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Friends of the Arboretum Newsletter

Number 8

August 1983

J. C. Raulston

Contents Page

  • Announcements and Coming Events
  • Observations and Arboretum Notes
  • People News
  • Guidelines for Your Fall Tulip Planting
  • A Conifer Synopsis
  • Book News
  • New Catologs and Plant Sources of Interest
  • New Plants Received in the NCSU Arboretum (now the JC Raulston Arboretum) - April-July 1983

Greetings and a welcome to a very special and unique newsletter issue - not only chock full of goodies - but it is also my first time to make an announced publication date - truly remarkable! I'm changing the format a bit and putting the announcements here at the beginning as many have told me it takes so long to wade through all my verbose ramblings that half the events are over before they get to them! So - first a look ahead - and then a review of recent arboretum news. It's a long story this time - but then you've got until January to read it all.

Announcements and Coming Events

NIGHT COURSE - Once again this fall Bryce Lane will offer his excellent and popular course Plants for Home and Pleasure (a general home gardening course) on Wednesday nights 7:00-8:40 beginning August 31 and continuing 15 weeks into December. It will meet in Room 125 of Kilgore Hall. Enrollment may be handled through the Division of Continuing Education at the NCSU McKimmon Center on Western Boulevard.

SEPTEMBER 17 - AUTUMN ARBORETUM SOCIAL - On Saturday, September 17 at 4:00, we will have a tank of ice-cold watermelons at the Arboretum to cut and share. We'll also walk and look at the new garden additions - plants, facilities, programs. There will also be a swap and give-away table - bring extra plants, cuttings, divisions, from your garden to trade or give away; or plants you'd like for others to see. (Anyone game for a seed-spitting contest?)

SEPTEMBER 18 - PUBLIC LECTURE - On Sunday afternoon at 3:00 PM, I will be presenting a free lecture on Great Gardens of the East Coast at the N. C. Museum of Natural History. It will cover the features of many gardens from Fairchild Tropical Gardens in Miami to Asticou Gardens in Maine.

OCTOBER 1-2 And NOVEMBER 5-6 WEEKENDS - THE "MAMMOTH PERENNIALS RE-PLANTOUT" - The huge perennial border planted this spring will undergo a complete replanting to perfect the design for better color display, sequence of bloom, arrangement of heights and to incorporate new plants. It will take an enormous amount of help and we'll be having student workdays on those 4 days from 9:00-4:00, and anyone interested in perennials or in just helping would be most welcome. (P.S. - many of the perennials must be divided and thinned, and we'll need good homes to send the extra plants to.)

OCTOBER 8 - DWARF CONIFER DAY - This is a second scheduling of the program which was announced in the spring. It will be an all-day program consisting of a slide lecture on dwarf conifers and great collections of them in various arboreta around the world, followed by tours of 4 excellent dwarf conifer collections in the Triangle area. Registration for the day is $10 which will include transportation and lunch. Please call my secretary, Emily Tate, (919-737-3132) to reserve your place and obtain information on where to meet - registration will be limited to not overcrowd the private gardens to be visited.

OCTOBER 13 - FRIENDS OF THE NCSU Arboretum (now the JC Raulston Arboretum) SLIDE SHOW - On Thursday evening at 8:00 PM in Room 159 Kilgore Hall, I'll present a slide show on plant and garden highlights of the spring and summer of 1983 including my early summer visits to PA, NJ, and CT gardens; summer tour of Minn, Wisc, and Chicago gardens and German gardens including the IGA show in Munich. We'll also have our fall plant distribution with several extra-special "goodies" this time.

NOVEMBER 5-6 - PERENNIALS WORKDAY - See October 1-2 announcement above.

NEXT NEWSLETTER in January. Enjoy the fall - visit the arboretum often - many plants have dazzling fall color which may individually last only a short time and repeat visits help catch the variety available - the Japanese maples (Acerpalmatum cvs.), smoketrees (Cotinus), Chokeberry (Aronia), Sweet Gums (Liquidambar), Sumacs (Rhus), and Barberries (Berberis) are particularly nice. Also the autumn fruit and berries make their great show. Take someone who has never been there and share the many treats of the garden.

