CA1091950A

CA1091950A - Flower preservation

Info

Publication number: CA1091950A
Application number: CA280,683A
Authority: CA
Inventors: Cesar Romero-Sierra; John C. Webb
Original assignee: Queens University at Kingston
Current assignee: Queens University at Kingston
Priority date: 1977-06-16
Filing date: 1977-06-16
Publication date: 1980-12-23
Also published as: JPS548026A; GB2000012A; DE2826461A1; FR2394245A1; JPS5827761B2; GB2000012B

Abstract

ABSTRACT
A process for preserving substantially any variety of flower while retaining the natural colours thereof, in which the flower is immersed in a composition comprising: at least one dehydrating alcohol, an alkaline phosphate, a carboxylic acid, a urea-containing compound, an alkaline citrate, a silicone fluid, and optionally a silicone resin, phenol, an alkaline formaldehyde sulfoxylate, aluminum or magnesium sulphate and cupric or other transitional metal sulphate for sufficient time to dehydrate the flower. Following immersion the flower is dried and, if desired coated with a silicone resin.

Description

This appllcation relates generally to the preservation of flowers and more particularly to a process and novel co~position of matter for the preservation of the natural colours of flowers, and to the preserved flower product.
The preservation of flowers for museum specimens, for educa-tional purposes in the natural sciences and elsewhere, for decorative and ornamental use, for displays and the like has been practised for many years and many processes for such preservation have been described ~,~r~ in the literature. Attention is particularly directed to U.S. Patents J~

2,65~,929; 2,658,836 and 2,698,809 to Fessenden and U.S. Patent iL~q-r4-~
to Malecki and to "Handbook of Plastic Embedding" E.L. Lutz (1969) p.
60~73 for descriptions of the processes employed heretofore for the preservatlon of flowers and other plant and anlmal tissues. S1~ch prior art processes are not, however, entirely satisfactory because the delicate natural colours of the flowers tend to fade relatively qulckly and the flowers are also extremely brittle, fragile and highly suscepti-ble to damage in extremes of temperature or humidity so that special handling and storage techniques are necessary. Without such special techniques the natural beauty of the flowers is quickly lost and the flowers lose their usefulness for display or educational purposes.
Indeed storage in sealed bells or embedding in plastic have heretofore been the only practical methods of storage and handling. Further, in order to treat differently coloured flowers according to the prior art it has been found necessary to use a variety of treatment solutions as no single treatment solut:Lon, which is suitable for all colours of flowers, has evolved.
It is, therefore, an object of the present invention to provide a process and a single composition of matter for the preservation of flowers which is suitable Eor use with substantially all colours and varieties of flowers and which will result in naturally coloured flowers which retain the freshness, flexibility and beauty for relatively long periods of time without the necessity o special handling ancl storage ~l~9~9t5~

techniques.
By one aspect of this invention there is provided an essentially ~ater-free composition, for the single step preservation of fresh, naturally coloured blooms comprising an effective amount of at least one dehydrating alcohol, a urea-containing compound, a carboxylic acid, and an alkaline citrate, and at least one of: aluminum or magnesium sulphate, a transitional metal sulphate, and an alkaline formaldehyde sulfoxylate, and zero to an effective amount of at least one of a silicone fluid and a sili-cone resin and which also contains a sufficient quantity of at least one compound of the group consisting of an alkaline phosphate and phenol so as to ensure said composition has a pH in the range 5 to 7.
Thus by a preferred aspect of this invention there is provided an essentially water-free composition for the preservation of fresh, naturally coloured blooms, comprising in amounts per litre:
700 - 900 ml. of at least one dehydrating alcohol 6 - 8 g. alkaline phosphate 2 - 3 g. alkaline formaldehyde sulfoxylate 2.5 - 7.5 g. citric acid 10 - 20 g. thiourea 2.5 - 10 g. aluminum sulphate

3 - 12 g. alkaline citrate .5 - 2 g. cupric sulphate 10 - 200 ml. silicone fluid 0 - 50 ml. silicone resin, and 37 - 62 ml. phenol.
By another aspect there is provided a process for preserving fresh, naturally coloured blooms comprising immersing said blooms in an essentially water-free composition consisting essentially of an effective amount of at least one dehydrating alcohol, a urea-containing compound, a carboxylic acid, and an alkaline citrate, and at least one of aluminum or magnesium sulphate, a transitional metal sulphate, and an alkaline formaldehyde sulfoxylate, and zero to an effective amount of at least one of a silicone fluid and a silicone resin,said composition also containing a sufficient quantity of at least one .~`~ I
'~ !

