BULLETIN

OF THB

American Iris Society

NOVEMBER, 1945 No. 99

CONTENTS

Editor’s Bulletin Board _ 1

After Three Years, Dr. Franklin Cook _ 3

Officers Re-elected _ 9

Mystery of Soft Rot, Jesse E. Wills. _ _ _ 10

Propagation of Louisiana Iris, Ira S. Nelson _ 14

Iris in Weather Gone Awry, Ralph M. Schroeder _ 21

Presby Memorial Garden, C. H. Caldwell _ 25

Review of the Season, Mrs. Ralph E. Ricker _ 28

Lesser Known Iris, Dr. George M. Reed _ _ 37

Iris Through the War in Italy, Countess Senni _ 48

Iris Genetics, A. H. Sturt evant and L. F. Randolph _ 52

Iris Ratings, 1945 _ 66

Comments on Varieties _ 70

Our Members Write :

Favors Test Gardens, Dr. Lewis Clevenger. _ 92

Published Quarterly by

THB AMERICAN IRIS SOCIETY, 32nd ST. AND ELM AVENUE, BALTIMORE, MD. Entered as second-claBS matter January, 1934, at the Post Office at Baltimore, Md., under the Act of March 3, 1879.

$3.00 the Year Additional copies 50 cents each for Members

THE AMERICAN IRIS SOCIETY

OFFICERS 1945

Directors :

Terms expiring 1945: F. W. Cassebeer Geddes Douglas

Terms expiring 1946: J. P. Fishburn David F. Hall

Dr. H. H. Everett Dr. R. J. Graves

E. G. Lapha^a W. J. McKee

Terms expiring 1947 : Dr. Franklin Cook Carl S. Milliken

Howard R. Watkins Jesse E. Wills

President Mr. Jesse E. Wills, Belle Meade Blvd., Nashville, Tenn. Vice-President Mr. Junius P. Fishburn, Box 2531, Roanoke, Va.

Secretary Mr. Howard R. Watkins, 821 Washington Loan and Trust Bldg., Washington, D. C.

Treasurer Mr. E. G. Lapham, 1003 Strong Ave., Elkhart, Ind.

Editor F. W. Cassebeer, 953 Madison Avenue, New York 21, N. Y.

Assistant Editor Miss Marcia Cowan,

Regional Vice-Presidents

1. W. J. McKee, 45 Kenwood Ave., Worcester, Mass.

P. Kenneth D. Smith, Benedict Road, Dongan Hills, Staten Island, N. Y.

3. John Dolman, Jr., 204 Vassar Ave., Swarthmo~e, Pa.

4. J. Marian Shull, 207 Raymond St., Chevy Chase, Md.

5. T. N. Webb, Durham, N. C.

6. Mrs. Silas B. Waters, 2005 Edgecliff Point, Cincinnati, Ohio.

7. W. F. Cahoon, R 4, Cahaba Road, Birmingham 9, Ala.

8. Mrs. W. F. Roecker, 3319 North 14th St., Milwaukee, Wis.

9. O. W. Fay, 1522 Isabella St., Wilmette, Ill.

10. Frank E. Chowning, 2110 Country Club Lane, Little Rock, Ark.

11. Mrs. Mary F. Tharp, Payette, Idaho.

12. Merritt H. Perkins, 2235 Fairfax St., Denver, Col.

13. Dr. R. E. Kleinsorge, Silverton, Ore.

14. Mrs. G. G. Pollock, 1341 45th St., Sacramento, Calif.

15. E. E. Nies, 1423 North Kingsley Dr., Hollywood 27, Calif.

16. W. J. Moffatt, 170 Delaware Avenue, Hamilton, Ont., Can.

Chairmen of Committees:

Scientific Dr. L. F. Randolph, Ithaca, N. Y.

Election Dr. George M. Reed, Brooklyn Botanic Garden, Brooklyn, N. Y. Membership and Publicity W. J. McKee, 45 Kenwood Avenue, Worcester,

Registration— C. E. F. Gersdorff, 1825 No. Capitol St., Washington 2,D. C. Ass’t. to Registrar— Mrs. Walter Colquitt, 487 Albany, Shreveport, La. Exhibition Mrs. Ralph E. Ricker, 1516 Ross St., Sioux City, Iowa. Recorder of Introductions and Bibliography Mrs. W. H. Peckham,

The Lodge, Skylands Farm, Sloatsburg, N. Y.