Observation and Arboretum Notes

On one hand the April-July period has been full and busy as usual, on the other hand, some expected activities were changed and less than hoped for was accomplished. My scheduled group tours to DC-NYC and Germany fell by the wayside as I got tangled up with some doctors for some unexpected throat surgery and spent a month resting a little more than I'm accustomed to. Thankfully, all went well, I recovered very rapidly and am back 100% now. Will Hooker took the fine group on the DC-NYC tour for me and they hit the best spring in decades at its very peak. Everyone enjoyed the trip so much and such camaraderie developed that the group had a "reunion" picnic at the arboretum in July to renew the acquaintances that developed during the trip.

I managed only one trip out to visit gardens and collect materials but it was a dandy. After driving through Richmond on the Interstate bypass for 20 years and never stopping for a visit - I finally learned what grand things I had been missing as B. Townes of Wilkes Community College gave me a royal tour. Most of my visit was to a variety of private gardens and estates. One was a 5 acre property developed roughly 50 years ago by a rhododendron hybridizer. To properly prepare for rhododendron culture he covered most of the property with imported German peatmoss to a depth of 1"! He built an incredible collection of rhododendrons through importation of species and exchange with the noted American hybridizers of that period. In addition - over 1,000 cultivars of azaleas were planted, dwarf conifers, Japanese maples and many other choice plants (e.g. - I saw the extremely rare Elliottia for only the second time in my life; and my first time to see Stewartia malachodendron in bloom - 5 plants 15' tall in full bloom covered by the spectacular large white flowers with snowy purple stamens). The estate went into decline but over the past few years it has been brought back to its former glory and the present owners are propagating and selling many cultivars of rhododendrons rarely in commercial trade (only at the house - no mail order). If you are seriously interested in rhodys and azaleas and are passing through Richmond, a stop is well worthwhile (Mr. & Mrs. Jack Wyatt, 6311 Three Chopt Road, Richmond - 804/282-3846).

(While I'm on rhodys, I must digress for 3 notes.) (A) In visiting a fine collection in N.C. this spring I finally saw a cultivar in bloom I had long heard of - and am delighted to report it is as superb as reported. "Trudy Webster" is truly magnificent with excellent foliage, enormous trusses a good 10-14" in diameter of pale pink flowers 4-5" across. Well adapted to N.C. use. (B) After driving by within 200 yards of it for 7 years, I finally stopped to see the beautiful Vanlandingham Glen of rhododendrons on the campus of UNCC in Charlotte - well worth a stop in May to see acres of 8-15' tall rhododendrons in a woodland setting. (C) A secondhand (and unverified by me) story on rhodys came from a man who had spent years living and working in Nepal and was very familiar with the plants there. He said that he discovered a spot in N.C. comparable in "feel" to the rhododendron forests of the Himalayas and as spectacular as most in the British Isles. The place is the Knapdale Nursery near Parkton, N.C. which was apparently planted with over 60 acres of rhododendrons many decades ago and though many have been sold and the acreage has decreased, there are still some 20 acres of rhodys now up to 20' in height t }{\f13\fs20\ulw Attention Conifer Crazies!}{\f13\fs20 Two notes of interest for you. (A) In the fall a gathering of 32 conifer specialists was held at the home of Joel Spingarn in NY and from this meeting a new plant Society has developed - The American Conifer Society - with a goal to popularize dwarf conifers. To become a charter member one can send a check forrested in record sized trees - a National Register of Champion Trees of the U.S. is available for $3.00 from National Registry of BiI've ever seen; enormous old magnolias, many others. There is also a rather fine example of classic Italian Renaissance hillside garden with stone terraces and a water cascade. A Japanese garden has been added in recent years but sadly lacks in finish detail work and much vandalism even though it does contain some fine individual specimen plants.