~05~

compound of the group consisting of an alkaline phosphate, and phenol so as to ensure said composition has a pH in the range 5 to 7.
By another preferred aspect of this invention there is provided a process for preserving naturally coloured plant tissues comprising immersing said tissues in a composition comprising 450-900 ml. of of at least one dehydrating alcohol 6-8 g. alkaline phosphate 2-3 g. alkali metal formaldehyde sulfoxylate 2~5-7.5 g. citric acid 10-20 g. thiourea 2.5-10 g. aluminum sulphate 3-12 g. alkali metal citrate .5-2 g. cupric sulphate 10-200 ml. silicone fluld 0-50 ~1. silicone resin, and 37-62 ml. phenol, removing said tissues from said composition and drying at substantially room temperature.
We have found that all blooms, substantially regardless of colour, can be successfully treated according to the invention by soaking, as described in more detail hereinafter, in a composition comprising (to make 1 litre):
175-575 ml. tertiary butyl alcohol 100-300 ml. l-propanol 200-400 ml. 2-propanol 6-8 g. sodium phosphate 2-3 g. sodium formaldehyde sulfoxylate 2.5-7.5 g. citric acid 10-20 g. thiorurea 2.5-10 g. aluminum sulphate 3-12 g. sodium citrate .5-2 g. cupric sulphate 10-200 ml. silicone fluid 0-50 ml. silicone resin, and ~r,l _ 3 _ g~

37 - 62 ml. phenol (88%) As used herein, the term "bloom" excludes the green parts thereof. Vari-ations of constituents within the above ranges are possible and even desirable for treatment of partlcularly coloured blooms as will be dis-cussed in more detail hereinafter. A "universal"composition, however, which has been found effective for virtually all colours and blooms and which is clearly advantageous as it simplifiesinventory and stock control and is particularly suitable for sale as a consumer-product, comprises (per litre):
375 ml. tertiary butyl alcohol 200 ml. l-propanol 300 ml. 2-propanol 12 g. sodium phosphate 2 g. sodium formaldehyde sulfoxylate 5 g. citric acid 10 g. thiourea S g. aluminum sulphate 6 g. sodium citrate 1 g. cupric sulphate 63 ml. silicone fluid 25 ml. silicone resin, and 37 ml. phenol (88%).
The invention will be described in more detail hereinafter with reference to the specific examples. It will be appreciated that there are three objectives of the treatment according to the present invention (a) dehydration of the blooms, (b) preservation of colour, and (c) protection of treated blooms.
It is known that in order to preserve a bloom all water must be eliminated from the bloom. It is also known that many monohydric alcohols, and in particular tertiary butyl alcohol, are extremely efficient dehydrating agents. Although any one or more such dehydrat-ing alcohols may be used we have found that a mixture of tertiary butyl alcohol, l-propyl alcohol and 2-propyl alcohol is particularly effective for the treatment of flowers. The tertiary butyl alcohol (all

