Oaks of Northern Minnesota

Seven species of oak trees are native to Minnesota, according to the website of the Minnesota DNR. Three of these are found in northern Minnesota; the Bur Oak (Quercus macrocarpa), Northern Red Oak (Quercus rubra), and Northern Pin Oak (Quercus ellipsoidalis).

There are two main groups of oak trees, the white oaks and the red oaks. Leaf shape is the easiest way to distinguish between these two groups of oaks. Leaves of white oaks typically have rounded lobes, while red oak leaves have several pointed tips. The Bur Oak is a white oak and the Northern Red Oak and Pin Oak are red oaks.

Leaves of the northern Minnesota red oaks, the Pin Oak and the more common Northern Red Oak, are shown in the picture gallery below. These trees are difficult to tell apart. Pin Oak leaves typically have deeper indentations between their pointed lobes. I believe the leaves in the two pictures in the upper row are from Pin Oaks while Northern Red Oak leaves are shown in the bottom row.

Leaves of the Bur Oak are shown in the following picture gallery. Bur Oak is the only white oak commonly found in northern Minnesota, the rounded lobes of its leaves are diagnostic of white oaks.

Oaks rely on the wind for pollination, which requires them to produce enormous amounts of pollen. Oak pollen is shed from male flowers called catkins over a period of about four days each spring. The picture below shows catkins hanging from a branch of a Bur Oak.

May 29, 2021

The images below compare a Bur Oak nearly leafless in mid-May and later in mid-June with its full complement of leaves.

Bur Oak, May 15 and June 12, 2021

Hawk’s Nest in our Sweetgum Tree

A pair of hawks have built their nest in the sweetgum tree in our front yard in Louisiana. The nest is too high for us to see any chicks, but there are calls that sound like chicks and the two adult hawks seem to be tending a brood.

Identification of the hawk’s species was difficult because we have only seen the birds fleetingly from a distance. Our first guess was the broad-winged hawk, but by comparing their calls to on-line references, I am now fairly confident that they are red-shouldered hawks.

Our hawk’s call is heard in this video

The call of this hawk compares closely to calls of the red-shouldered hawk that are available at this link.

Red-shouldered hawks are birds of the woodlands, found throughout the southeastern United States and also in California. In the south these hawks do not migrate far, and they commonly use their nests for more than one season.

Red-shouldered hawk near its nest in our sweetgum tree.

Historically red-shouldered hawks have been one of the most common hawks in North America, but deforestation has greatly reduced their numbers. They are now found occasionally in wooded suburban areas. They most commonly nest in tall deciduous trees, like our sweetgum.

One of the hawks flapping as it moved from one branch of the sweetgum to another.

Advocating for Planting Roses

Rose plants in your landscape reward a little effort with terrific value. Over the past month in my yard in SE Louisiana several roses have exploded with blooms. Some of these roses also bloomed in the winter months, but then it was just one flower at a time and the blooms developed over several weeks.

The pictures below feature two quite different kinds of roses from my yard this April. The red roses are “Knockout” roses, which are hardy, disease resistant, and repeat bloomers. All the other pictures show English roses that are fancier, but require a bit more tending.

Antelope Island, by the Great Salt Lake

Antelope Island State Park in Utah is on the shore of the Great Salt Lake. In addition to beautiful scenery, visitors to this park can expect to see bison, mule deer and other wildlife. The pictures below were taken in early April, the haziness of the day added to the impact of the views. From certain vantage points it seemed like an alien world.

Great Salt Lake shoreline seen from hill at Antelope Island State Park

The bison at Antelope Island are not truly native, they were introduced in 1893. The original 12 animals have now multiplied into a herd of 550-700.

A bison wanders alone toward the lake while a mule deer stays in the surrounding brush

Stewart Falls, near Provo Utah

Recently five of us (three people and two dogs) had the good fortune to hike to Stewart Falls on a gorgeous day in early April. The walk to the falls and back was just 3.5 miles, but made a bit more challenging by stretches of not-yet-melted snow. The following photos and videos attempt to capture some of the beautiful scenes along the trail.

This link takes you to a site with a map and description of the area.

Starting Point
View along the way
The upper section of the falls was still mostly frozen
The lower section of the falls, flowing freely
A view from behind the falls

A Good Year for Azaleas

This is a gorgeous time of year in SE Louisiana, and the azaleas are blooming vigorously. By my memory, this azalea display in 2021 is much better than last year’s. To bloom their best, azaleas typically need 4-8 weeks of temperatures below 50 degrees Fahrenheit in the preceding winter. So, I wondered whether a mild winter in 2019-20 might have been responsible for the underwhelming azalea blooms in 2020.

To investigate whether there were insufficient chilly days for azaleas in the winter of 2019-20, I downloaded local temperature data for the last two years (available from NOAA). The data was from a nearby small airport and consisted of daily min and max temperatures. These two values were averaged to estimate an average temperature for each day. In the chart below these average temperatures are plotted from mid-June 2020 to mid-March 2021.

Tallying sub-50 degF days reveals there were 20 in the winter of 2019-20 (slightly less than 3 weeks) and 38 in the winter of 2020-21 (more than 5 weeks). Recalling that 4-8 weeks of chilling are needed for optimum azalea blooming, it does seem that a mild winter may have led to a disappointing show of azaleas in 2020.

Azaleas in 2021

Conifers; Utah’s Wasatch National Forest

A winter trip to Utah offered the opportunity to appreciate conifers in a different part of the country. The photos below show three trees seen along the Mirror Lake Scenic Byway in the Uinta-Wasatch-Cache National Forest, east of Salt Lake City.

Lodgepole Pine

The Rocky Mountain Lodgepole Pine (Pinus contorta subspecies latifolia) is found at middle elevations (4,400-7,800 feet) throughout the northern Rocky Mountains.  This tree is closely related to the Jack Pine that is found in Minnesota. Like the Jack Pine, its needles grow in bundles of two per fascicle.

White Fir

White Fir (Abies concolor) is common in the Rocky Mountains at elevations from 3000 to 10,000 feet. It grows to 130 feet, considerably larger than Minnesotan Balsam Fir which most commonly ranges from 45 -65 feet. The White Fir provides high-quality lumber and is popular as a Christmas tree.

Rocky Mountain Juniper

The Rocky Mountain Juniper (Juniperus scopulorum) is a small tree, typically between 15 and 45 feet. Individual trees can reach great ages, the Jardine Juniper in Northern Utah is estimated at ~1500 years old.

Grandiflora Rose – Queen Elizabeth

Grandiflora roses are crosses between Hybrid Tea and Floribunda roses. They combine desirable characteristics of the two lines. Their well-shaped blooms on long stems are inherited from the Hybrid Teas, while their hardiness and repeat blooming come from the Floribunda side.

The Queen Elizabeth rose was the first Grandiflora rose. It was introduced in 1954 to commemorate the coronation of Queen Elizabeth II in 1953.

The slideshow below follows the development of one bud on our Queen Elizabeth rose this January. This plant has been a hardy bloomer, reliably flowering for over twenty years.