copy of Alberta Perennial Trial Garden Evaluation 2006-2008

Project Protocols
The Alberta Perennial Trials introduces approximately 50 new perennial varieties and cultivars annually
to the project. Plants are evaluated over three seasons with a total of approximately 150
varieties/cultivars under evaluation in any given growing season. In most cases plants are supplied in
sufficient numbers for each site to evaluate a minimum of five to six plants of each type. Reports are
published annually. This report contains the results of the 2006 – 2008 series of plants.
A mandate of the project is that growing conditions should reflect those encountered by home gardeners.
Planting beds were amended with organic matter prior to planting, no additional fertilizers were applied.
Soil tests were collected to ascertain baseline growing conditions. A low maintenance regime was
followed including irrigation and weeding as required and cultural methods to control pest and disease
problems. Staking and deadheading for the first two growing seasons was limited to half a plant
grouping, the other half were left alone to evaluate performance without these activities.
The perennials were planted in late June 2006 and condition on planting was rated. Data collected
throughout the growing seasons included: evaluation of winter survival; monthly measurements of height
and spread; weekly assessment of bloom; and ongoing monitoring for pests and disease. Plants were
evaluated for overall landscape appeal at the end of each growing season. Mitigating factors that may
have interfered with plant performance were also recorded. Plants that did not over winter were not
routinely replaced.
Weather data was collected from the appropriate Environment Canada weather stations. Appendix A
briefly summarizes weather patterns for the duration of the trial. Both Calgary and Olds received higher
than normal amounts of precipitation during the years of the trial. Most of the excess precipitation was
received during June in all three growing seasons. Test plots at Olds College suffered from severe
flooding during the first week of June 2008. Notes are provided in the Comments sections to indicate
where plant performance has been impacted. Overall the 2008 growing season was delayed at both
Calgary and Olds. Spring temperatures were colder than normal. The excess rain likely kept soil
temperatures cool enough to affect the emergence and growth of the plants. Plant growth noticeably
improved when soils dried out near the end of July. Peak temperatures for July in 2006 and 2007 were
slightly warmer than normal at all three locations. The Muttart site recorded lower than normal annual
precipitation for the duration of the trial. Beds were hand watered to mitigate the decrease in
precipitation.
Site Information
The Calgary Zoo test beds with the surrounding arboretum and plantings offers the most sheltered
location for plant material. Due to the sheltered location, presence of an irrigation system and good soil
conditions, overall survival rates were slightly higher than the other two test locations. Soil tests taken in
2008 showed nutrients and organic matter all to be within the normal range. Rodents (squirrels and mice)
caused damage to the crowns of some plants during the winter of 2006/07. Rodent damage was noted on
all Sempervivum cultivars throughout the duration of the trial. Leaf tier was a significant issue in 2008 for
the Delphinium collection. Finally, a minor irrigation break occurred in June of 2008, with minimal
impact to the collection.
The Olds College beds are semi sheltered by surrounding buildings. The shade bed skirts plantings of
trees and shrubs and some reduction in maximum growth of plants in these beds may be related to root
competition. Soil testing indicates low nitrogen but organic matter levels are adequate. The gardens
receive supplemental water from the irrigation system when required. Insect damage affected plant
vi
performance in some instances. Leaf tier damage to the Delphinium cultivars was significant in 2008.
The appearance and performance of Ranunculus repens ‘Buttered Popcorn’ was noticeably affected by
pest damage in 2008.
The Muttart Conservatory test beds offer the most exposed site for plant material. Compost and peat
moss were added to various sections of the beds to improve moisture retention and tilth. A slow leak in
an irrigation supply line in late 2006 resulted in boggy soil conditions in a small portion of one test bed.
Repairs were undertaken in spring 2007 and with a few exceptions there was no impact on the plants in
this series . Soil tests drawn in 2007 revealed low nitrogen amounts in the beds at the time of testing
however overall plant health and organic matter levels are satisfactory. Theft of some plant specimens
occurred in 2006 and 2007. Antitheft signs were installed in July 2008, reducing the incidence of theft
significantly.
