Ooops! They did it again.

 

Clemson News, published by the College of Agriculture, Forestry and Life Sciences; Public Service and Agriculture announced “South Carolina will become only the second state in the United States to ban the nursery sale of Bradford pear trees and any other pear trees grown on the commonly used Pyrus calleryana rootstock.” This does not mean that it will be illegal to own them, but the authorities would be thrilled if you would destroy any in your landscape.

Why? 

“It has all the characteristics of a noxious weed,” said David Coyle, assistant professor of Forest Health and Invasive Species at Clemson.

“Bradford pears were once touted as sterile, but it turns out that if pollen from any other Pyrus species gets into Bradford pear flowers, the trees can make viable seeds. Those seeds are then eaten by birds and other animals and spread across the Southeastern landscape, contributing directly to one of the worst invasive plant species in the region — the Callery pear.”

It’s about time. I’ve never liked them anyway. The angles at which the limbs grow upward make them prone to splitting, and the flowers stink. None of the other Callery varieties promoted for their improvements over the ‘Bradford’ have been any better. Though its usefulness is short-lived, 'Bradford' is a curse that keeps on giving. So, yes, it’s time for them to go. Past time, in fact.

But, wait. There’s something else you should know. The U.S. Department of Agriculture, The New York Times, and even Lady Bird Johnson promoted 'Bradford' pear. It was released for commercial use by the U.S. Department of Agriculture in January 1960 and distributed to nurseries from New York to California. Think about that when you’re driving through the countryside and seeing them dominating the landscape.

The USDA duly noted, “The Bradford will not, under most conditions, fruit when planted—

• More than 200 feet from pear trees of any kind.
• Next to other Bradfords, the common pear (Pyrus communis), or the Hansen pear {P. sp. Hansen).

“The tree will fruit, however, when planted within 200 feet of other selections of the Callery pear tree or such rarely used minor species as the Manchurian pear {P. sp. Manchurian) or the Forostovsky pear.”

Did anyone consider that pollination vectors such as wind and insects can travel farther than 200 feet, and that thousands of homeowners and landscapers would line their driveways and streets with them?

Should we be surprised? This is the government agency that promoted Kudzu as a “wonder plant” for erosion control and even for shade, and Bahia grass for pastures and lawns. Then 'Bradford' was touted. Ooops! They did it again.

Has the USDA benefited agriculture? Sure it has, but it’s difficult for me to remember any particular instance when I see ‘Bradford’ et al, Kudzu vines and Bahia grass infesting the country.

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Something you should know BEFORE you buy your plants.

Will those plants survive the winter where you live?

Nearly every plant catalog and label comes with valuable information for each plant to help gardeners like you enjoy growing success. One of those info bits might read something like this, “Zone: 3 to 8”. But what does it mean for you? You'd better check out the climate map.

Making sense of local climates

Climatologists and horticulturists have long tried to make sense of the earth’s geography and climate to better understand how plants relate to their environments, and how they might perform in them. Such knowledge would help farmers and gardeners enjoy success. So climate zone maps were developed, sort of like road maps to benefit just about anyone who worked with plants. There was a lot riding on it, too, not only for gardeners, but because entire industries relied on the data for their businesses.

They had to gather and study climate data collected over many years. Imagine the many locations throughout the U.S. where weather statistics had to be recorded, then collated. That was a huge undertaking.

A short history of climate map-making

In 1990, the U.S. Department of Agriculture (USDA) published a climate zone map based upon data spanning the years from 1974 to 1986. The American Horticultural Society produced a map in 2003 from info gathered from 1987 to 2002. The Arbor Day Foundation released a map in 2006 from statistics taken from 1990 to 2005.

As you might expect, the climate zone delineations differed, which made matters rather confusing. In some cases, a location on one map would be in a different climate zone than on another. The spans of years differed. The locations of data gathering differed. So did their conclusions. Frankly, there were some areas of the country where climate data wasn’t gathered at all. Perhaps it was because they were inaccessible, or there were just too many places to actually study.

