UNIVERSITY OF VERMONT
2010 SUSTAINABLE PERENNIALS RESEARCH
Dr. Leonard P. Perry
Extension Professor
Sites:
H=Horticulture Research Center, So. Burlington, USDA
zone 4b
Spring
2007 bulbs
| Perennial
trials listing (as of 2006)
photos: summer
1997
| 5/12/00
| 5/19/00
| 5/28/00
| 6/3/00
| 6/20/00
U=UVM greenhouses [view,
47K], Burlington, including outdoor student garden test beds,
USDA
zone 5b
photos: freezing
research
1997
M=
Perry's Perennials, Milton, USDA zone 4a
Winter soil
temperatures,
Summer
Soil Moisture, Sunflower trials 2000
| 2002
W=Waterfront
Park All-America selections flower display garden,
Burlington, USDA zone 5b
Current | Past
Studies
Controlled Freezing, Hardiness of perennials:
In 2008-09 a study began to examine various temperature regimes of
deacclimation during midwinter (January) for Sedum 'Neon' and Salvia 'Rhapsody in Blue'.
Treatments included holding at 34F, one week or two weeks at 55F,
one week of cycling between 34F and 55F, and one week at 40F.
In 2009-2010 the same deacclimation study will be done with two
additional perennials Achillea
'Apricot Delight' and Leucanthemum
'Becky'.
In 2009-2010 studies were begun on the hardiness of Heuchera (coralbells) cultivars,
particularly villosa hybrids
(funding courtesy of New Hampshire Plant Endowment). Plants were
frozen to the five usual freezer temperatures (-2,-5,-8,-11,-14C) on
two dates in January and March. Cultivars under study included
'Caramel', 'Mocha', 'Blackout', 'Frosted Violet', and 'Tiramisu.
(2009-2010
results)
New cultivar performance and hardiness trials:
Over 170 new cultivars are being evaluated in trials in USDA zone 4a
for performance, flower time and color, hardiness, pest problems, and
potential
for future studies or use in the region. This year we continue
as an official test site for new Blooms
America introductions
at 3 sites (USDA zones 4a, 4b, and 5a), with selections also from
Planthaven and
North Creek
Nurseries.
Annuals are also being trialled at the Waterfront Park in an
official
All
America Selections Flower Display Garden which also
include specialty
annuals courtesy of
DS Cole Growers
and Pleasant
View Gardens in New Hampshire. In 2008, trials were begun on
coralbells (Heuchera) field
hardiness.
Effects of composts and
fertility on perennials
In summer 2008, five perennials (Ice Dance Carex, Becky Shasta daisy,
Brandywine foamflower, Apricot Delight yarrow, and Biokovo geranium)
were
grown in various combinations of a commercial compost medium, with
synthetic and organic liquid fertilizers, to monitor any labor savings
(watering, fertilizer) and plant growth. (funded by Perennial
Plant
Association)
In summer 2009, six perennials (Ice Dance, Becky, Bevans geranium,
Rhapsody in Blue salvia, Brandywine, and Caramel coralbells ) were
grown with three fertilizers (2 rates of a 4-3-2 organic poultry
product and Nutricoat) and two media (ProMix BX as a control with a new
cow manure based product from Vermont
Organics Reclamation also with coffee wastes and perlite 4:1:1
v:v:v) to determine possibility of the latter medium for production.
Past Studies
Shrub rose evaluation (H,M):
Over 5 dozen cultivars of shrub roses (list
and characters), emphasizing new series such as the Parkland,
Meidiland,
Explorer and David Austin ones, were evaluated among these sites and
in cooperation with the University of Maine (Dr. Lois Stack) for
hardiness,
performance and disease resistance (rose
ratings (updated 9.05) article on top
15 rated to date).
photos: June
2003,
north side | June
2003, inside
New cultivar performance and hardiness trials (H,M):
Emphasis in the past of the hundreds trialled was on
perennial geraniums (spring
observations) (2001-2002
observations) (photo
7/01), monarda including new Dutch cultivars,
Tiarella, Heuchera,
Pulmonaria, and potentially hardy epimediums.
Hardiness of Low Groundcover Plants:
In 2007-2009 hardiness studies (funded by the New England Greenhouse
Conference and New England Grows) involved the hardiness in 4-inch pots
of 33 Steppables (courtesy Quansett Nurseries) and Nooks and Crannies
(courtesy DS Cole Greenhouses). (final results of field
and controlled freezing studies)
Controlled Freezing, Hardiness of perennials (U):
Several dozen perennials over several years are being frozen in
controlled
chest freezers to determine root killing temperatures; effects of cold
intensity, duration, cycling, and rate of drop. These included heathers
(Calluna) during 2001 and 2002.. Other freezing
studies examined
various temperature cycling and rates of drop, and the effect on
hardiness
of dianthus, foamflower and perennial geranium. These latter were part
of the M.S. thesis research of Cheryl
Bruce (see abstract
and slide
show)
and Andrea
Luchini
(2003 results
, summary,
thesis
abstract, and
slide
show). Results of these, and studies of previous grad
students, are
summarized in leaflet
COH31.