Awards Junius P. Fishburn, Roanoke, Va.

Japanese Iris— Dr. George M. Reed, Brooklyn Botanic Garden, Brooklyn, N. Y.

IRIS CHECK LIST, 1939 Lists 19,000 names of iris and parentages; over 500 pages. Price 0.00 to members; $4.00 to non-members.

LANTERN SLIDES Rental Fee (to members) $5.00. Apply to Mrs. P. E. Corey, 707 Pearl St., Reading, Mass.

THE EDITOR’S BULLETIN BOARD

This number of the Bulletin is in the nature of a swan song* for it will terminate the work of the present editor. Since assum¬ ing the A.I.S. editorship in the spring of 1940, we have completed 23 issues and now feel that it is time to relinquish our post. We asked the Directors to be relieved of our duties because it became increasingly evident that we could not fulfill our growing business obligations and still have enough time at our disposal to do an effi¬ cient job of editing.

We are grateful for the many articles that were so generously contributed by members of the Society during our six years of editorship, and we appreciate the infinite patience of the readers who so graciously tolerated the many delays in the publishing of the Bulletin, especially during the war period.

Beginning with Bulletin No. 100, the reins of editorship will again be in the capable hands of Mr. Robert S. Sturtevant, who was responsible for the many excellent issues in the early days of the Society. He will be ably assisted by Mr. Geddes Douglas and since both live in Nashville, they will be able to cooperate closely with our president, Mr. Jesse E. Wills. We feel sure that they will be accorded the same support from the readers that we have always enjoyed.

F. W. Cassebeer, Retiring Editor.

[1]

F. W. Cassebeer

Chamois , a recent introduction of Dr. R. E. Kleinsorge, has attracted wide attention.

[2]

AFTER THREE YEARS

Dr. Franklin Cook

The 1945 iris season was the most exciting one I can remember for a long time. There are no iris on Saipan, nor in the Marshalls, and except for brief glimpses at Mr. White’s out-of-this- world oncobreds at Redlands, and Prof. Mitchell’s earliest out-of-season tall beardeds in April 1944, I had completely missed the iris parade for two seasons. Imagine my delight, then, at returning to see some of the newer iris in colors heretofore unknown to me.

Perhaps distance lends a new perspective, or again it may have been that I had become familiar for the first time in my life with real tropical colors brilliance unmatched in the North. However that may be, I was glad to find that many hybridizers were hard at work producing new clear colors in flowers of considerable sub¬ stance, excellent form and good branching, instead of bringing out the usual hundreds of mediocre “improvements” over existing varieties that have characterized American introductions for longer than I like to remember.

These notes are being written after visiting, this June, about a dozen large Northern iris gardens, mostly in Regions 6 and 9. I am sure I have missed many noteworthy Eastern and Western novel¬ ties which may not yet have become widely distributed. Even so, I feel that I have seen a great many new and outstanding iris which were not generally well known three years ago. After the 1942 season, I collected my notes and wrote in Bulletin No. 87 a short article on what I considered “My Perfect Iris.” What new vari¬ eties shall I now add to that select group? Again I shall group them by color.

W hites

White iris, in their purity of color, have always held a strong fascination for me they may be at once so alike and yet so differ¬ ent. For a low-growing mass of pure alabaster, I have seen nothing to equal Priscilla, the whitest of the white iris. Patricia and Birchbark make splendid clumps of medium-sized flowers in pro¬ fuse and well mannered habit, neither sprawling all over the place

[3]

nor untidy. Sierra Snow, also a very pure wliite, delightfully ruf¬ fled and of medium size, but taller than any of the foregoing, is a bit temperamental, as perhaps becomes a diva, but at her best is still tops in her class. Larger than any of these are three fine flowers that have stood the test of time and have proved themselves super iris Matterhorn, White Goddess and White Valor, the last quite late. Large clumps of these fine “standard” whites compare well with any novelty in the garden, and I would propose that no new whites be introduced in the future unless they are noticeably superior to these three.