Notes on Data
•
Cultural information noted in this document was collected from outside sources (see References).
Species/cultivars were compared to descriptions given in reference material to confirm the identity
of plant material.
•
Heuchera ‘Orange Man’ and Heuchera ‘Hercules’ were excused from the study due to very poor
condition of plant material upon introduction to the study.
•
The plants in this study were evaluated in each of the following categories:
Winter Survival
Ratio indicates the number of plants that overwintered/number of plants supplied to the project.
Bloom Rating
5 = 81 – 100% plants bloomed; 4 = 61 – 80% plants bloomed; 3 = 41 – 60% plants bloomed;
2 = 21 – 40 % plants bloomed; 1 = 1 – 20% plants bloomed; 0 = 0% plants bloomed
Average Maximum Height and Spread
The average of the maximum heights / spreads the group of plants attained at a location
Incidence of Pests or Disease
Name and year of incidence of pests and/or disease. Comment section provides further details as
required.
Overall Quality Rating
5 = highly recommended; 4 = recommended; 3 = recommended with limitations (may relate to hardiness issues or severe pest/disease problems); 2 = not recommended; 1 = failed due to unfavourable
conditions unrelated to hardiness
•
Plant measurements in this document are given in centimetres. The following table provides Imperial equivalents to frequently used metric measurements:
Centimetres
10
20
30
40
50
60
70
80
90
100
Inches
3.9
7.9
11.8
15.7
19.7
23.6
27.6
31.5
35.4
39.4
vii
photo not available
Gypsophila fastigiata ‘Silverstar’
lawn chamomile
Plant Form:
low mound
Foliage:
bluish-green linear leaves
Bloom Description:
airy panicles of tiny white flowers, blooms July and August
; fertile, well drained soil
Culture:
specimens supplied were small and sparse, plants sparse, emerged late and grew slowly,
mass plant for good effect, will rebloom later in the season if sheared after bloom, plants
competed at Muttart with invading quack grass
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
n/a
5
Incidence of Pests or
Disease
Overall Quality
Rating
Light Conditions:
Full Shade
2007
Olds College
2008
2/3
1/3
5
5
30 cm / 40 cm
2006
n/a
5
2007
Muttart Edmonton
2008
3/3
2/3
3
5
25 cm / 45 cm
2006
n/a
5
2007
2/3
3/3
5
5
30 cm / 40 cm
none
none
none
2
4
4
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
16
2008
Hemerocallis ‘Ruby Stella’
daylily
Plant Form:
vase shaped
Foliage:
medium green, long linear keeled leaves
Bloom Description:
close racemes on tall flower stems, trumpet-shaped bloom of ruby red, blooms mid June
to frost, repeat bloomer, smaller dainty blooms
; well drained soil, average fertility, tolerates a wide range of soil conditions,
drought tolerant once established but performs best with even soil moisture
developed by Anthony Tessleaar International, mid size dwarf form, everblooming, long
bloom period however blooms sparse at any given time
Culture:
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
Overall Quality
Rating
n/a
3
2007
Olds College
2008
5/5
5/5
5
4
65 cm / 100 cm
2006
n/a
0
2007
Muttart Edmonton
2008
5/5
5/5
5
5
60 cm / 90 cm
2006
n/a
1
2007
5/5
5/5
5
5
60 cm / 65 cm
none
none
none
4
4
4
Bloom Rating: 5 = 100% plants bloomed; 0 = 0% plants bloomed
Overall Quality Rating: 5 = highly recommended; 4 = recommended; 3 = recommended with limitations; 2 = not recommended;
1 = failed due to unfavourable conditions
Winter Survival ratio indicates the number of plants that over wintered successfully/number of original plants
17
2008
Heuchera ’Dolce Key Lime Pie’
coral bells
Plant Form:
low clump
Foliage:
basal rosettes of rounded trilobed leaves with scalloped margins, lime green turning to
chartreuse/yellow in higher light conditions, some amber fall colour
racemes of tiny white flowers, insignificant ornamental effect
Bloom Description:
; protect from afternoon sun, evenly moist but well drained soil, soil rich in
organic matter
developed by Terra Nova Nurseries, specimens supplied small, poor viability following
winter at all three sites, plant crowns appeared to be heaved out of the soil, may perform
better with winter mulch
Culture:
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
n/a
0
Incidence of Pests or
Disease
Overall Quality
Rating
Light Conditions:
Full Shade
2007
