Kathy Zuzek

Transcription

1 Kathy Zuzek Started in early 1990 s by Dr. George of Texas A&M Goal: to provide research-based recommendations on environmental stewardship practices in horticultural landscapes Key components of program: 1) identifying and teaching landscape practices focused on: nutrient management with no or minimal inorganic fertilizer applications improving overall soil health with compost & organic mulch water conservation minimizing pesticide use Key components of program: 2) identifying plant cultivars & species that perform well over multiple years & on a regional basis when: compost and organic mulch are used as nutrient sources inorganic fertilizer and pesticide use are eliminated supplemental irrigation is minimized Multiple regional test sites Hydrangea Trial Plot Locations Replicated & randomized trials 4 blocks/trial site 1 plant/cultivar in each block 1

2 Eliminate native vegetation Plowing/tilling Incorporate 3 compost Plant 3 organic mulch Year 1: Plants establish, regular irrigation, no evaluation Years 2-4: Evaluation years No fungicides or insecticides Herbicides only to control invasive weeds No fertilizers No irrigation unless wilt starts to occur Maintain 3 layer of organic mulch Tolerance to Abiotic Stresses: Cold hardiness Heat tolerance Drought tolerance Nutrient deficiencies Disease & insect tolerances Plant size & habit Cercospora Drought Bacterial leaf spot Iron chlorosis/high soil ph Foliar quality Size, color & density Impact of stresses & pests Flower quality Size & color Floral density Repeat bloom or length of flowering season Plants that perform well across all sites are designated as Earth-Kind and publicized to gardeners & hort industry through websites, publications, presentations 2

3 7 Smooth Hydrangea (H. arborescens) cultivars: 1. *Annabelle 2. Bella Anna 3. Bounty 4. Hayes Starburst 5. Incrediball 6. Invincibelle Spirit 7. White Dome *nursery standard 3-5 suckering plant with large showy starting in June Green to white to brown mophead flowers 2-8 toothed leaves Zone 3 (-40 o F) Annabelle C. Bryson, ARS, bugwood.org Loose open 3-5 plant in the wild 3 Bigleaf Hydrangea (H. macrophylla) cultivars: 1. Blushing Bride 2. Endless Summer 3. Twist-n-Shout 3-6 plant with large showy flower heads starting in July Pink, blue, purple lacecap or mophead flowers 4-8 almost succulent leaves Zone 6 (-10 o F) Native to Japan 3

4 14 Panicle Hydrangea (H. paniculata) cultivars: 1. Compact 8. Pinky Winky 2. Great Star 9. Quick Fire 3. Limelight 10. *Tardiva 4. Little Lamb 11. Tickled Pink 5. Little Lime 12. Unique 6. PeeGee 13. Vanilla Strawberry 7. Pink Diamond 14. White Diamonds *nursery standard 3-20 plants with conical to rounded from July through fall Flower heads: sterile bracted flowers to lacecap Flowers start white or ivory and age to pink Zone 3 hardiness (-40 o F) Eastern and southern China, Japan, Sakhalin Panicle Hydrangeas formerly small trees in the landscape with a height of 20 H. paniculata Little Lime H. paniculata White Diamond 4

5 Smooth hydrangea: Invincibelle Spirit Limelight First Editions Vanilla Strawberry Little information on their performance in the Upper Midwest And no information is available on their performance under low input conditions Earth-Kind Hydrangea Trials in the Upper Midwest MN Landscape Arboretum, Chaska, MN: Cottonwood Park, Dilworth, MN: North Central Research & Outreach Center, Grand Rapids, MN: Iowa State University Horticulture Research Station, Ames, Iowa: Boerner Botanic Garden, Hales Corner, WI: September 2010 September gallons of irrigation/ plant from 2012 to

6 August 2011 May gallons of irrigation/ plant from 2011 to 2014 July 2013 Watered twice from 2013 to 2015 August 2014 The Trends Big leaf hydrangeas are poor performers under low input conditions & will not be Earth-Kind plants No major insect problems: Visiting insects caused no or little damage to hydrangea Goldenrod soldier beetles feed on hydrangea pollen Red necked flea beetle, Purdue Extension Red necked flea beetle damage Bacterial leaf spot (Xanthomonas) on smooth hydrangeas may eliminate smooth leaf hydrangeas from Earth-Kind designation Strong differences in stem strength & resulting plant habit will impact E-K designation Pinky Winky Compact 6

7 Strong differences in iron chlorosis on high ph soils Chlorosis common on panicle hydrangea during wet spring of 12 Chlorosis disappeared as soils dried for most cultivars Strong differences in drought tolerance Little Lamb Strong differences in floral quality Little Lime Great Star Strong differences in floral quality Little Lime Great Star 4-5 suckering shrub 4-10 white flowerheads 7

8 4-5 suckering shrub 4-10 flower heads Stiffer stems than Annabelle? flower heads Denser flower head than Annabelle? 4-5 Annabelle Bounty Incrediball Double-flowered w/ star-like flowers that change from green to white Narrow leaflets w/ white fuzzy bottom 3-4 Pink flowers smaller than white cultivars (4-6 ) flat-topped lacecap clusters change from ivory to green 8

9 Great Star 6-7 Limelight 6-10 PeeGee 8-10 PeeGee Compact 6 Pink Diamond 6-8 Pinky Winky 6-8 Unique 6-10 Vanilla Strawberry upright arching plant Large 2-4 flowers (sterile bracts) 6-10 plant Green and cream flowers age to pink, burgundy, and green sterile change from white to pink and bronze 6 small version of PeeGee with smaller leaves and smaller flowers 9

10 6-8 plant 12 creamcolored lacecap age to rosy pink 6-8 plants Conical 14 with double (7 petals vs. 4) flowers Stiff upright stems 6-10 plant Large lacecap 6-7 upright and then cascading plant habit White flowers turn pink and red to give multi-colored Little Lamb 4-6 Little Lime 3-5 Tickled Pink 4-5 White Diamond plant Conical flower heads start white and age to dusty pink Stems can droop under weight of Little Lime 10

11 3-5 Green flowers age to pink and green Fall 4-5 plant Frilly flower heads start white and turn pink Summer 4 compact plant White flowers turn ivory and pink H. paniculata Quick Fire 6-8 plant White lacecap flowers open a month earlier than other panicle hydrangeas and then turn rosy pink 11

12 6-8 rounded shrub 6 lacecap start white and turn pink Blooms in late August & September Questions? Kathy Zuzek kathyzuzek@gmail.com 12