I know of one new white that meets this test Orville Pay’s New" Snow. Huge, full-bodied, stiff and beautifully ruffled, this white bids fair to outdo all others in this class. Alba Superba, when vTell grown, might be a keen competitor. Snow Carnival, Cotillion and Franconia I ’ve not seen nor Lady Boscawten.

The blue-white class of iris is just no'w emerging into full stature. Snow Flurry, although somewhat tender here, is definitely distinct, even if it is top-branched. White City (Dykes Medalist 1939) is quite different in form and both larger and better branched. And Thou has still more blue in beard and style arms. White Wedge- wood was one of the most thrilling novelties to greet me when I re¬ turned.

I had a dozen blue-bearded whites in my seedling bed this year, but none quite so lovely as White Wedgewood. The contrast of its deep blue beard to ice-white petals is perfectly stunning. The flower is heavy substanced and ripples and ruffles in a delightful manner. The stalk is slender but adequate, and vrho wants a tree- trunk anyway?

In the creamy wdiites or yellowy-throated whites, I have seen noth¬ ing to beat Mary E. Nicholls. Snow Velvet is somewhat larger and a wonderful doer, just as leathery-substanced and taller, but the two can hardly be compared. “Mary” has more gold laid on more smoothly than any other flower in irisdom. Arctic is some¬ what tender here and I have had to discard it wdth regret. Caro¬ line Burr is fine every other year or so ; wdien she ’s good, she ’s very, very good, but wdien she’s bad, she’s an untidy vdtch. Grant’s Frank Drake is reported a splendid new cream, and Douglas’ Amandine, a grand off-white. Vision Fugitive is still fugitive from me. I can’t find it anyvdiere.

[4]

Blues

New blues by the dozens are arriving on the scene, and welcome they are mostly the progeny of Great Lakes. Are they bluer than their parent? Well, Jesse Wills’ Chivalry is by a great deal! When I first saw, it I could hardly believe my eyes a fine deep to medium blue, remarkably clear, heavy substanced, ruffled and flar¬ ing. What a break ! From all reports it is one of the most sought- after iris in the country today, and I would rate it as the most de¬ cided advance in clear color I have ever seen. I have not made the acquaintance of Lake George, Gallantry, Saint Regis, Blue Rhythm, Blue Valley or Helen McGregor all reported to be exceptional^ good blues of various depth of hue. Mr. Hall’s most knock-out iris of 1945, in my opinion, was a frosty light blue of huge size and classic form : Silvertone. Paul Cook had a fine seedling of slightly more silvery tone, and Mrs. Whiting still an¬ other. The “true blues” are at last arriving after decades of effort to remove that purplish tinge all our former 1 1 blue iris pos¬ sessed. Can this pigment be still further purified by selection and reselection? The last two years have shown more improvement in this respect than the previous twenty !

Yellows

Yellows are “clearing” too. Berkeley Gold was one of the most striking iris I saAV this year. It seems the fanciers almost passed it by because of its modest introductory price. Grown near such fine yellows as Spun Gold and Golden Majesty, Berkeley Gold made them seem dull, drab and muddy by comparison ! With good growth habits, fine branching and vigor, it is by all odds the finest golden yellow self I’ve seen.

Ola Kala, in a somewhat orange tone, presages an entirely new color for our favorite flower. Till now, our approach to orange has been made from the brown direction, as in Naranja. Ola Kala is orange-tinted without a trace of brown, and although its plant habits are not of the best, its color is novel and strikingly clear.

In the lemon-toned light yellows, which, by the way, have long outgrown the title of “the Elsa Sass class,” Moonlight Madonna has proved especially fine and is one of my favorite iris. Immacu¬ late is the name for her, and she has none of the faults of “Elsa.” Full-bodied, wide-hafted, pure-colored, heavy-substanced, well branched, she embodies all those important qualifications of a good

[5]

iris besides the virtue of her frosty lemon coloring. As a foil for orchid and mauve colored iris Moonlight Madonna is superb. Schreiner's Misty Gold, full petaled and ruffled, with gold braid¬ ing all along the margins, promises to take a leading place in this important color class. Essig’s Soxtsun has been highly praised by those who know quality, and we will watch this iris' performance with interest. I have it planted with Dreamcastle and Harriet Thoreau.

Of the whites, blues and yellows all showing remarkable ad¬ vances top honors (among those I've seen) go to White Wedge- wood, Chivalry and Berkeley Gold.

