Summer Annuals Trial Report
North Carolina State University
Raleigh, North Carolina
Robert E. Lyons
Professor and Director
With Technical Assistance from Bernadette Clark and Cindy Lambert
Department of Horticultural
JC Raulston Arboretum
Horticultural Research Series No. 153
Introduction and Cultivar Evaluation Criteria
The Annual Trial Gardens at NC State Univesity are located within the JC Raulston Arboretum, 4301 Beryl Road, in Raleigh. The JCRA is an 8 acre site administered by the Department of Horticultural Science and located on latitude 35° 47'N, longitude 78° 42'W with an elevation of 400 feet.
Seedling and vegetatively derived plants were grown to transplant size in 2.5 inch x 2.2 inch containers, with most planted outdoors on 26 April 2001. The remaining selections were planted shortly thereafter when transplant survival would be best. Plant spacing in the trials was 18 inches x 24 inches (in-row x between-row spacing). Seven plants of each entry were used to evaluate landscape performance. Plants were rated weekly as described later in this report.
We gratefully acknowledge the support by Fafard, Inc. (P.O. Box 26, Anderson, SC 29622), Dillen Products, P.O. Box 738, Middlefield, OH 44062, The Scotts Co., 14111 Scottslawn Rd., Marysville, OH 43041, and the North Carolina Commercial Flowers Growers Association. The assistance of Cindy Lambert, Ingram McCall, Bradley Holland, Mitzi Hole, Valerie Tyson, Chris Glenn, and Robbie Wooten is acknowledged with much appreciation!
Hoffman Nursery <www.hoffmannursery.com> of Bahama, NC, and Lakeview Gardens (Ralph Repp) of Waynesville, NC, donated selected ornamental grasses and sun coleus, respectively, for our specialty display beds...thanks!
We are especially thankful to other departmental staff and the volunteers of the JC Raulston Arboretum who assisted in transplanting and maintaining the annual beds throughout the growing season....we couldn't have done it without you all!
Robert E. Lyons
Professor and Director
Horticuture Research Technician
Sources of Seeds and Plants (12/14/01)
AAS – All-America Selections,
1311 Butterfield Road, Suite 310, Downers Grove, IL 60515-5606
BALL – Ball Seed Co., P. O. Box 335, West Chicago, IL 60185
BCG – Bear Creek Gardens,
P. O. Box 9100, Medford, OR 97501
BEN – Ernst Benary of America, Inc., 1444 Larson Street, Sycamore, IL 60178-9705
BFP – BallFloraPlant, 622
Town Road, West Chicago, IL 63185
DHN – Daehnfeldt Inc., P. O. Box 38, N. Manchester, IN 46962
ECKE – Paul Ecke Ranch, P. O. Box 230488, Encinitas, CA 92023-0488
FIS – Fischer USA, Inc.,2995 Wilderness Place, Suite 102, Boulder, CO 80301
GOLD – Goldsmith Seeds, Inc., 2280 Hecker Pass Hwy, Gilroy, CA 95020-1349
GRS – Grimes Seeds and Plants, 11335 Concord-Hambden, Concord, OH 44077
HOFF – Hoffman Nursery, 5520 Bahama Road, Rougemont, NC 27572
LVG – Lakeview Gardens, 423 Country Rd., Waynesville, NC 28786
PA – PanAmerican Seed Co., P. O. Box 438, West Chicago, IL 60185
PK – Park Seed Co., 1 Parkton Ave., Greenwood, SC 29647-0001
SAK – Sakata Seed America, Inc., P. O. Box 158, Wrens, GA 30833
SYN – Syngenta Seeds, Inc., 5300 Katrine Avenue, Downers Grove, IL 60515-4095
T&M – Thompson & Morgan, 220 Faraday Ave, Jackson, NJ 08527-0308
We also gratefully acknowledge the support by Fafard, Inc. (P.O. Box 26, Anderson, SC 29622); Dillen Products, P.O. Box 738, Middlefield, OH 44062; The Scotts Co., 14111 Scottslawn Rd., Marysville, OH 43041; and the North Carolina Commercial Flowers Growers Association.
Summer 2001 Annual Trials
Pertinent Weather Data
Understanding Our Data
Plant Height & Diameter
at Maturity (in inches)
This measurement is taken near the end of the entire evaluation period.
Number of Weeks in Flower
Recorded as the total number of weeks in flower throughout the entire season. This should give you an idea of whether or not a plant is best used for the whole season or as a "fill-in" for special displays. Obviously, those species grown for foliage interest, e.g. Duranta erecta, alone will score poorly in this column!
Plants were given a visual rating weekly by the same person beginning May 29, 2001 (three weeks after planting) through September 17, 2001 (16 weeks of observations.) The rating was based on plant performance and appearance, including floriferousness, plant size and shape, and freedom from insect and disease problems. The rating scale ranged from 1 (very poor) to 5 (excellent), with 0.5 unit increments; a 0 rating indicated that all plants of the cultivar trial died.
