginae, H. starkii and H. blossfeldiae; pentaploids (2n = 5x = 55) in H. scopulorum and H. cybister; and hexaploids (2n = 6x = 66) in H. puniceum (from Brazil) [65,75,76]. A number of Hippeastrum species are euploids, including H. forgeti (2n = 23) and H. iguazuanum (2n = 24), and aneuploids—H. blumenavia (2n = 20) [75,77,78].