Pinks

When we come to pink, let me say that I have found that 4 pink ' ' means a different hue to a rosarian, a peony fancier and an iris breeder. It means a different hue to a doctor, a candy manufac¬ turer, an attorney and an eight-year-old child. Be that as it may, I want to differentiate mainly between pink seifs of whatever shade of pink, and pink Mends like Daybreak, in which the pink and yel¬ low are discernible as separate colors no matter how much over¬ lapping there is.

In the class of so-called “seashell pinks" heralded by Loomis' Spindrift and No. V-20, Mr. Hall has by combining several pink strains produced a few seedlings that are quite definitely pinker than anything I had seen in 1942. Cherie and Hit Parade are two of the newest. Many seifs shading towards salmon-pink and on the order of Remembrance also are showing up along with quite a few that can best be described as “peach" pink. One of the most lus¬ cious of these is Pay's No. 44-36 which I expect must be introduced soon, for to see it is to want it badly! A medium-sized flower of exceptional substance and weather resistance, it is a true self of un¬ marred clarity, both brilliant and refined, a brand new color in iris, and one of the most lovely shades imaginable. Add to this, good branching and height, sturdy growing habits, attractive foliage and a capacity to stand hot sun without fading and we have a new star in the iris world. Planted with the frosty light blues, it will be gorgeous.

Toward the orchid side of pink, Paul Cook has quite suddenly brought this color out of the small-flowered Pink Satin and Im¬ perial Blush class into full-bodied, large flowers of heavy sub-

16]

stance, all in one jump. Harriet Thoreau and Dreamcastle are very, very fine. I prefer Harriet Thoreau. Orchid pinks have wonderful garden value, and in association with creams and “lem¬ on-ice yellows” make a stunning picture. Heretofore we have had only the old-time 24- and 36-chromosome pallida- strain orchid pinks. With these two new ones the orchid coloring is now represented in two fine flowers of large size and good all-around quality.

Passing to the pink blends, .Mrs. Whiting^ Tea Rose, Grant ’s Coral Mist, Nelson’s Show Girl and Hall’$ Chantilly are all sur¬ passingly good. In Chantilly, Mr; Hall has unearthed a unique recessive /factor that of extra-heavy crimped petal edges. The bud tips are triple-horned instead of single-pointed and the fully opened flowers are lacy-edged all around and three times as thick as an ordinary iris petal. This factor is a distinct novelty, and a valuable one.

Coppers, Tans, Browns

I have always dreamed that someday there would be an iris of rich gleaming copper almost a burnt orange. Many blends have approached it from quite a distance, but when I found Bryce Can¬ yon this year I realized that here was the closest approach yet, in a perfectly stunning flower. Bryce Canyon was the one iris I had to have this year, and I had my check returned b}^ three dealers before I finally induced someone to sell me one. The color is de¬ scribed as henna-copper, but this description gives no impression of the depth of lustre and the glowing undertones in the flower. Its pace-setting record in the H.M. balloting this year means that a lot of other judges feel the same way about it as I do. It is simply gorgeous and I can hardly wait for my single plant to become a clump with creams and medium blues nearby. In somewhat more subdued tones of brown Tobacco Road and Casa Morena took my fancy. In still different shades Russet Wings and Jasper Agate were excellent. Copper River is held by some to be excellent, while good reports on Douglas’ Copper Glow continue to come in. Hall’s Golden Russet is, I think, the most tremendous iris extant, but is neither golden nor russet, nor hardly even an iris, it is so huge !

Lavenders

Another color that has just “come of age” is true lavender. We now have in Mr. Hall’s Lynn Langford and Lavender Mist two perfectly beautiful new pure silvery lavender flowers of all good

[7]

habits. Carpenter’s Silver Lustre is reported to be another. These are not blends and are so utterly distinct from anything that has gone before that they belong in an entirely new color class a grand addition to the iris rainbow !

Reds

Darker and much redder than these three and a magnificent brand new color was Mulberry Rose. One sees it a block away and it is one of the most delectable colors I have ever seen in any iris. Close inspection reveals no faults, although I would like to see someone put ruffles on it. This one I must have. In the same color range but more bronze and rosy was Red Amber, a smooth flower if I ever saw one.