Summaries of Weekly Ratings
Realizing that there are many species/cultivars which may do better in one part of the growing season versus another, we provide an "early season average" and "late season average" for each entry. The former is the average of the first 8 weeks of the evaluation period and the latter includes only the last 8 weeks. This information may be useful in planning short term plantings with high impact as well as for studying temperature preferences, life cycle changes, and/or the impact of photoperiod on plant performance. The "number of weeks rated above 3" gives you an idea of how consistently throughout the twenty weeks an entry is an exemplary performer.
The Lists In This Report
We list each of the above statistics (except the weekly ratings themselves) in all the reports that follow:
"The Top 10" – this list shows the species/cultivars with the top ten "All Season Averages." These were our top overall performers.
"Leaders of the Pack" – lists all species/cultivars with an "All Season Average" of 3.0 or better. We consider this the cutoff rating for a "significant performer." This list shows all your best choices for planting, listed by plant name.
"Leaders of the Pack – Early Season" – this shows entries with "Early Season Averages" of 3.0 or better based on the first 8 weeks of evaluation. This group may prefer cooler temperatures or only have a relatively short ornamental life, and might not show up on the "Leaders of the Pack" list above.
"Leaders of the Pack – Late Season" – this shows entries with "Late Season Averages" of 3.0 or better based on the second 8 weeks of evaluation. They may prefer very warm temperatures or flower as daylengths start to shorten, again precluding them from inclusion on the overall "Leaders of the Pack" list.
"Best of Breed" – shows the best performing cultivars in each species.
"Summary by Series" – groups the information for cultivar series where appropriate. This can be a quick reference for related cultivars as well as a handy tool to judge the general performance of an entire series offered by a breeder.
Want Additional Copies of this Report? Visit our Website!
"Off the Cuff"
Summaries of Casual Observations from the Field Staff – Summer 2001
In this section you'll find summarized comments from those we recorded throughout the growing season......kind of like a "between the lines" addition to the actual ratings found in this report. Our comments are in alphabetic order according to species; this list is not exhaustive since not all species received particular comments.
From past experience, we have found that the heat of the Raleigh's summer is no friend to these plants. Flowering generally declines and disappears completely soon after the spring temperatures warm up permanently; 2001 was no exception. However, of all cultivars examined, 'Maggie' proved the best in returning to a "close to spring" form for floriferousness. An interesting note, we found the flowerless, dense clumps of foliage in midsummer to be attractive complements to the garden in spite of their lack of flowers.
We are very excited about the growing potential of the 'Dragon Wing' begonia hybrid. It was far exceeding the performance of traditional wax begonias in early July and maintained that pace into September. It is truly a breakthrough in its group with, in our opinion, fabulous potential for landscape use in our climate.....pink or red, makes no difference, satisfaction almost guaranteed! By mid-August, another standout was 'Olympia Sprint White'. As usual, the tuberous begonias were the laggards for performance value in this climate, barely eking out any semblance of respectable display....but we're happy to keep trying them even though we can probably predict their evaluation numbers!
This year we went "off the boards" and brought in about 30 different sun coleus cultivars from one of our own state breeders/growers Ralph Repp...what a great move. Devoting an entire bed to these wildly up and coming landscape ornamentals made for a spectacular display. Most grew vigorously and stood out boldly in the beds. What were some of our favorites? Try 'Pineapple Prince', 'Eclipse', 'Florida Sunrise', 'Marie', 'Inky Pink', and the strangely tight and linear 'Dragons Claw'.....the last one has an erect stature with narrow and fluted foliage that is a deep purplish red.....neat and unusual.
I really want to like Cosmos 'Cosmic Orange' but it is doing its best to deny me that pleasure! The early and late season averages for this cultivar were poor, leaving it with a dismal overall rating for the season. Fast to flower and fast to seed seem to characterize this cultivar, barely giving us a chance to enjoy its brilliant flowers and short stature.
We placed this fascinating foliage-based plant out in a long border this year and did it ever attract attention. Its lovely green and cream leaves accented other garden colors, enhancing their visibility. Duranta erecta is easy to propagate from cuttings and freely branches after a little pinching at planting. We like it in spite of those pesky thorns found occasionally along its stems!
The Raleigh summer can be tough on geraniums. Our plants were much improved this year, given the renewed attention we paid to deadheading and the assistance provided by Mother Nature's more agreeable temperatures. Once again, the 'Fantasia' series surfaced to the top, sporting all season averages from 4.1 to 4.4.....respectable indeed! If I had to mention some "runners up," I would include, 'Designer Hot Coral', 'Galleria Sunrise Improved', 'Maverick Light Salmon' and 'Maverick Pink'.