Then on northeast for 3 intense days of plants and touring with Steve Wheaton of Swarthmore and Tom Dilatush of Dilatush Nursery as my guides. Far too much to cover adequately but just a few highlights. I've been pushing Cornus Controversa as a potential new N.C. nursery crop based on literature and performance of plants in our collection - finally saw numerous old specimens in full bloom in the Philadelphia area - more convinced than ever of its desirability - truly spectacular. A wonderful private small backyard garden containing over 1,000 different perennials (walking drenched in a solid downpour of rain for an hour and a half - but such plants that who cares about rain!) - including an interesting bigeneric hybrid - Heucherella from a Heuchera x Tiarella cross. The finest Chinese Fringetree (Chimonanthus retusa) I've seen - in full bloom at Barnes Foundation - magnificent (and again, well adapted to N.C.). At the Henry Foundation a brilliant red clone of the N.C. Cross Vine, native S.E. azaleas in full bloom, Amsonias, honeysuckles, lupines, and magnolias. At the Morris Arboretum an excellent tour by Paul Meyer to see all the recent changes, restorations, and additions to the arboretum - superb garden sculpture, the beautifully restored rock cascade area, magnificent old specimen trees everywhere. On to New Jersey and the delight of Mr. & Mrs. Dilatush and their beautiful nursery and superb dwarf conifer collection. Tom is one of the most consumate plantsmen I've ever met - incredible knowledge of physiology, taxonomy, technical scientific literature - a day with him is like a semester immersion in technical training - made me aware of so much about plants and a wonderful person. The fine Rutgers University arboretum, then to the Bammboobrook and Willowwood collections (the largest Metasequoia I've seen - 80'; my first awareness of the delicate and beautiful blue-flowered shrub Sophora davidi - which should do well in N.C. and we now have; an incredibly fine fastigate Juniperus virginiana seedling perhaps 35' tall and 3' in diameter); to Skyland - "New Jersey's finest garden" - excellent wisteria, conifers and heathers. The tour concluded with a day in Connecticutt visiting the research plots of Dr. Sidney Waxman of U. Conn. His research involves dwarf conifers - the genetics of the inheritance of dwarf characteristics, propagation and cultural techniques. It was truly exciting to tour his acres of plantings and thousands of different conifer seedlings. Most of the work involves white pine and Canadian hemlock but many other species are also represented. I was able to obtain a 4' diameter dwarf pine of our arboretum (which completely fills the back of a VW!) and 2 specimen paperbark maples (Acer griseum) about 9' tall and 4" caliper which we'll get this winter and plant on either side of the entrance to the lath house. I was particularly overwhelmed by his block of dozens of 6-14' specimen Japanese Umbrella Pines (Sciadopitys verticillata) which he sells to nurserymen at $500-$1,000 apiece to pay for his research program - they were magnificent! One last stop on the return at Oliver's Nursery in Fairfild, CN (a retail-only garden center on my speciality nurseries list at the arboretum) - my first visit and I was thoroughly impressed. It is relatively small but handles a wide range of superior plants - fine conifers, rhododendrons, deciduous azaleas, broadleafed evergreens, perennials, wild flowers, and others. Display gardens showed landscape groupings of specimen plants and demonstration plantings - a wonderful rock garden with old dwarf conifers, a perennials bed, etc. The most extraordinary feature was their alpine and rock garden plants section - a first for me in an American retail nursery. They sold not only individual alpines in pots - but also constructed and planted trough gardens for people to buy completed plantings. The troughs varied from 6"x6" to 2'x5' and varied from a few plants in gravel to entire miniature gardens with rock outcroppings and dozens of species. Prices for the completed troughs varied from $50 to $300. (For those unfamiliar - "troughs" were once just that - a trough chiseled from solid stone to hold water for animals. Gardeners made holes in the bottom for drainage and filled them with an extremely porous soil mix perfect for growing alpines. Genuine troughs are rare , very expensive and extremely heavy. Today they are made from various mixtures which provide boxes that look like stone as they age - but are lighter and affordable. One such formula is: 2 parts Portland cement, 1 part sand, 1 part moistened peat moss, 1 part fine perlite, 1/4 part vermiculite - mix dry ingredients together - add water until a ball can be formed when squeezed - spread mixture over a box shaped form of chicken wire molds about 2" thick and allow to dry. Troughs may be any shape or size - generally about 6-8" deep - and drainage holes must be left.) Of course, I had to pick up a few more plants (including a beautiful groundcover broom - Cytisus) to fill the remaining nitches in my load of pots, ice chests with cuttings, divisions, etc.