Red has never been a favorite color of mine, largely because it combines so poorly with other colors, and on my return I found nothing in this class that I would prefer to Mrs. Whiting’s Garden Glory, which I still maintain is the smoothest deep red-toned iris yet produced. Many were larger, a few were redder Lights On, Flamely and many unintroduced seedlings. But I’ll take Garden Glory. Solid Mahogany I’ve not seen.

Dark Purples , Maroons

Among the darkest purples and maroons, I found little improve¬ ment over the finest of two years ago. No iris in my garden were more exclaimed over than Captain Wells, Sable, Deep Velvet and Indiana Night. Kenneth Smith’s Lord Dongan, planted with deep yellows, was very striking and fine. I think this entirely dis¬ tinct and lovely iris deserves much more praise than it has received. Mary Williamson’s mulberry toned Master Charles was the only really new one in this color class that stood out as a decided ad¬ vance in this populous group. Master Charles eludes description as to why it is so good. Perhaps it is the unusually fine flaring form, or the rich glowing sheen on the pure purple petals when the sun strikes them. But it’s very fine.

Trends in Breeding

After three years’ absence from the iris scene, I notice these healthy tendencies in American iris breeding :

(1) A new emphasis on CLEAR COLOR, and an almost entire absence of introductions of muddy blends disguised as “art shades.”

(2) The production of iris of entirely new colors and combinations of

[8]

colors, as the new buff-pinks, true lavenders, bluer blues, clearer golden yellows and orange-coppers.

(3) A growing unwillingness of breeders to introduce new varieties until they have been tested for hardiness for a number of years , often in differ¬ ent sections of the country, and until sufficient stock has been accumulated to permit introduction at a reasonable price.

(4) Education of the iris buyer through experience that he need not pay ridiculous prices for highest quality novelties. Examples : Chivalry ($15), Bryce Canyon ($10), Berkeley Gold ($5). Who can name bet¬ ter iris in these colors at any price?

(5) A welcome insistence on the part of the public on plants of good vegetative characteristics, apart from color novelty, and a greater appre¬ ciation of what constitutes a “good iris.”

And still, these tendencies are only straws in the wind. There are too many introductions of mediocre plants, too many breeders who never get the word,” or are too eager to father a novelty before it proves itself. The result of such promiscuous fatherhood is quite obvious from the most cursory glance at any of our iris catalogs. Perhaps now that the travel situation has eased up a bit and breeders can compare their novelties more easily, we will get a little more selective all around, with decided advantages accruing to the iris-buying public.

OFFICERS RE-ELECTED

The election of officers of the Society was held by mail this year because the annual December meeting of the board of directors of the Society was cancelled due to transportation difficulties.

As a result of the poll of the directors, all officers were re-elected. They are: J. E. Wills, president; J. P. Fishburn, vice-president; H. R. Watkins, secretary, and E. G. Lapham, treasurer.

To succeed F. W. Cassebeer, retiring editor, the directors subse- quently appointed Robert S. Sturtevant as editor and Geddes Douglas, assistant editor.

Previously, all directors whose terms expired in 1945 had sig¬ nified their willingness to serve another term. As no further nomi¬ nations of directors were submitted by the membership, they were declared re-elected. They are: F. AY. Cassebeer, Geddes Douglas, Dr. H. H. Everett, and Dr. R. J. Graves.

[9]

THE MYSTERY OF SOFT ROT Jesse E. Wills

This past summer I had a peculiar and unwelcome visitation from bacterial soft rot which reminded me somewhat of the experi¬ ence of M. E. Douglas, decribed in Bulletin No. 76 (January, 1940), and also that of the Duke Memorial Garden described by John Wister in the same issue. The damage in my garden, although considerable, was not so severe as in either of these cases. It resem¬ bled them, however, in that it was hard to find any satisfactory ex¬ planation for it and in that the iris attacked were ones that would seem most likely to escape, while iris planted under less favorable conditions were immune.

I have been growing iris to some extent since 1933, and on a large scale since 1938. For years I had practically no rot and rarely saw a true case of it. My main troubles from disease were mustard seed fungus and leaf spot. I did have a good deal of true rot during the blooming season of 1943, as did the other Nashville growers. It often started up in the foliage or on the stalk and in some cases caused buds to rot away. Since then I have had some trouble from time to time in one bed of named varieties, which is too close to the drain¬ age from the septic tank, and which needs raising.