- 4 -L9So ~ ol~ffo~7 proportions hereinaEter are per litre of treating~ n, unless ~~~ otherwise stated) can vary from 175 ml. to 575 ml. with a preferred concentration of about 375 ml. Generally, the more tertiary butyl alcohol relative to the other two alcohols, the shorter the period of time of immersion and vice versa. The dehydrating properties of terti-ary butyl alcohol are so considerable that the final product bloom tends to be brittle if not compensated by the inclusion of a silicone fluid, such as Microfil ~ MV-diluent, in the formulation. The upper limit of tertiary butyl alcohol, relative to the l-propanol and 2-propanol is controlled at least in part by the fact that tertiary butyl alcohol free~es at 24C.
The l-propanol and 2-propanol components are in themselves effective dehydrants and tend to modlfy the harsh effects of tertiary butyl alcohol used above, without interfering wlth its effectiveness.
The amount of these components i~ not critical to the formulation pro-vlded modifications to the other components are al~o made.
Sodium phosphate dibasic or other alkalina phosphate, such as potassium or ammonium phosphate is added to the formulation to control or buffer the pH. It has been found that pH control of the formulation i8 necessary for conslstent results and preferably the pH should be in the range 6.0-6.5. If no green i9 present in the bloom to be treated the pH may be as low as 5 and pH 7 is preferred for the treatment of green. It will, of course, be appreciated that most blooms to be treated will include a green stem and for this reason alone the preferred pH
will be in the range 6.0-6.5.
Sodium or other alkaline formaldehyde sulfo~ylate is optional-ly added to the formulation for its bridging properties and is particul-arly useful in the treatment of white blooms. It tends to speed up the setting of the colour and although omission thereof does not cause any essential change in results, the overall quality of the preserved blooms, especially white blooms is reduced.

A carboxylic acid is employed primarily as a colour preservative ~Q~Lg~
for red, pink, yellow and white. Suitable acids include tartarlc acid, butyric acid, salicylic and carbolic acid, and citric acid is preferred.
Although the amount can be varied widely between the limits descrLbed hereinabove, a carboxylic acid such as citric acid cannot be eliminated.
Too low a concentration causes the colours to appear faded, especially in red flowers. Too high a concentration can cause burning or coLour changes, particularly in the green portions of the flower.
A urea-containing compound is an essential COnStitUellt to prè-vent loss of pigments from the blooms and, when used together with citric acld a1,ld sodium citrate, it increases the efflclency of those chemicals o~Os~f~
and prolongs the active life of thei_~L.$i3R. Thiourea is a preferred urea-compound. Insufficient thiourea or other urea-containing compound causes the colours to appear dead and lacking in their original fresh beauty, and some colours may even change completely, as for instance a blue orchid ma~ turn a slckly red or pink. Exce~lve thiourea is not believed to have any deleterious effect except to increase the cost of the formulation.
Aluminum sulphate is an optional constituent in the formulation which appears to affect the overall quality of the colours of the blooms.
Too much aluminum sulphate (more than 100% excess) may cause spots resembl-ing burns on red and blue petals. Magnesium sulphate may also be employed but tends to be hygroscopic.
Sodlum or other alkaline cltrate i8 added as a colour preserva-tive for blue, purple and orange blooms and is used in conjunction with thiourea. Omission of sodium citrate causes the colours to appear faded.
Excess sodium citrate does not appear to affect blue, purple or orange - blooms but red and pink blooms are adversely affected.
Cupric or other transitional metal (Fe, Ni) sulphate is an optional constituent added not only to fix the colour of the blooms but also to draw away moisture which gathers at the bottom of the treatment tank through repeated treatment of the blooms, thereby extencling the life C~p~s~hon of the ~ ~P~e~. Excess of cupric sulphate tends to fall to the bottom ~l~9~1~51D

of the tank undissolved but there is some risk of burns to the blooms.
A silicone fluid, such as a silicone rubber injection com-pound sold under the trademark Microfil~ (MV-diluent~ by Canton Biomedical Products Inc. of Boulder, Colorado or dimethyl siloxane polymer sold under the trademark Dow Corning 200 by Dow Chemical Corp., is added to the formulation to fulfil the thlrd objective of the treatment, namely to protect the final product from humidity and temperature. The silicone fluid als~ has the effect of reducing the brittleness of the bloom caused by the use of the alcohol dehydrating agents. The silicone fluid impregnates the tlssue of the blooms as it is being preserved and also tends to strengthen the petal-torus ~unction. Reduction of the silicone fluid below about 30ml./1. results in visibly inferior products but an excess of the silicone fluid has no visible eEEect and merely increases the cost of the formulation.
In order to further protect the preserved bloom against humidity and improve the water repellancy thereof a silicone resin such as Microfil ~ MV~132 Clear which is a silicone polymer sold by Canton Biomedical Products Inc. or SYL-OF ~ Dow Corning Fluid 1107, may be incor-porated. It is stressed that neither the siliconefluid or polymer play any part in the colour preservation of the blooms but they do affect the physical properties involved in the resistance of the blooms to withstand mechanical and environmental stresses, essentially rough handling, humidity and temperature.
Phenol is preferably added to the formulation to enhance the efficiency of the other constituents. It appears to act as a pH
buffer, as a dehydrating agent and to aid in locking in the colours.
It is stressed that many of the solid compounds in the formulation are insoluble or only sparingly soluble in the organic liquids in the composition and tend to settle out. It is improper, therefore, to refer to a solutio~'which would imply complete dissolution. Although not wishing to be bound by this explanation it is believed that the solid components enter solution by way of the water extracted from the blooms as dehydration thereof proceeds, as explained in more detail hereinafter.

