Monday, July 21, 2014

Summer Blues (and Yellows)

Justin Evertson
      A simple but very effective color combination for the flower garden is blue with yellow. Mother Nature must have understood this from the start as she dispenses both colors in great quantities. In fact, it is relatively easy to keep the color combination going throughout the growing season as different plant species succeed each other in flower prominence. From spring through fall, here are just a few of the great combinations possible:
 ·         Catmint (Nepeta spp.) and Cushion spurge (Euphorbia polychroma): These two plants grow from 10” to 18” tall and are most striking in early to mid-spring.
·         May Night Salvia (Salvia nemorosa) and Moonshine Yarrow (Achillea x ‘Moonshine’): Both plants are extremely reliable, easy to grow, reach about 18” tall and are at their peak in late May to early June.
·         Blue False Indigo (Baptisia australis) and False Sunflower (Heliopsis helianthoides): These two prairie natives grow from 24” to 36” tall and are going strong in late spring and early summer.  Give each plenty of room to grow.
·         Russian Sage (Perovskia atriplicifolia) and Goldsturm Rudbeckia (Rudbeckia fulgida ‘Goldsturm’).  The soft spray-like blue of Russian sage (36” to 48” tall) makes a great backdrop to the summer-long blooms of Rudbeckia (18” to 24” tall). 
From top: catmint; goldenrod; pitcher sage
·         Sunny Border Blue Veronica (Veronica x ‘Sunny Border Blue’) and Fernleaf Coreopsis (Coreopsis verticillata).  Both plants stay under 24” tall and are typically mid to late summer bloomers.
·         Pitcher sage (Salvia azurea) and Goldenrod (Solidago spp.).  Mainstays of the late summer and fall landscape, these native plants can both grow 48” tall, depending on the type selected.  However, both can be cut back frequently during the growing season to keep low and to delay blooming.

Wednesday, July 2, 2014

Rain Gardens

Chadron State College rain garden, planted June 28, 2014
Christina Hoyt

        Water conservation can be as simple as directing downspouts to planted areas, placing small areas of grasses or other deep-rooted plants on slopes or areas off downspouts, decreasing paved areas, using permeable pavers and installing rain barrels. A growing awareness of the pollutants in rainwater, however, has led to the use of rain gardens—depressions planted with native or adapted plants that help absorb excess water and filter out excess nutrients before entering the groundwater system. When placed to receive runoff from roofs, downspouts and paved areas, they can capture and filter as much as 90 percent of common pollutants.

        Plants for these areas need to tolerate extremes since there will be periods of standing water when the soil is saturated and also very dry periods. They are meant to drain within 24-48 hours, a rate that will depend on the amount of runoff the area receives, quality of the soil, plant absorption and the depth of the depression. Recommended depth is about 8” since deeper areas are less likely to drain well, difficult to plant effectively and soil and mulch are likely to erode. Gravel or rocks can be placed where water enters and exits to help slow the water flow, spread it out and prevent erosion.

Lincoln Fireworks rain garden, planted in 2009.
        Some of the plants recommended for rain garden areas in full sun are deep-rooted native and ornamental grasses, black-eyed Susan, goldenrod, iris, butterfly milkweed and gayfeather.

        They can also be planted in part shade with plants like: astilbe, lady’s mantle, iris, Korean reedgrass, sedges, aster, coneflower, turtlehead, Joe Pye-plant, germander, hibiscus, etc.

        Fast facts (more at and 

  • Stormwater runoff is the primary water quality problem in America
  • In cities, about 50 percent of rain water goes into storm sewers
  • Runoff from a 1” rain may exceed 5,000 gallons—even from a 1,500 square foot house on a small lot
  • More than 50 percent of outdoor water usage goes into watering lawns and gardens
  • On a dry summer day in Lincoln, lawns alone may absorb more than 50 million gallons of water per day from the Platte River

        There are a wide range of regional resources on water conservation and rain gardens at and (keyword: rain gardens). Nebraska Statewide Arboretum has a “Waterwise Landscapes” publication and there is a series of stormwater management NebGuidesfrom the University of Nebraska: Rain Garden Design for Homeowners, Installing Rain Gardens in Your Yard and  Plant Selection for Rain Gardens in Nebraska.

Monday, June 30, 2014

A Tree Race--the Acorn & the Potted Tree (Grimm’s “The Tortoise & the Hare” revisited)

Justin Evertson

We’ve been monitoring a small oak-growing study in Waverly the last few years designed to evaluate nursery growing methods of bur oaks.  Bur oaks were planted from three different growing methods: traditional smooth container, fabric grow bags and direct seeding of acorns collected from oaks growing on the UNL campus. The acorns were planted in fall 2011. Nursery trees planted Fall 2012. Care has been minimal, but the trees were watered during exceedingly dry summer of 2012 and again in 2013. Observations so far:

Plastic Container Trees: Started about 1.5” caliper and 10’ tall. They were all pot-bound, with severe root circling in the container. The roots were not cut or squared at planting time. Significant dieback has occurred on all three plants and the root systems are not yet well-anchored. One is completely dead, the other two are re-sprouting from low on the trunk and would likely not be acceptable to the typical tree buyer.

Grow Bag Trees: Started about 1” caliper and 7’ tall. There was minimal root-circling at planting time. The roots were not cut or pulled out at planting time. There was some dieback from the 2012 drought though not nearly as bad as the plastic container trees. All three root systems appear to be well-anchored now.  All trees are putting out good growth this spring and are finally starting to be taller than when they were planted.

Acorn Seeding: There are six trees total (after thinning six batches of seedlings in late 2012). All have grown quite well. Care included rabbit fencing the first two years and occasional watering during the 2012 drought. Four of the trees are already over 5’ tall and two are over 6’ tall (averaging over 3’/year the last two years). The trees are well branched with strong vertical growth.

Conclusion: Plant the acorns if you can! After this year, it is almost guaranteed that the acorn grown trees will all be taller and more resilient (better established roots) than the nursery grown trees. However, the grow-bag trees are clearly superior to the plastic-container grown trees in this study. Considering that they had to survive the terrible heat and drought of 2012, they have done fairly well and would probably be acceptable to the typical tree buyer/planter.

So far, this study confirms the importance of a good root system for establishing young trees. At the end of the 5th year of growth, most trees will be dug up and roots will be closely examined.
PHOTOS from top: grow-bag roots; plastic container roots; planting site.