The worst experience I have had, however, was this summer when rot was 'almost totally confined to certain areas devoted to seedlings. My seedlings are grown in an open field where there is no shade except toward the edges. The earth looks good when it is plowed but is not so good as it looks. The soil is stiff and heavy and packs hard in the summer and is cold in the spring. It is a little on the acid side and lacks potash and humus. The field has a northern exposure and seems to be in a frost or cold pocket. Freezes and late frosts do more or less damage among the seedlings almost every year. This year the damage was very extensive when a very warm March was followed bv an early April freeze.

My seedlings are usually grown in rows in beds about 25 feet long and four feet wide, with narrow grass paths between7 the rows of beds. The section where the rot damage occurred had grown iris for a number of years, so after the blooming season of 1943 I cleaned

it out entirely to let it rest for a year. That fall I planted these empty beds in crimson clover, meaning to spade it under in the early spring when the beds were remade. However, the clover, mixed with some rye, grew taller than I had intended it to and labor was not available to spade it under. I therefore had the whole area plowed up, beds, paths and all. After the first plowing the area was limed and later treated with an 0-14-7 fertilizer mixture. Still later it was plowed again, cleaned up and leveled. I marked off rows across it three and one-half feet apart and had a little sheep manure sprin¬ kled along these lines and the soil pulled up over this along the row. My intention was to guard against any settling that might occur so that after the seedlings were planted they would be only a little above ground level. The man in charge of this job did not entirely understand my instructions, however, and he produced an effect that looked like a washboard with long mounds or ridges eight inches or so above the valleys. I had to plant my seedlings along the crests of these ridges. Because I was late in transplanting them, they did not grow much during the dry summer. This past spring they started to grow vigorously but only the first third that were transplanted, and about 20% of the remainder, would have produced much bloom even if we had escaped the freeze. As it was, most of the plants that tried to bloom were frozen so badly that the buds did not open at all or the flowers were so distorted that it was impossible to tell much about them.

I was very much afraid that rot would follow this freeze as there were many frozen buds down in the fans, but it did not and the seedlings continued to grow rather vigorously. The weather was rainy and cool until early in June when a dry spell followed for about a month, during which I watered the iris once or twice. In July there were some good summer rains, which caused the weeds to grow vigorously also and in cleaning out the rows I discovered soft rot all through the ridge plantings. Although I checked it to some extent, it continued to appear until cool weather and I still found occasional instances of it as late as the middle of October. I did not make an accurate count but estimate that 150 to 200 seedlings were lost and a good many others were damaged.

The rot did not start in the rhizome but began with the side leaves a few inches above the root and then spread downward into the rhizome. There was no rot among the named varieties in beds or in plantings against the shrubbery, or among the remaining 1944 seed-

[11]

lings which were planted rather close together in beds, or among a large number of 1943 seedlings which I had never cleaned out and which were choked with weeds. There was a little rot among the newly transplanted seedlings of the current year, which were also planted in beds spaced five or six inches in a row and with eight inches between rows, but there was not enough of this to be serious. The seedlings which had the rot were less crowded and had the best drainage of any iris in my garden. Why they had it, 1 don’t know, and no one has suggested a satisfactory answer. I considered all of these possible causes :

1. The weather. While we had good rains in July and it was a wetter summer than the previous one had been, it was not excep¬ tionally so. The garden had gone through midsummer periods much wetter and hotter without suffering any rot.

2. Lack of drainage and too much crowding. The affected iris had the best drainage and the least crowding of any in the garden. It is true that at the time I first discovered the rot, the iris were buried to some extent in weeds but this condition had not existed very long .and after a thorough clean-up the rot continued to appear and did not reach its peak until several weeks later. The seedlings carried over from the previous year were not cleared of weeds until late in the summer but they had no rot. Furthermore, several beds of 1943 seedlings were hidden by weeds and high grass but had no rot even though they were more crowded and had less drainage than the others.

3. An inherited tendency to rot. I do not think inheritance had anything to do with the condition nor do I think that it came from Totty strains of iris, as Mr. Douglas suspected in the case of his iris. The worst rot was among crosses of reds, pinks, and blends of paren¬ tages presumably hardy. The comparatively few white or blue crosses among the seedlings were largely free of rot.