~1 - 7 -, ~
,i,,~

~o~

The process to treat the blooms according to the present invention is quite simple and straightforward. A fresh bloom is chosen and a floral wire is inserted into the stem or bloom and a weight is added to keep the bloom submerged in the composition. The composition, formulated as described hereinabove is contained in a suitable bath or container at a temperature in the range of about 45-70F. The bloom is left suspended in the composition for from 6 to 24 hours without any agitation, depending upon size and water content of the bloom and the freshness of the composition.
Upon immersion in the composition substantially all colour appears to disappear from the petals as dehydration occurs under the action of the dehydrating alcohols. The colour slowly returns to the normal pre-treatment level as the solid colour fixers and the like take up the extracted water and actively enter so}ution thus giv:Lng a useful indication oE the treatment time required. Large, fleshy blooms ~equire longer period of immersion and care must be taken to ensure thebloom is immersed sufficiently long to treat the relatively heavy and impervious torus. Following the immersion treatment thebloom is removed from the composition and air dried at room temperature and relatively low humidity for 8 to 10 hours. Blooms thus treated can generally be stored and displayed without further treatment for relatively long periods of time (of the order of ~-6 months at least) provided the temperature and humidity conditions are suitable (i.e. up to about 80F and 60-70% relative humidity). More stressful environmental conditions require that the blooms be stored in sealed glass domes, where they will likely last for years, or be further coated. It has been found that dipping or spraying with a conformal coating resin, such as Dow Cornin ~ R~3117 Silicone Resin alone or diluted with Dow Cornin ~
Fluid 200 (at 0.65 centistokes) or any other diluent, is satisfactory for this purpose. Preferably the coating is applied by dipping the bloom into the resin thinned with a diluent such as xylene at a temperature in the range 50-80F for a few minutes, The coated bloom is then dried at room temperature for several hours to cure the resin coating. The resin cures to a clear, transParent, shiny coating and leaves the bl~oom ,, relatively pliable. The shiny surface is often desirable but if a matte surface is desired this can be sprayed on with any one of a number of known finishes. The thickness of the coating has a bearing on the appearance of the bloom --thin coatings lend a natural and delicate appearance to the bloom9 while thick coatings make for sturdy blooms often of special beautyO After a coating treatment as described herein, roses and geraniums for example, have been exposed to light equal to several million foot-candle-hours, 95% humidity and temperatures up to 85F
with only slight colour fading. Under more norrnal conditions the colours remain unaltered.
Example 1 A series of preserving compositions ~ere prepared using mLxtures of tertiary butyl alcohol, l-propanol and 2-propanol to which the following components were added and at least partially dissolved, in sequence so as to maintain the pH of the composition throughout mixing in the range 6-6.5; dibasic sodium phosphate, sodium formaldehyde sulfoxylate, citric acid, thiourea, aluminum sulphate, sodium citrate, cupric sulphate, Microfi ~ MV-diluent, Microfil~ MV 132 Clear, and phenol, in amounts per litre as set forth in Table I:

