Plant Profile: Southwest White Pine

When one thinks of classic and elegant conifers, Eastern white pine often comes to mind.  Unfortunately in the Great Plains, summer heat, wind and drought restrict growing Eastern white pine to only well protected sites.  We have a stand of Eastern white pines strategically planted with protection from these adverse conditions.  Even these few original Eastern white pines planted in the early 1980’s are slowly expiring because of environmental challenges. 

Fortunately, there is an alternative.  The Southwest white pine, Pinus strobiformis, is a tough, drought- and heat-tolerant conifer. Its native range extends from Texas to Arizona and south to Mexico.  They inhabit dry, rocky slopes in mountainous areas. 

Southwest white pine planted in 2000

Habit

Somewhat shorter and broader than its eastern cousin, the Southwest white pine reaches 30-60 feet in height at maturity, with a broad, rounded crown.  Needles are five per bundle (fascicle), 1.5 to 3.5 inches in length with a dark green to blue-green color.  The top and bottom of the needles have somewhat distinct white stomatal lines.  Though not as long and soft as the needles of the Eastern white pine, the needles are very soft textured and pliant.  The long cylindrical cones mature in two years and produce a brown oval seed that is edible.

This image has an empty alt attribute; its file name is IMG_2207-768x1024.jpg

Culture 

Adaptable to our high pH soils, Southwest white pine prefers well-drained soil in full sun.  It is a moderate to fast grower. Young specimens in the Arboretum have grown 10-12 inches per year since they were planted in the mid-1990s.

Also consider a Southwest white pine as an alternative to Austrian pine, which has suffered from Sphaeropsis tip blight in the last decade.  It can be used as a large specimen or in a screen or windbreak planting. Its hardiness, drought resistance, and fast growth are definite attributes to consider in our challenging climate. 

Alternatives

Other evergreen and conifers we use here at the Arboretum: Arizona Cypress, ‘Taylor Juniper’, ‘Canaertii’ Juniper, Black Hills Spruce, Pinyon Pine and Vanderwolf’s Pyramid Limber Pine.  There are no guarantees on any of these.  They may develop blights, or other diseases in time.  Certainly they are all attractive to bag worms. 

The bottom line is that growing evergreens in Kansas will always be a challenge.  These are the best options for landscapers. Take a look at our 2020 Native Plant Guide for Spring FloraKansas Native Plant Festival for other landscape options.

Arizona Cypress

The Best Trees for Fall Color

‘The best time to plant a tree was 20 years ago. The next best time is now.’

– Chinese Proverb

 

For many reasons, fall is my favorite time of the year.  I love the cooler weather and changing landscapes.  This signals the end of another growing season, but there are still a few highlights to come. The beauty of the fall wildflowers like asters and goldenrods makes them stand out in a sea of grass.  The native grasses are at their peak with attractive seed heads and brilliant fall color.  It is also a time when trees begin to change, developing shades of red, orange, yellow, and tan.  I know winter is coming, but the crescendo of our gardens is fun to watch.

Native Blackhaw Viburnum (Viburnum prunifolium)

How do trees develop fall color?

Fall color in trees is a result of a complex process of removing the green pigment, chlorophyll, from the leaves, which allows the other pigments to be seen.  For instance, carotene and xanthophyll (carotenoids) are yellow pigments that are produced all year long with chlorophyll.  With the shorter days and cooler fall temperatures, chlorophyll production is slowed and the green color slowly disappears revealing the yellow pigments that have been there all year long.  Green ash and ginkgo are good examples of trees with nice yellow fall color.

Other trees produce red and purple pigments called anthocyanins, which tend to cover the yellow pigments present in leaves during the fall.  As the fall season progresses, the increased sugar content in these leaves works to intensify these reddish-purple leaves.  American ash, shingle oak and shumard oak are nice trees with red fall color.

In trees with a combination of carotenoid and anthocyanin pigments, an orange fall color develops.  Sugar maples, smoke trees, and sweet gum trees are wonderful examples with orange fall colors.

Some of our trees have no vibrant fall color, but rather the leaves turn to tans and browns. This is caused by tannins in the leaves, which accumulate as the chlorophyll is removed from the leaves.

Fall color can be a little different every year.  Plant genetics, and environmental conditions make subtle changes from year to year fun to watch.  Each year, there is a unique beauty in the landscape that should be savored, enjoyed and not taken for granted.

White oak

My Favorite Trees for Fall Color

Shumard Red Oak (Quercus shumardii)

This oak tree will reach a height of 40-60 ft. with a nice rounded-pyramidal habit.  It is a stately tree that produces a wonderful range of colors from deep red and maroon to dark oranges.  Fall color can be quite variable from year to year depending on environmental conditions.  Other oaks worth trying: shingle oak, white oak and black oak.

