Planting began in 1994 on the grounds of the Sedgwick County Extension Education Center at 21st and Ridge in Northwest Wichita. Our grounds are enthusiastically planted and maintained by our Extension Master Gardeners. Included in the arboretum is a tree collection, raised bed demonstration garden of vegetables and flowers, container gardens, rose gardens, nature trail and ornamental grasses. All plants are labeled for your enjoyment and learning.
Heat and Drought Tolerant Trees
The summers of 2006, 2010 and 2011 brought summer high temperatures of 108-111°F. While some trees tolerated this, others died. Most all of our trees are on a drip irrigation system that gives supplemental watering as needed (no more than once per week) when the buffalograss turf goes dormant due to drought stress.
Our best trees in heat and drought conditions:
Bur, English, Shingle, Sawtooth, Shumard and
‘Legacy’ Sugar Maple
Chitalpa, Catalpa and Desert Willow
We were very impressed that the Chitalpa and Desert Willow continued to bloom through temperatures as high as 111°F.
Trees that We Lost in the Heat
Our most unexpected loss was our Green Giant Arborvitae. This had been growing rapidly for several years and scorched in 2011 at 108°F and died in ’12 right after it hit 111°F. This was common with the Green Giants in the region. Our Black Hills Spruce had dieback at the base and fared better than many spruce in the region.
We are looking at a variety of evergreens to provide winter color after the devastation of our region’s pines from Pine Wilt nematode. Evergreens that are doing well for us are the improved Eastern Red Cedars – ‘Taylor’ and ‘Canaert’; ‘Keteleeri’, ‘Robusta’ and ‘Blue Point’ Chinese Juniper, Bracken’s Brown Magnolia, Blue Atlas Cedar and Berkman’s Golden Arborvitae.
As we look to adding more evergreen color and wind protection we need to look at not what is just popular now, but what has been planted generations ago and is holding up well in these higher temperatures. The Oriental Arborvitaes have held up well and we are adding more to our arboretum in the spring of 2012 including the old varieties ‘Blue Cone’ and ‘Goldspire’ Oriental Arborvitae. We are also adding Incense Cedar, ‘Kashmir’ Deodar Cedar, and additional ‘Canaert’, ‘Taylor’, ’Robusta’ and ‘Keteleeri’ Juniper,
The first three years of establishment is the most critical time for watering trees. Trees grow best if the rootball and surrounding area remains moist but not soggy. During the first year water weekly to saturate the rootball and surrounding area to a depth of 10-12”. (Our Extension Master Gardeners put Gator bags around newly planted trees and fill them with 14 gallons of water each week as well as fill the water ring with water.) A long screwdriver or piece of rebar should easily go into the soil to the full moistened depth. Water again each week if adequate rainfall is not occurring. During the next two years, soak the rootball and surrounding area every two weeks during drought periods. Continuously saturated wet soils can also be deadly to trees. Let the soil dry out between waterings.
Provide supplemental water to established trees every two weeks during drought periods by soaking the entire root zone (this often goes out to twice the branch spread) to a depth of 10-12”. Water slowly by setting a sprinkler in the root zone or set out a soaker hose or a hose with water trickling out the size of a pencil. Let it soak for several hours, or until it has wet the soil to a depth of 10-12”.
Woodchip mulches around young trees has the multiple benefits of holding soil moisture, reducing soil temperature and reducing weed growth.