In 2004-2007 hardiness studies (with assistance of grad student
Sarah
Kingsley Richards) involved effect of soil moisture
on 3
cultivars of sedge (Carex); effect
of plant age (fall potted,
year
old, 4-inch pots) on winter survival,
3 cultivars; hardiness in pots of select Steppables (low
groundcovers).
Shrub rose evaluation (H,M):
Over 5 dozen cultivars of shrub roses (list
and characters), emphasizing new series such as the Parkland,
Meidiland,
Explorer and David Austin ones, were evaluated among these sites and
in cooperation with the University of Maine (Dr. Lois Stack) for
hardiness,
performance and disease resistance (rose
ratings (updated 9.05) article on top
15 rated to date).
photos: June
2003,
north side | June
2003, inside
Effect of soil moisture on hardiness
monitoring field soil moisture, and the effect on freezing of wet or
dry watering regimes (below 10% and above 20% soil moisture content) on
3 cultivars (funding by the NH Horticulture Endowment); first
year summary, first year photo Astilbe
dry, Astilbe
wet (second
year results forthcoming)
Overwintering Covers
New overwintering fleece cover in various layers on 20 cultivars,
including
a sandwich of straw between white poly layers, and one or two layers of
fleece (thick felt material) with and without a white poly covering
(funding
by New England Greenhouse Conference; plant donations courtesy of Creek
Hill Nursery, PA), compared with same cultivars under controlled
freezing.
Performed 2003--04, 2004-05. Results forthcoming.
Photos: before
covering fall 2003 | after
covering 2003 | before
2004 | after
2004
| close-up
2004
Media and fertility
Three cultivars (Hemerocallis Stella d'Oro, Geranium
'Max Frei', Dianthus 'Arctic Fire') were potted in
12 combinations
of media and fertility to observe effects on growth after one
season.
Media include commercial peat-lite, local organic, and German peat-lite
products. Fertility include organic liquid, standard liquid,
and
new color-coded Osmocote products.
Fertility
and media 2003 results | Fertility
and media 2004 results
Powdery mildew studies (U):
New cultivars (15) of beebalm were
established in 1998 (H) for evaluation
for genetic resistance to powdery mildew in a randomized complete block
design. Plants were evaluated for drought, weed and cold stress early
2000,
then potted for subsequent mildew studies at the UVM greenhouse (U).
Due
to poor growth in pots, plants were put into field studies in Milton in
2003. Plants will be dug, divided, and potted this year for continued
trials in pots.
During 2000 and 2001, 5 organic controls
were tested on Snow White bee
balm (see article below) in containers (U). In 2003 a study with Phlox
pan. Mt Fuji was established to look at the effect of salt and milk
solutions
on mildew, as have proved effective on grapes and vegetable
crops.
Beginning in 2003, 24 new cultivars of
garden phlox will be compared
in a randomized complete block design for resistance to powdery mildew
in field studies in Milton. (8/03
photo). No results were obtained this first year, due to poor
mildew
pressure, with the study to be repeated in 2004.
[Slide
Show on
past studies of powdery mildew on phlox and monarda.]
1998
Scientific
article on powdery mildew among bee balm cultivars
1999
Scientific article
on organic powdery mildew controls on phlox
2000
Scientific article
on organic powdery mildew controls on bee balm
Article
on
Bee Balm cultivar stress results
Powdery
Mildew
on Phlox and Monarda leaflet(new 12/01)
Powdery
Mildew
Controls on Phlox and Monarda leaflet (new 12/01)
New England Aster cultivar rust resistance (U):
About 15 cultivars of Aster novae-angliae were established for
evaluation
for genetic resistance to rust in a randomized complete block design in
the field. After two years of defoliation due to lacebugs,
plants
were potted and moved to the UVM greenhouse. With poor growth
in
pots, plants of the 12 cultivars were subsequently planted in
randomized
complete block field studies in Milton in 2003 with data obtained late
in the a season (2003
rust
article). Data were not available since due to
minimal rust and subsequent browsing by deer and groundhogs.
Lilac
Evaluation
(M):
Okay, they're not herbaceous perennials, but are effective in our
climate
used in combination with them, and a key shrub in Vermont.
This evaluation
over many years of over 230 varieties emphasizes bloom and disease
resistance,
with many photos and a table of blight resistance observations.
Ornamental
grass hardiness (H,M, U)--1999 data:
At 3 sites in the Champlain Valley (USDA zones 4a, 4b and 5b), at least
2 dozen cultivars of ornamental grasses were evaluated over a five year
period for winter hardiness, as well as other landscape features. Many
are recent introductions to the U.S. from Germany including new ones
this
year. Results were included with those from an extensive collaborative
national effort.
Appreciation is expressed to New England
Grows; New
England
Greenhouse Conference; Vermont Nursery and Landscape Assn.;
New Hampshire Horticulture Endowment; Perennial Plant Association;
Greenleaf,
Sunny Border, North Creek and Dunvegan nurseries; UVM Extension;
VT Agr. Experiment Station. Thanks to
Burlington
Parks and Recreation for assistance and making possible the Waterfront
Park display beds.