Olds College
2008
3/5
1/5
2
5
25 cm/ 25 cm
2006
n/a
0
2007
Muttart Edmonton
2008
4/5
0/5
1
0
15 cm / 20 cm
2006
n/a
0
2007
3/5
0/5
0
0
15 cm / 25 cm
none
none
none
3
2
2
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
18
2008
Heuchera ‘Frosted Violet’
coral bells
Plant Form:
dense mound with erect branched airy flower stems
Foliage:
basal rosettes of plum coloured leaves over silver green base
Bloom Description:
light pink buds, airy racemes of tiny white flowers, blooms July to September
Culture:
; protect from hot afternoon sun, performs best in soil rich in organic matter, moist
well drained soil
developed by Charles Oliver, includes native H. villosa in parentage, tolerates full sun,
crown of one specimen destroyed by mice at the Calgary Zoo, two specimens each at the
Calgary Zoo and Muttart appeared to be heaved out the soil after winter, the remaining
specimens were vigorous
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
Overall Quality
Rating
n/a
0
Olds College
2007
2008
5/5
5
2/5
5
2006
n/a
0
Muttart Edmonton
2007
2008
4/5
5
3/5
4
2006
n/a
0
2007
2008
3/5
5
3/5
5
80 cm / 75 cm
40 cm / 45 cm
70 cm / 50 cm
mice damage 2008
1 specimen
none
none
5
4
4
Bloom Rating: 5 = 100% plants bloomed; 0 = 0% plants bloomed
Overall Quality Rating: 5 = highly recommended; 4 = recommended; 3 = recommended with limitations; 2 = not recommended;
1 = failed due to unfavourable conditions
Winter Survival ratio indicates the number of plants that over wintered successfully/number of original plants
19
Heuchera‘Peach Flambe’
coral bells
Plant Form:
low mound
Foliage:
basal rosettes of rounded, ruffled leaves, emerges orange-red turning fiery orange red
towards the end of the season
racemes of tiny white flowers on tall scapes, blooms June through July, blooms are
insignificant in terms of ornamental value
; protect from hot afternoon sun, well drained soil, average fertility, performs best
in soil rich in organic matter
striking foliage, performed well at Muttart, late spring emergence, poor viability and
growth at the Calgary Zoo and Olds
Bloom Description:
Culture:
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
n/a
0
Incidence of Pests or
Disease
Overall Quality
Rating
Light Conditions:
Full Shade
2007
Olds College
2008
2006
4/5
1/5
3
0
25 cm / 40 cm
n/a
2
2007
Muttart Edmonton
2008
4/5
3/5
0
0
20 cm / 25 cm
2006
n/a
2
2007
5/5
5/5
3
1
40 cm / 40 cm
ants 2007
none
none
2
3
4
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
20
2008
Heucherella ‘Stoplight’
foamy bells
Plant Form:
low mound
Foliage:
lime green to chartreuse trilobed leaves with a ruby centre and veins
Bloom Description:
short racemes of cream coloured flowers, blooms for the month of June, blooms not
significant in terms of ornamental value
; morning sun only or dappled shade, well drained soil, average fertility, performs
best in soil rich in organic matter
Heucherella is a hybrid between Heuchera and Tiarella, outstanding foliage colour and
variegation, great contrast plant, performed well at the Calgary Zoo and Muttart sites
Culture:
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
Overall Quality
Rating
n/a
5
2007
Olds College
2008
5/5
5/5
3
3
45 cm / 35 cm
2006
n/a
4
2007
Muttart Edmonton
2008
0/5
0/5
0
0
25 cm / 35 cm
2006
n/a
2
2007
5/5
5/5
5
5
45 cm / 40 cm
none
none
none
5
2
5
Bloom Rating: 5 = 100% plants bloomed; 0 = 0% plants bloomed
Overall Quality Rating: 5 = highly recommended; 4 = recommended; 3 = recommended with limitations; 2 = not recommended;
1 = failed due to unfavourable conditions
Winter Survival ratio indicates the number of plants that over wintered successfully/number of original plants
21
2008
Iris ‘Clarence’
tall bearded iris
Plant Form:
upright clump
Foliage:
narrow linear medium green leaves
Bloom Description:
pale blue upright petals, ruffled violet blue falls with white beard, blooms mid June to
mid July, fragrant, may rebloom later in the season
; well drained fertile soil, does not tolerate boggy soil
Culture:
huge beautiful and showy blooms, visitor favorite, rebloom in 2007 at Muttart, lost one
plant due to an irrigation break at the Calgary Zoo, poor performance at Olds site may be
related to root competition with neighbouring spruce
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
n/a
0
Average Max.