Arboretum Notes

Fall - in dry climates palms can handle lower temperatures than in areas where rain may fall in crowns and freeze around the one growing point. This was beautifully shown by two Windmill palm (Trachycarpus fortunei) plants in the arboretum - one in the open and one in the visitor center (overhead cover but no temperature protection). It rained heavily all day and that night temperatures fell to 10 degrees Fareinheight (coldest of winter) encasing everything in ice. The covered palm survived and the one with the wet crown died. We also had severe damage on the large Agave which in previous winters had tolerated 10 degrees and lower with no injury at all - likely for the same reason. Incidentally - the hardiest palms for use in N.C. are the Mediterranean Fan Palm - Chamaerops humilis, Needle Palm - Rhapidophyllum hystrix and Windmill Palm - Trachycarpus fortunei. For best results they should receive shade during winter months and a roof overhang may prevent crown freezing. West of Charlotte in the town of Shelby there is an old planting of Windmill palms now about 16' tall which certainly have endured 0 degrees or lower temperatures over the years.

01/15/83 - Of our 40+ species of ferns in the lath house, the following remained evergreen all winter (is that redundant?): Christmas fern - Polystichum acrostichoides; Ebony spleenwort - Asplenium platyneuron; Common polypody - Polypodium vulgare; Evergreen woodfern - Dryopteris marginalis; Toothed woodfern - Dryopteris spinulosa; also Dryopteris atrata hirtipes, Dryopteris ludoniciana, Polystichum andersonii, and the most attractive one of all for winter garden appearance - Dryopteris erythrosora, the Japanese Wood Fern.

Weather is never dull when one gardens - this year the latest major snowstorm in history here - about 8" when daffodils and redbuds in full bloom - bizarre!

With winter low of about 8-10 degrees, and that for only a brief period of time during the winter, and rarely down to 15 degrees - this was the mildest winter in decades and allowed many marginal materials to survive that normally would not be expected to overwinter. Perhaps most surprising were the very tender Solanum jasminoides album, Eucryphia x nymansensis, Rhus interigifolia, Corokia cotoneaster, Berberis darwinii, and Edgeworthia papyrifera which survived. Other plants which lived that were somewhat unknown but expected to be marginal included Convolvulus cneorum, Rhododendron simsii variegata, Washingtonia filifera, Callistemon sieberi, Jasminum officinale, Myrica californica buxifolia, Podocarpus totara, Mahonia nevinii, Cornus capitata, Hebe cupressoides, Pachysandra stylosa, and Scirpus tabernaemontan zebrinus Shima-Futo.

But there were losses (you've alwats got to try something so marginal you'll be truly excited if it beats all odds and survives). Desfontainea spinosa from Chile, Damnacanthus indicus from the Himalayas, and Embothrium coccineum from Chile as examples. My biggest worry of the winter concerned a flat of my choicest new plants which were in the lath house to be placed in an overwintering house when the 10 degrees and ice period mentioned above unexpectedly hit. I didn't realize it was getting so cold until I heard the temperature on a weather report late at night. I raced to the farm and the pots and root balls were solidly frozen and I was certain I had lost all the best items of a year of collecting (roots are damaged with much less temperature drop than needed to damage tops - the reason container growers have to take extra overwintering precautions) - which depressed and nagged at me all winter. But they were moved to appropriate storage for the rest of the winter - and I was delighted when the Cornus kousa variegata, Magnolia macrophylla Whopper, and Cornus controversa variegata finally leafed out and began to grow. Too close for comfort!

04/03/83 (Easter) - Magnificent flower displays - 96 different things in bloom. Some unusual ones for this area - Neviusia alabamensis, Prunus Hally Jollivet (a superb plant - long flowering period, blooms when quite small, roots very easily from summer cuttings), Paw Paw - Asiminia triloba, Rhododendron Chapmanii x mucronulatum (first evergreen rhododendron to bloom - excellent), Trailing arbutus Epigea repens, Fothergilla gardeni, Enkianthus perulatus, Corylopsis pauciflora, Stachyurus praecox, Pachysandra stylosa. Two plants which were particularly outstanding for continuous bloom over a 4 month period were the heather - Erica Arthur Johnson and the tiny but wonderful Houstonia caereulea alba - no plant could produce more flowers longer in relation to plant size. New to me this year and now one of my favorite must plants.