T
o _ __ __ _ . __. _ ~, C ~ ~n ) I_ O~ ~n 1- ~n ~ ~_ O O ~
.._ __ _ ___ _ . _ __ . . _ Il ~ ~n ~ I_ ~ 0~ ~n ~..
o ~ ~ ~ o o ~ 3 . o~ o~ ~ ~ ~o o ~ ~3 _ _ __ _ ~ o o ~ =.~
I IH I 1 ~ 0~ 1-- ~¦ ~ ~ ~ ~ I O O ~1 O
I _ ~ ~n ~> I_ a~ o o ~n ~ I_ O O ~ O
__ _ ~ ~n ~ I_ o~ ~ O ~n ~ I_ O oo ~ O
_ _ __ ~ ~ ~ 1~ ~ ~1 ~1--I ~ 1~ O~ 0 ~n ~
1- ~ ~ ~ - ~ ~1 ~1 ~ ~ ~ o o~ ~n ~0 l ~ ~ ~ o ~ ~ o ~ ~ o o~ ~ ~3 1- ~ ~ ~ ~ ~1 ~ ~ ~ ~ ~ o ~ ~ ~o I I- ~n ~ _ ~n O ~n r~ ~- 0 O ~ ~ ~0 _ o~ _ a~ I_ ~ ~1 _ _ _ _ o -- h~

W ~ O ~ ~ ~n O ~n ~ ~_ O 0 ~ O
_ _ ._ _ _ _ .. _ _._ _ i _ ~ O ~ I_ ~ ~n I ~ ~ ~ ~_ ~ ~ ~ W,~~

5~

E~ample 2 Red roses, white and yellow chrysanthemums, blue and red fuchsia, yellow and pink hibiscus, red flowering maple, blue african violet and white and red geraniums were each preserved in each of compositions A-R as set forth in Table I hereinaboveO The stems of individual blooms were wired and the blooms suspended in the preserving compositions at room temperature (~5-70F) for periods ranging from

6-24 hours depending on the size and water content of the bloom and the freshness of the preserving solution. In some cases it was necessary to attach a weight to the wire to ensure total immersion of the bloom in the composltion. After the immersion treatment the blooms were removed from the solution and air dried at relatively low humidity (preferably less than 50~) for 8 to 10 hours. If higher humiditles are encountered it may be necessary to take speclal steps to avoid reabsorption of water, such as by immersion in a resin such as Dow Cornin ~ R~13117 with a solvent such as xylene. In some instances the dried blooms were subsequently coated with a coating or spray of a silicone resin at 50-80F. The results are set forth in Table II.

~ ~) L9S~

_ ---v _ _ _ _ _ _ _ _ _ ~ .o ~ ~ ~3: ~ 7~ ,, w c~ ~ ~ _ n w __ ~ q = _ = _ _ _ _ _ = = = -= _=-- _ O ~ O ~ ~ O O O O O O ~D O ~ O ~ P.
~3 n r~ s _ _ _ _ _ _ _ It o OoO ~ O Oo~ 04 O O ~Oq ~D~ 04 n ~ ~
. . _ _ _ _ ~ _ , , li _ O n ~ ~ 8 o o o ~o oO tDp~ ~ ~ ~ ~ n o~ ~ ~D

~s _ _ _ _ _ _ o~ ==~ c ~:

O O O O P~ P, rr O ID 1~ ~ P~ O O C C

O O .. _ O _ _ _ ~r _ . C- _ O C ~' ¦ ¦~ c c c ~ ~ n O O C O O O n O ~D O ~D C C C ~D

H tD ~ ._ _ M _ _ _ _ _ _ rr _ 1' O S rr O C ~ O O O O pr ,~ ~ r r ~D ~ C ~ ~D

rr rr ~:~' 1~ P CS
pO P~ n ~ ~) Oq ~ g O O O O P~ ~0 rn Pn~ n ~ C '=
rr r C _ CL 00 __ _ n _ _ _ = _ ~ C

C C Itl t P. O M O Pl O 1:~. n e ~ tt ~D C =' _ _ _ _ `~: _ _ ~t o~O~ oOq ~loq ~o ~ /J~o~ ~o tlo4 ~ C 1~} ~ ~oOq OC ~;e' ~ ~ C~ ~ tD ~ r D. ID `d ~ ID ~Ct ~ rr p _ _ _ _ _ _ _ _ . I
O O ooq O oo O O ooq P~ O O n U~ ~D
1:~. ~ ~ ~ ~ (D ~ ~ ~ ~ p rt - - - - - - - . - - -Olo~ Ooq ooq ooq O olo~ O o~o~ P~ Oq t n ~ o~
~ ~ ~ P. ~ ~ ~r ~~D C~ ~ ~t P