Height / Spread
Incidence of Pests or
Disease
Overall Quality
Rating
Light Conditions:
Full Shade
Olds College
2007
2008
5/5
1
5/5
4
2006
n/a
0
Muttart Edmonton
2007
2008
7/8
0
6/8
1
2006
n/a
0
2007
2008
8/8
3
7/8
4
70 cm / 60 cm
40 cm / 40 cm
70 cm / 65 cm
none
none
none
5
3
4
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
22
Lathyrus vernus
perennial sweet pea/spring vetch
Plant Form:
irregular mound
Foliage:
light green compound pinnate leaves with acute tips
Bloom Description:
raceme of deep mauve blue sweet pea-like flowers, blooms early May to early June
Culture:
; performs best in well drained humus rich fertile soil, will tolerate a wide range of
soils
received the Royal Horticultural Society’s Award of Garden Merit, non climbing, great
early spring bloom, attractive seed pods, foliage stayed fresh looking all season, minor
hail damage at Olds site in late June, 2008
Comments:
Calgary Zoo
2006
2007
Olds College
2008
Winter Survival
Bloom Rating
Average Max.
Height / Spread
n/a
0
5/5
5/5
3
4
40 cm / 50 cm
Incidence of Pests or
Disease
Overall Quality
Rating
mild slug damage at season’s end 2007
4
2006
n/a
0
2007
Muttart Edmonton
2008
5/5
5/5
0
4
25 cm / 45 cm
2006
n/a
0
2007
4/5
4/5
5
5
35 cm / 45 cm
? caterpillar damage 2008
none
4
4
Bloom Rating: 5 = 100% plants bloomed; 0 = 0% plants bloomed
Overall Quality Rating: 5 = highly recommended; 4 = recommended; 3 = recommended with limitations; 2 = not recommended;
1 = failed due to unfavourable conditions
Winter Survival ratio indicates the number of plants that over wintered successfully/number of original plants
23
2008
Leucanthemum x superbum ‘Crazy Daisy’
shasta daisy
Plant Form:
upright clump
Foliage:
long dark green serrated leaves with rounded tips
Bloom Description:
large semi-double white ray florets with yellow disc centres, blooms mid July to
September, attracts butterflies
; well drained soil, average fertility, must have good winter drainage
Culture:
attractive, large flowers, poor viability and performance at the Calgary Zoo, surviving
plants were very floppy and had few blooms, likely due to wet and heavy soil
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
n/a
0
Incidence of Pests or
Disease
Overall Quality
Rating
Light Conditions:
Full Shade
2007
Olds College
2008
3/5
2/5
5
2
70 cm / 75 cm
2006
n/a
0
2007
Muttart Edmonton
2008
5/5
4/5
5
5
55 cm / 65 cm
2006
n/a
2
2007
5/5
5/5
5
5
90 cm / 75 cm
slugs 2006
minor spittle bug 2008
none
2
4
4
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
24
2008
Ligularia ‘The Rocket’
ligularia/leopard plant
Plant Form:
large mound with flower scapes rising above foliage
Foliage:
large, deeply incised arrow/heart shaped medium green leaves
Bloom Description:
long racemes of small bright yellow star shaped florets, blooms mid July to September
Culture:
Comments:
; moist to wet organic soil
reliable performer, wilts readily during hot spells of the summer, requires shade and
even moisture
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
Overall Quality
Rating
n/a
5
2007
Olds College
2008
5/5
5/5
4
5
165 cm / 125 cm
2006
n/a
4
2007
Muttart Edmonton
2008
5/5
5/5
5
5
100 cm / 75 cm
2006
n/a
5
2007
4/5
4/5
3
5
100 cm / 55 cm
slugs 2007
none
none
5
5
4
Bloom Rating: 5 = 100% plants bloomed; 0 = 0% plants bloomed
