With the passing of this summer’s heat, wind and drought, I have noticed a lot of struggling plants with stem die back, crispy leaves with poor color and overall signs of severe stress that makes me think that those plant’s days are numbered even if the rain returns. Then recently while removing dead plants (casualties of last summer) from the Lincoln NGPC grounds, I noticed two handsome plants that stood out from others nearby. They were growing next to each other and looking really good; one a conifer tree and the other a deciduous shrub. They had been planted as a part of a screening project about eight to ten years ago. Each plant looked visibly healthy with good color; no die back, healthy foliage and the shrub was displaying beautiful fall color and fruit, all of this with no supplemental water during the summer.
This story is even more interesting considering the native ranges of these two plants. The tree Southwestern White Pine is native to desert mountain ranges of the southwest U.S. and the shrub Rusty Blackhaw Viburnum is native to open woodlands of the southeastern states west to the central U.S. What these very different plants have in common and the reason that they survived this past summer is built in drought tolerance.
The conifer tree, Southwestern White Pine (Pinus strobiformis) is a very drought tolerant evergreen found growing natively from Mexico north into the U.S. in the desert mountainous areas of west Texas, New Mexico, Arizona and also southwestern Colorado. It can reach heights to one hundred feet in the wild but would be much smaller under cultivation in Nebraska (30-50 feet). Southwestern White pine tends to be pyramidal in youth with sweeping branches holding 3-6 inch long blue-green soft needles in groups of five, but becomes more irregular and open with age. The bark is smooth and a silver-gray color on young trees becoming darker and furrowed with age. The attractive cones are up to a foot long. I would recommend planting this tree statewide, and especially mid-state westward. Southwestern White Pine can be used in windbreaks, wildlife plantings and as a landscape specimen and should be planted in full sun in an area with good soil drainage.
The other plant of this story is Rusty Blackhaw Viburnum (Viburnum rufidulum) a deciduous shrub found growing from Virginia to Florida and west to eastern Texas, Oklahoma and southeast Kansas. This tough and beautiful shrub is found growing in open, dry to rocky woodlands, thickets and along river banks in well drained soils including sand, loam and clay. Rusty Blackhaw is a stiffly branched multi-stemmed shrub growing 8-15 feet tall with shiny leathery dark green summer leaves that change from green to yellow-orange and burgundy colors in the fall. The stems, buds and leaves have fine reddish-brown hairs covering them and they give the plant its rusty appearance. The fruit, a drupe, is raisin sized and changes with the seasons from green to glaucous blue and finally a dark purple in late winter; it is eaten by birds and small mammals. Rusty Blackhaw Viburnum will grow in part to full sun in well drained soils and is a beautiful shrub for landscaping, screening and woodland gardens as well as wildlife plantings. It could be tried statewide, but may be more suited from the central part of the state eastward.
So ends the tale of two tough plants from different regions of the country that ended up together by chance and survived one of the toughest summers on record!