Then, the USDA published another map in 2012 based on a larger sampling of data from 1976 to 2005. It’s called The USDA Plant Hardiness Zone Map, and is the one in use today. It used an algorithm developed by the University of Oregon PRISM Climate Group. The method involved estimating climate conditions, which seemed like a pretty good idea.

How to read the map

The map shows a series of lines winding in and out of various parts of the U.S. Sometimes you’ll see enclosed patches or circles. Some of the spaces are very wide. Other spaces are quite narrow. The spaces between the lines are color-coded. These represent separate climate zones. There are 26 of them. You’ll see 1a and 1b, 2a and 2b, 3a and 3b, and so forth, all the way through 13a and 13b. Each of those zones represents a 5-degree Fahrenheit temperature range, and a corresponding range in Celsius.

Here’s an important point. The map is based upon the average annual minimum temperature. It says nothing about heat, humidity, or any other climate condition. What that means for any particular plant is that it is likely to survive the winter in whatever zone it’s rated for. If the plant is rated for zone 6, it will likely survive a minimum winter temperature of minus 10-degrees F. At any rate, the map only suggests the likelihood of survival; it’s not a guarantee.

The times they are a-changin'

I used to keep a large printed copy of the 1990 USDA map in my garden shop to display to shoppers, with a bright red push pin to show where we were located. If they were from another county or state, we’d find it on the map. “There---it---is---right-----THERE.” Those days are over. Though less nostalgic, the new map is downloadable to your computer, or you can use the interactive map on the USDA website. All you do is type your zip code into the field provided, press “enter" and Voilà!  You have your zone.

I don’t have the map on my wall now, and even if I did, you wouldn’t be able to see it. So, I’ve progressed with the times. I’ve included a link on every description page of my online plant catalog. If you’re considering whether a plant is right for your climate zone, just click the link. You’ll be taken to the USDA site under a separate tab (so you don’t lose your place in my catalog).

See for yourself

Check it out. Go to the plant catalog at GoGardenNow.com, and see the USDA Plant Hardiness Zone Map in action.

While you're there, be sure to sign up for our newsletter so you can be among the first to receive GoGardenNow news and gardening tips.

Unwanted Immigrant - The Spotted Lanternfly

Credit: Pennsylvania Department of Agriculture

"An invasive insect species native to China, India and Vietnam is posing a problem in at least two states" reports Fox News. "The spotted lanternfly is harming crops in Winchester, Virginia", and has been spotted in Pennsylvania. Apparently, the pest was observed in Pennsylvania as early as 2014. 

According to the USDA, "spotted lanternfly feeds on a wide range of fruit, ornamental and woody trees, with tree-of-heaven being one of the preferred hosts. Spotted lanternflies are invasive and can be spread long distances by people who move infested material or items containing egg masses. If allowed to spread in the United States, this pest could seriously impact the country’s grape, orchard, and logging industries."

The USDA advises:

• Inspect your trees and plants for signs of this pest, particularly at dusk and at night when the insects tend to gather in large groups on the trunks or stems of plants.
• Inspect trees (in particular, tree of heaven), bricks, stone, and other smooth surfaces for egg masses.
• If you find an insect that you suspect is the spotted lanternfly, please contact your local Extension office or State Plant Regulatory Official to have the specimen identified properly.
• Locate the Extension specialist near you
• Contact your State Plant Regulatory Official 

If you live in Pennsylvania, an interactive plant pest quarantine map is provided to see if you’re in the spotted lanternfly quarantine.

As noted, spotted lanternfly is particularly attracted to "tree of heaven." Ironically, "tree of heaven" is not heavenly at all. According to the Nature Conservancy, "It is a prolific seed producer and can thrive in even the most unfavorable conditions with little management. Its rapid growth also means that it can crowd out nearby native plant species, and its aggressive root system can cause damage to pavement, sewers and building foundations."

It also attracts spotted lanternfly, which can be a bad thing or good. The bad thing is that it's a host plant for the little creatures. The good thing is that, as a spotted lanternfly magnet, a whole gathering can be eliminated in one place.

I guess those "No matter where you are from, we're glad you're our neighbor" yard signs don't actually apply to all.

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