A near disaster with a very late freeze like last year - predicted to hit 24 degrees with most plants in full leaf and actively growing. Tracy Segner drew on her girl scout training and with the assistance of the farm crew a irrigation pipe teepee covered with black plastic was built big enough to completely enclose the big cutleaf Japanese maple and a heating element was placed inside to raise the temperature - a mammoth task. On really rare plants - particularly some Magnolias - we mounded soil around plant bases so if the top was killed we might regenerate the plant by basal sprouts. Many areas were devastated that night - luckily we went only to 28 degrees and survived with no serious injury - but way too close for comfort.

Big spring accomplishments - (1) digging, dividing (both major difficult tasks) and moving the grasses collection to new location; (2) creation of the "Secret Garden" by clearing an area under the large Japanese evergreen oak, planting hosta and liriope and installing seats; (3) tearing out the entire groundcovers plots area, putting in wooden dividers to keep plants from growing into other plots, and replanting; (4) building planting beds in front of lath house for Ericaceous plants; (5) installation of the bronze memorial marker in the Southall Garden; (6) movement of the entire rose planting (for the second time in two years!) from the north side of the annual beds to the south side (my hindsight is far superior to my foresight). Many thanks go to the dozens of people who helped on these projects.

04/23/83 - Clematis montana rubens in bloom; another learning experience as 90% of visitors strongly dislike the bed of red and yellow Texas tulips at the visitor center (after we've done all the things to ensure they rebloom at lease 3 more years - sigh!); incredible bloom on hollies this year - full of bees; Prunus glandulosa and Stranvaesia davidiana dead of fireblight; peak of Viburnum bloom; Daphne Ruby Glow beautiful in flower; excitement to see the rare and difficult Kalmiopsis full of flowers.

05/03/83 - Exciting day - first flower bud opens on our Laburnocytisus adamii and it is the true chimera form with yellowish-pink flowers. Grafted wood can yield the Laburnum reversion so we're lucky. A very rare and remarkable plant and I bubble with excitement for days. First bloom on our 3 year old Cornus controversa - flowers cover plant - but no seed set later. Rhod. Holden impresses me as much as last year - beautiful. Iris tectorum album - like white orchids - exquisite.

05/27/83 - Bloom on: Erica tetralix Pink Star, Kalmia latifolia (peak), Genista pedunculata diffusa, Potentilla nepalensis Miss Wilmont, Jasminum parkeri, Gypsophila cerastroides, several Amaryllis, Bletilla stricta alba, Azalea Chinsayi, Siberian iris, Coreopsis Sunray at peak and a sheet of yellow 15' x 25' - wonderful, Cotinus spectacular this time of year for first time, Itea oldhamia, miniature roses at peak.

06/03/83 - Bloom on: Clinopodium coccineum, all deciduous hollies, Rosa gallica officinalis, Jasmine humile revolutum, Potentilla tridentata, Cornus kousa Summer Stars, Nandina Moyers Red - distinctly pink flowers - all others are white; Sapindus drummondi and Hovenia dulcis - first time to flower for both - 5 years from seed, Lilium Connecticut King - finest of lilies in collection - superb.

06/26/83 - Bloom on: Cyrilla parviflora, Clethra acuminata, Gordonia lasianthus, Agapanthus Peter Pan (about 2-3 weeks earlier than the species), Vitex at peak, Magnolias Royal Crown and Susan in rebloom, Erica cilaris Maweana and Stoborough.

07/05/83 - Very excited with seedlings emerging from plantings of seed from Chinese botanical gardens - several extremely rare or not even listed in the limited literature I have - Cercis chingi, Chimonanthus nitens, Phellodendron chinensis, Keteleeria evelyniana and Arisaema jacquemonti.