12 ~`

5~

From Table II it can be seen that composition A is a preferred solution for universal use. Modifications thereto can, of course, be made for treatment of specifically coloured blooms. Thus, elimination of sodium phosphate (composition B) results in relatively anemic flowers oE all colours, additional sodium formaldehyde sulphoxalate (composition C) is deleterious to yellow, red and blue flowers but appears beneficial to white flowers. Increasing citric acid (composition D) damages blue violets and fades yellows but enhances red flowers. Decreasing thiourea (composition E) fades all colours to some extent but in particular dark blue violets, while increasing thiourea (composition F) serves no useful purpose. Increasing aluminum sulphate (composition G) causes spotty red and blue flowers as it appears to cause a burning Ln the cellular structure of the petals, reductlon of aluminum sulphate (composition 1l) has little noticeable effect. Reduction of sodium citrate (compositLon J) causes fading of the blues and increasing sodium citrate (composition K) has no noticeable effect as most of the increase appears not to dissolve.
Reduction of cupric sulphate (composition L) had little effect on the blooms but turned the stems light in colour, while increasing cupric sulphate (composition M) merely resulted in undissolved chemical without effect on the blooms. It is believed however that excess cupric sulphate improves the aging properties of the composition as it appears to draw water from the alcohols. Reducing phenol (composition N) faded both red and yellow flowers and excess phenol (composition P) enhanced all blooms, especially red up to about 62 ml./l. but amounts in excess of this caused darkening indicating a burning effect. Additional silicone oil or resin (compositions Q and R) had little effect on the colour or texture of any of the blooms but lengthened the dehydrating times, due, it is believed, to the isolating properties of these compounds.
It will be appreciated that many modifications to composition and process of the present invention may be effected by those skilled in the art without departing from the scope and ambit thereof. For example, it has been found possible to add the dehydrating alcohol or ~c~9~gs~
alcohols to a mixture of the other components of the composition, with excellent results. This is advantageous from the point of view of market-ing and transportation as the bulk of the composition comprises the alcohol component and it may be preferable to obtain a suitable alcohol locally and mix it with a suitably packaged mixlture of the remaining constituents.

- ]~4 -

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An essentially water-free composition, for the single step preser-vation of fresh, naturally coloured blooms comprising in combination an effective amount of at least one dehydrating alcohol, a urea-containing compound, a carboxylic acid, and an alkaline citrate, and at least one of:
aluminum or magnesium sulphate, a transitional metal sulphate, and an alka-line formaldehyde sulfoxylate, and zero to an effective amount of at least one of a silicone fluid and a silicone resin and which composition also contains a sufficient quantity of at least one compound of the group consist-ing of an alkaline phosphate and phenol so as to ensure said composition has a pH in the range 5 to 7.

2. A water-free composition, for the preservation of fresh, naturally coloured blooms, as claimed in claim 1 wherein said urea-containing compound is thiourea; said carboxylic acid is citric acid, and said transitional metal sulphate is cupric sulphate.

3. A composition as claimed in claim 2 comprising, in amounts per litre:
700 - 900 ml. of at least one dehydrating alcohol 6 - 8 g. alkali phosphate 2 - 3 g. alkali formaldehyde sulfoxylate 2.5 - 7.5 g. citric acid 10 - 20 g. thiourea 2.5 - 10 g. aluminum sulphate 3 - 12 g. alkali citrate 0.5 - 2 g. cupric sulphate 10 - 200 ml. silicone fluid 0 - 50 ml. silicone resin 37 - 62 ml. phenol.