Overall Quality Rating: 5 = highly recommended; 4 = recommended; 3 = recommended with limitations; 2 = not recommended;
1 = failed due to unfavourable conditions
Winter Survival ratio indicates the number of plants that over wintered successfully/number of original plants
25
2008
Miscanthus ‘Giganteus’
giant silver grass
Plant Form:
tall erect grass with arching foliage
Foliage:
broad strap-like bluish grey green leaves with a silver stripe down the centre
Bloom Description:
large showy pinkish red panicles, did not bloom during trial period
; average to moist well drained , tolerates poor soil
Culture:
tall and stately, plants in study showed sparse foliage, not reliably hardy
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
n/a
0
Overall Quality
Rating
Light Conditions:
Full Shade
2007
Olds College
2008
5/6
1/6
0
0
180 cm / 135 cm
2006
n/a
0
2007
Muttart Edmonton
2008
4/5
0/5
0
0
140 cm / 150 cm
2006
n/a
0
2007
2/5
0/5
0
5
185 cm / 100 cm
none
none
none
2
2
2
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
26
2008
Miscanthus ‘Purpurascens’
orange flame grass
Plant Form:
upright vase shape with arching tips
Foliage:
green grassy foliage in the summer changing to orange/rust in fall
Bloom Description:
tassel-like reddish panicles fading to silver white
; average to moist well drained soil, average fertility
Culture:
Comments:
selected in Germany in the 1960’s, attractive orange foliage later in the season,
spectacular when back lit with morning or evening sun , lack of vigour at Olds site may
be related to heavier soil, adds great texture to the perennial garden
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
Overall Quality
Rating
n/a
0
2007
Olds College
2008
6/6
6/6
0
0
105 cm / 80 cm
2006
n/a
0
2007
Muttart Edmonton
2008
5/5
5/5
0
0
65 cm / 65 cm
2006
n/a
0
2007
5/5
5/5
0
2
110 cm / 75 cm
none
none
none
4
3
5
Bloom Rating: 5 = 100% plants bloomed; 0 = 0% plants bloomed
Overall Quality Rating: 5 = highly recommended; 4 = recommended; 3 = recommended with limitations; 2 = not recommended;
1 = failed due to unfavourable conditions
Winter Survival ratio indicates the number of plants that over wintered successfully/number of original plants
27
2008
Miscanthus sinensis ‘Huron Sunrise’
maiden grass
Plant Form:
tall vase shape
Foliage:
large grass-like foliage, medium green leaves with cream mid ribs
Bloom Description:
airy brownish rose plumes fading to brown
; well drained soil, average fertility, tolerates wide range of soil conditions
Culture:
developed by Martin Quinn of Canada, graceful and unusual plumes, surviving plants at
the Calgary Zoo and Olds showed poor viability and sparse growth
Comments:
Calgary Zoo
2006
Winter Survival
Bloom Rating
Average Max.
Height / Spread
Incidence of Pests or
Disease
n/a
5
Overall Quality
Rating
Light Conditions:
Full Shade
2007
Olds College
2008
6/6
4/6
0
0
115 cm / 70 cm
2006
n/a
0
2007
Muttart Edmonton
2008
5/5
2/5
0
0
55 cm / 60 cm
2006
n/a
1
2007
5/5
0/5
5
0
100 cm / 60 cm
none
none
none
2
2
2
Part Shade
Full Sun
n/a: not applicable
+ : number of replacement specimens planted if required
Blank Spaces in table indicate a selection not grown that year or that more information was required before assessment could be made.
28
2008