4. Too much lime. The application of lime had not been heavy .and it had been used in other places where there was no rot. In fact, the old 1943 seedling beds had been limed much too heavily the previous fall but there was no rot among them.

5. The sheep manure. This was a common factor present with all iris that had rot as it had been used also in preparing the beds con¬ taining the newly transplanted seedling. It had been used also in a •great many other beds and plantings that had no rot. I have seen It and other manures used much more heavily by other growers

[12]

without causing any trouble. Also, it had been under these ridges for more than a year before any rot appeared. (I don’t particularly like sheep manure but it was all I could get at the time. Previously, in preparing beds I had used dried cow manure along with peat moss and humus from a compost pit made from dead leaves and grass clippings.)

6. Too luxuriant and soft growth. The growth in my back lot, while good, was not exceptional or any better than that of Geddes Douglas’ and Wentworth Caldwell’s iris. Some seedlings, as is always the case, were growing better than others but I noticed that the rot did not concentrate on the well grown ones. Some good-sized clumps were attacked but just as many small, weak-p^lantsy-whieh looked as though they had just been transplanted this year, were destroyed. It is true that the foliage growth on these seedlings was on the average somewhat better than it was among the named varieties and on the old seedlings in beds in other areas. In Nash¬ ville the foliage in a fan often tends to thin down to a few straggly leaves during the dry part of summer and these seedlings had better fans than the average of my garden but I still could not consider their growth exceptional.

7. A lack of balance in plant food. It occurred to me that there might have been too much nitrogen in proportion to the available phosphorus and potash and that the growth therefore was soft and lacked disease-resistance. This was merely a guess, however, and I had no proof of it.

There was not a great deal I could do about the rot. It was im¬ possible to dig the iris, clean them off, dry them out and replant them as I had no space for replanting. Also, in most instances there was nothing much left to save except a few tiny side-shoots. I did dust every plant in the rows affected with Cupro-jabonite some of the rows more than once— and I tried to scrape out the rot. I also gave special treatment to the plants most affected when there was anything left to save and dug out the plant and discarded the plant when there was nothing much left. In the case of one or two crosses in which I was particiularly interested, I also soaked the plants with Semesen solution and used the copper carbonate. Later on in the summer, acting on the wild guess that there was not enough phos¬ phorous and potash in proportion to the nitrogen available, I sprin¬ kled more of the 0-14-7 fertilizer along the rows.

Soft rot is still a mystery. The latest articles in the Bulletins on

[13]

the cause and treatment of rot repeat more or less the same things that can be found in Bulletins printed in the early.. ,1920 ’s. The usual treatments prescribed are fairly , satisfactory, if one has only a small planting with which to deal. They are impractical in the case of a large planting of thousands of seedlings unless one has more labor and more room than were available to me this past sum¬ mer.

I am inclined to think that susceptibility to rot varies from time to time. Whether this is due to changes in the virulence of the or¬ ganisms causing it, or whether it is because of some complexity of plant nutrition too much, or too little of some plant food including the “trace elements or some lack of balance between them I do not know.

PROPAGATION OF LOUISIANA IRIS Ira S, Nelson

Southwestern Louisiana Institute , Lafayette , La .

To propagate is to perpetuate or to increase. Any of the meth¬ ods used in the propogation of Louisiana iris may perpetuate or increase their population, but certain methods are distinctly superior to others in particular circumstances. It is proposed to review here already known methods as well as to report on a new method not yet mentioned in the literature. The relative merits and limitations of the various propagation procedures should be carefully studied before they are tried, if one expects to reap the full harvest of his labors.

Propagation by Seed

Seed are borne in profusion by Louisiana iris. Each bloom may produce a pod containing from five to 50 seed. Propagation by seed offers a means of getting large quantities of plants at low cost.

Propagation by seed is desirable if trueness to variety and time are not important factors. Species may be propagated to type by seed but this is seldom possible with horticultural varieties. Seed propagation certainly has a place where plants are needed in large quantities for mass planting. Most horticultural varieties are of hybrid origin and their seedlings will vary in form, size and color. For naturalizing, this feature of seed propagation may be desirable. Iris breeders capitalize on the variation of seedlings in the develop¬ ment of new varieties.

