QUESTION: “We have about 5, very beautiful, English oaks where I work. They look like they're related to the White Oaks, and appear to be doing very well here in Philly...why aren't English Oaks more numerous?” – Scott
ANSWER: English oaks are beautiful trees that, despite their name, are not strictly English as they are also native to much of Europe and also northern Africa and western Asia.
The foliage of an English oak is similar to that of the more familiar White oak but lacks the eye-catching reddish leaf color in fall. You can sometimes spot English oaks in urban landscapes, reaching a height of around 50 feet with a 50 foot spread.
Botanists have been using the English oak as genetic stock to generate hybrids with other members of the White Oak group as they can be very useful landscape shade trees.
Although it is not an American native, English oak adapts to the sometimes challenging conditions of the eastern and midwestern United States. It is at its best in zones 5 and 6 and doesn’t thrive in the hot dry summers of the South. It seems to do okay in moderately dry, poor quality soil, but prefers moist, well-drained, moderately rich soils of variable pH.
Problems? The main potential problem is powdery mildew, something it shares with its cousin White Swamp oak. Powdery mildew can form on its foliage around mid-summer, but is considered a ‘cosmetic’ disease that does not adversely affect the overall health of the tree.
I believe that English oaks are not too numerous due to the simple law of supply and demand. Nurseries grow and sell what people are buying in the greatest quantities. Low demand means fewer English oaks are being grown at the nursery level.
There are a number of hardy and attractive oaks that are fast-growing and fairly easy to care for. I’ll devote a column quite soon to some of these varieties such as Water Oak, Sawtooth Oak, Cherrybark Oak and the ever-popular Trailing Periwinkle need? Is it easy maintenance? If planted on a slope, would I need to plant them high and let them trail down or low and high and let them fill in? I am in Huntsville, AL. How will they do in whatever zone that might be?” – Alex Haynes
ANSWER: The Huntsville, AL area borders zones 7 and 8. Vinca will grow in that region and is recommended for USDA zones 3 through 8. You’ll be pleased to know that, as with most groundcovers, Vinca minor (Trailing Periwinkle) requires minimal maintenance.
After fall planting, average watering will run every 3 to 5 days for the first 6 or so weeks depending on local rainfall, soil type and the planting location. Since you are planting on a hillside or slope, it will vary even more. You will need to check the soil and adjust the water schedule accordingly.
For a slope, I recommend setting up a sprinkler attachment to a hose for a soft spray to moisten the soil. Otherwise, most quick waterings and rainfall typically runs off without soaking into the soil.
Until the plants securely root in, you may need to place a light layer of straw over the area during periods of heavy rainfall to prevent the plants from being washed downhill. Vinca grows and roots wherever the new growth touches the soil. Spacing can vary from 6 inches to 18 inches apart over the entire area. The closer the plants are spaced, the quicker the area will fill in.
Vinca minor is an excellent evergreen ground cover for full sun, shaded and semi-shaded areas. It has dark green oval-shaped foliage and conspicuous blue flowers in early spring.
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