Our New Guinea impatiens jumped to the forefront early in the season. By July 3, my personal notes indicated the 'Sonic' series to be real standouts. By the middle of August, we noted the seed-derived cultivars inferior to those vegetatively reproduced....generally speaking, the vegetatively propagated cultivars are much more interesting. We are still raving about the cultivar 'Celebrette Light Coral'. This year we placed it in a long border where it received much more sun than we'd normally be comfortable with. It shined! Strong and diverse foliage colors, excellent flower display, and a uniformly mounded habit contributed to another excellent year for this cultivar. I recommend it highly!
No surprise to anyone, 'Tidal Wave Silver' was a true standout in color and form. We heartily endorse this cultivar for its strong flowering ability and landscape coverage. One big surprise to us was the appearance of a new contender for 'Purple Wave'.....we noticed by midsummer that 'Trailing Purple' might just be the one to dethrone 'Purple Wave'. The numbers proved our visual observations right as the former scored a Late Season Average of 4.6 and the latter came in at 4.1....we'll keep an eye on this rivalry! Other noteworthy cultivars were 'Ramblin Peach Glo', 'Misty Lilac Wave' and 'Surfinia Giant Purple'. And for the historical reference record.....I remember when the 'Fantasy' series was released and the initial show was great. Unfortunately, it had a tendency to fade away, even earlier than other cultivars......same thing is still happening here. Oh, well, time for triple deadheading!
Oh, my, were the Yubi's great or what?? It was easy to overlook the somewhat bothersome behavior of afternoon flower closure when the colors were so electric. Strong growth throughout the season, prolific flower production, and high end ornamental value were the obvious keys to the notoriety of this cultivar series. We hope these become popular and widely used....stop worrying about getting only a half day out of them,their abbreviated display more than makes up for that!
You don't have to ask, this genus is one of my personal favorites! It is no surprise that I brought in a somewhat new cultivar to look at, 'Chim Chiminee', that was receiving a lot of attention in catalogs. Unfortunately, it didn't live up to expectations. I'm delighted to see this native N.A. species used more and more but this cultivar seems to have been released prematurely. The plants were hardly uniform in almost every respect. Colors were irregular, flower types ranged from the familiar flat-rayed and wide to the advertised narrow and almost tubular in appearance. I'm all for mixes but this batch showed way too much to be acceptable....send it back to the selection fields and come back later!
By August 15, our S. splendens were declining fast. This was a disappointment given that we were able to employ judicious deadheading this year.
An interesting phenomenon popped up when comparing the entries here. The first half of the season accolades went to the 'Tapien' cultivars with their rating of 4.4. By the end of the season, performance flip-flopped when the 'Aztec' series jumped ahead. Bottom line, both are great series and represent the true stars of the genus; I'm afraid these ground cover types are all but knocking their upright cousins out of the competition for landscape performance.
So far, it appears that violas are still better grown and marketed for winter color in the Raleigh area.....their summer performance was indifferent at best, often bordering on completely unacceptable.
Hands down, these 'Profusion' zinnias looked excellent....again. I think this is a real breakthrough in zinnia breeding. To really put them to the test, we placed them immediately next to some traditional zinnias, which were sure to get powdery mildew, but the Profusions remained clean and sharp. Our periodic deadheading helped maintain their appearance, too. Highly recommended. Bring on more colors!
Odds & Ends
Each year we place some "unsolicited" species and cultivars throughout our trial beds. This year, some exceptional standouts included several vegetatively propagated plants. Saccharum officinarum 'Peles Smoke' was notable and recommended. It's tight, erect stature, dusty purple color, controlled growth rate, and bold foliage made for a lovely specimen plant in the back border. It reached 6' – 8' tall easily but had strength and durability unlike other tall, grass-like ornamentals. Pennisetum setaceum 'Eaton Canyon' is a dwarf form of the VERY popular P. s. 'Rubrum'. 'Eaton Canyon' is about half the height and a nice alternative but it just didn't flower as much as its cousin. It also tended to be less full and dense....but we still liked it.
Each year our summer trials include some snapdragons and pansies, along with a few other species which have historically done poorly in Raleigh's summer heat. We would be happy to continue what appears to be an annual futile exercise but I really don't see much change in the behavior of these cool species. Is it time to accept this fate with the understanding that we now have more "color" options than ever so as to not consider the cooler species for hot summers? I guess I'm thinking out loud here but I'm just not seeing a place for the elusive "summer pansy" in our area.
"One of a kinds" which are worth a look, at least as far as they performed for us, were Cuphea llavae 'Tiny Mice', Capsicum annuum 'Chilly Chili', Sanvitalia procumbens 'Aztec Gold', and Fuschia 'Snowfire Angel Earrings'.