Sugar Maple (Acer saccharum)

Sugar Maples and many other maples are the quintessential tree for fall color. In Kansas, sugar maples are relatively slow growing but worth the wait as a mature tree can put on quite a fall display.  They reach an ultimate height of 40-50 feet tall and equal spread.  The bright red, orange and yellow leaves appear in October and last for many weeks.  Try the cultivars, ‘John Pair’, ‘Autumn Splendor’, ‘Table Rock’, ‘Flashfire’, ‘Oregon Trail’ or ‘Legacy’ for the most consistent fall color each year.

Table Rock Sugar Maple

Bald Cypress

This is not usually recognized as a tree with exceptional fall color, but when the fine leaves turn reddish-brown in the fall, it is striking.  We have planted Our specimens near the pond where the “knees” can develop. The pyramidal habit reaching 50-60 feet tall make it a majestic tree for certain situations. It is certainly worth a try.

Bald Cypress fall color

Others worth noting:

  • Viburnum rufidulum
  • Viburnum prunifolium
  • Cotinus ‘Grace’
  • Betula tremuloides ‘Prairie Gold’
  • Sassafras
  • Ginkgo ‘Autumn Gold’
  • Carya cordiformis
  • persimmon

We are already seeing signs of fall here at the Arboretum.  Fall color starts in September and ends in November with peak coloration sometime in October.  Cool night temperatures above freezing, calm winds, and sunny days will make the colors more intense.  So, even though it’s not New England, let’s enjoy the beauty of fall.

Sugar Maple






Trees For the Kansas Home

At last year’s fall plant sale I convinced my father to plant some oak trees around his house where older shade trees are nearing the end of their lives. I told him to think ahead ten years: when the sweetgum (Liquidambar styraciflua) in the front yard finally dies, won’t he wish that he had a head start on growing the next shade tree nearby? And wouldn’t it be nice to start a row of trees near his workshop to block the hot west sun? Of course! He ended up choosing a few Shumard oaks (Quercus shumardii) which have done well for him and are off to a great start.

These trees were an investment in the future of his property ownership – well placed trees can save you money on heating and cooling your home and offer protection to your roof and siding from the sun’s damaging rays. Are there parts of your yard that need a shade tree? Or perhaps you have a tree that will need replacing in the near future?

Do your research and find the perfect tree for your needs, practical and aesthetic. Following are some of my favorites from the upcoming sale, but a full list is available here.

Fruiters

If you want to add a fruiting tree to your landscape, consider a Kansas native. PawPaw (Asimina triloba) and Persimmons (Diospyros virginiana) are both delicious and underused native fruits. Both are small to medium sized trees when mature (20 to 40 feet tall) and grow well in moist to medium-dry environments.

Persimmon (left) and PawPaw (right) both produce delicious fruit.

Persimmon (left) and PawPaw (right) both produce delicious fruit.

Understory

Sassafras albidium is the host plant for the spicebush swallowtail (Papilio troilus)

Sassafras albidium is the host plant for the
spicebush swallowtail (Papilio troilus)

If you already have some large shade trees and want to add canopy layers, consider an under story tree that thrives in the dappled sunlight and protection of larger trees nearby.  Sassafras trees (Sassafras albidium) have unique foliage, showy spring flowers and all parts of the plant have a pleasant smell. Eastern Wahoo (Euonymous atropurpureus) is known for it’s intense fall color and often grows in a shrubby form.

Flowering

There are lots of showy flowering trees to choose from, but we carry a few particularly unique options. Hop hornbeam (Ostrya virginiana) has cream colored shrimp shaped flowers, seen below. Yellowwood (Cladrastis kentukea) trees have pendulous white blooms and bright golden fall color.

Blooms of hop hornbeam and yellowwood trees.

Blooms of hop hornbeam and yellowwood trees.

Shade

Big sturdy shade trees are a good choice for a homeowner looking to reduce their electricity bills and protect their home from the elements. Black oak (Quercus velutina) and American Chestnut (Castenea dentata) both grow upwards of 60 feet tall and both produce nuts that provide winter food for wildlife.

Planting a tree is a satisfying task — it is an investment in the years to come, the hope of growth and newness. A mature tree can even raise the market value of your home! Tree coupons for the fall plant sale (September  9 – 11) will be available soon on our website. Hope to see you at our upcoming sale, carting away a tree of your own.

Photos from wikimedia comons, attributed to: Asit K. Ghosh Thaumaturgist (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Hophornbeam by Eric Hunt (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
Cladrastus bloom Elektryczne jabłko (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 4.0-3.0-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/4.0-3.0-2.5-2.0-1.0)], via Wikimedia Commons