4. A composition as claimed in claim 3, comprising:
175 - 575 ml. tertiary butyl alcohol 100 - 300 ml. 1-propanol 200 - 400 ml. 2-propanol 6 - 8 g. sodium phosphate 2 - 3 g. sodium formaldehyde sulfoxylate 2.5 - 7.5 g. citric acid 10 - 20 g. thiourea 2.5 - 10 g. aluminum sulphate 3 - 12 g. sodium citrate 0.5 - 2 g. cupric sulphate 10 - 200 ml. silicone fluid 0 - 50 ml. silicone resin 37 - 62 ml. phenol.

5. A composition as claimed in claim 1 wherein said silicone fluid is present in an amount of at least 30 ml./1.

6. A composition as claimed in claim 1, comprising:
375 ml. tertiary butyl alcohol 200 ml. 1-propanol 300 ml. 2-propanol 12 g. sodium phosphate 2 g. sodium formaldehyde sulfoxylate g. citric acid g. thiourea g. aluminum sulphate 6 g. sodium citrate 1 g. cupric sulphate 63 ml. silicone fluid ml. silicone resin 37 ml. phenol.

7. A single step process for preserving fresh, naturally coloured blooms comprising immersing untreated said fresh blooms in an essentially water-free composition consisting essentially of an effective amount of at least one dehydrating alcohol, a urea-containing compound, a carboxylic acid, and an alkaline citrate, and at least one of aluminum or magnesium sulphate, a transitional metal sulphate, and an alkaline formaldehyde sulfoxylate and zero to an effective amount of at least one of a silicone fluid and a silicone resin, said composition also containing a sufficient quantity of at least one compound of the group consisting of an alkaline phosphate, and phenol so as to ensure said composition has a pH in the range 5 to 7, for a period of time sufficient to effect complete dehydra-tion.

8. A process for preserving fresh, naturally coloured blooms as claimed in claim 7, wherein said composition consists essentially of at least one dehydrating alcohol, thiourea, an alkaline phosphate, citric acid, an alkaline citrate, a silicone fluid, and zero to an effective amount of at least one of: aluminum sulphate, a silicone resin, cupric sulphate, an alkaline formaldehyde sulphoxalate and phenol, and including immersion for a period of time sufficient to effect substantially complete dehydration, and subsequent drying at substantially room temperature.

9. A process for preserving fresh, naturally coloured blooms as claimed in claim 8 wherein said blooms are immersed in a composition of:
175 - 575 ml. tertiary butyl alcohol 100 - 300 ml. 1-propanol 200 - 400 ml. 2-propanol 6 - 8 g. sodium phosphate 2 - 3 g. sodium formaldehyde sulphoxalate 2.5 - 7.5 g. citric acid 10 - 20 g. thiourea 2.5 - 10 g. aluminum sulphate 3 - 12 g. sodium citrate 0.5 - 2 g. cupric sulphate 10 - 200 ml. silicone fluid 0 - 50 ml. silicone resin, and 37 - 62 ml. phenol.

10. A process as claimed in claim 9 wherein a substantially transparent moisture resistant resinous coating is applied to said blooms after drying.

11. A process as claimed in claim 8 wherein said composition has a pH in the range 6.0 - 6.5.

12. A process as claimed in claim 8 wherein said composition contains:
375 ml. tertiary butyl alcohol 200 ml. 1-propanol 300 ml. 2-propanol 12 g. sodium phosphate 2 g. sodium formaldehyde sulphoxalate g. citric acid g. thiourea g. aluminum sulphate 6 g. sodium citrate 1 g. cupric sulphate 63 ml. silicone fluid 25 ml. silicone resin, and 37 ml. phenol.

13. A composition as claimed in claim 1 wherein said silicone fluid is selected from Microfil? MV-diluent and dimethyl siloxane.

14. A flower treated with a composition as claimed in claim 1.

15. An essentially water-free composition of matter, for admixture with a dehydrating alcohol for the preservation of fresh, naturally coloured blooms, consisting essentially of an effective amount of a urea-containing compound, a carboxylic acid, an alkaline citrate, and at least one of aluminum and magnesium sulphate, a transitional metal sulphate, an alkaline formaldehyde sulfoxylate and from zero to an effective amount of a silicone fluid and a silicone resin and a sufficient quantity of at least one compound selected from the group consisting of an alkaline phosphate, and phenol to ensure a pH of 5 to 7.