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A major objection to propagation by seed is the time factor. Lou¬ isiana iris seed require a minimum of several weeks before germina¬ tion, but if not properly handled may require a year or more. Even after the seed have germinated, it is usually the second year before they produce their first bloom. Most of us are too impatient to wait this length of time.

Arceneaux1 has established that seed germination can be hastened by harvesting the seed when the pod is still partially green and before the seed have developed their full ripe color. If planted immediately after harvesting a high percentage will germinate with-

xArceneaux, George; Breeding and propagating Louisiana Irises. Bull. Am. Iris Soc. No. 82. pp. 67-71, July 1941.

Young seedlings are pricked off. [15 }

in a few months. This discovery has done much to speed up the slow process of seed propagation.

The actual planting of the seed may be done successfully in a number of ways. It is usually easier to plant the seed in a small container and transplant the seedling than it is to plant directly in a bed. By so doing, the problem of weeding is reduced. Further¬ more, seed planted directly in a bed may be washed away by heavy rain.

A method the writer uses in breeding work is to plant all seed from a single pod in a gallon size tin can that has been punctured for drainage. A mixture of four parts of leaf mold and one part of sand is placed in the can to within two inches of the top. The seed are broadcast over this and then covered with another half inch of the same material. A number Avhich designates the cross is painted on the can and a label giving the cross is inserted. The cans are then watered and placed in a cool location. They are kept moist until germination ceases.

As the seedlii^^ emerge, they are pricked off. Care is taken not to sever the seed ifSm the new seedling or to damage the roots. Then the seedling eithey is pitted or placed in a special bed where it re¬ mains until large enough to plant in the garden.

Vegetative Propagation

Vegetative propagation is by far the most popular method of in-

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creasing our iris plantings. There are three phases of this type of propagation. All three phases produce plants which are exactly like the varieties from which they were propagated. The three ways by which Louisiana iris may be propagated vegetatively are by rhi¬ zome separation, by rhizome cuttings, and by off-shoots from the flower stalks. This last method of propagation has not yet been perfected, but it is felt advisable to release the facts gained in pre¬ liminary experiments.

Rhizome Separation

In nature Louisiana iris propagate vegetatively by rhizome multi¬ plication. Natural increase is surprisingly fast, but its speed can be accelerated by taking advantage of the total mechanism with which nature has provided the rhizome. Under natural conditions a rhizome which forms a bloom stalk will usually produce two side rhizomes. These will bloom the following year, and in turn will produce more side rhizomes. The writer has observed as many as

[16]

Here rhizomes are separated.

seventeen side rhizomes formed on a single stalk. If the side rhi¬ zomes are not removed, the old rhizome usually rots. However, if the side rihzomes are removed and the old rhizome is replanted, there is an excellent chance that it will produce more side rhizomes before rotting.

The separation of rhizomes may be done any season of the year. If it is done immediately after the plant flowers, the old rhizome has a better chance of producing more side rhizomes. The only ad¬ vantage of dividing the rhizomes in the spring is that the old rhi¬ zome is less apt to rot if the side rhizomes have been removed. The ring-like scars along the rhizome are loci where leaves were formerly attached. Since a bud exists at the base of every leaf there are buds located at each ring-iscar. Single rhizomes may have twenty-five to fifty such buds. All side rhizomes develop from the buds located at

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A portion of the rhizome sends out new shoots. Two on left are ready to he pricked off.

the leaf scars. Theoretically the number of new side rhizomes an old one can form is limited only by the number of ring-like scars. In actual practice the theoretical maximum can be closely ap¬ proached if not actually reached by following a few simple practices.

Rhizome Cuttings

A rhizome planted in soil or other media will tend to produce new shoots. This tendencj^ is increased by removing the growing end. If the growing end is cut to two and one-half inches long, it will be sufficiently large to produce flowers the following season.

The piece of rhizome left, after removing the growing end, should be cut into sections approximately ;two and one-half inches long. These should be planted and kept moist but not wet and should be

[18]

placed in a cool, shady place. In time, new side shoots will develop. When they have reached a height of about four inches, the rhizome section should be carefully dug in order not to destroy any new roots. The new shoots may then be carefully pricked