Question
Dear Experts,

I bought the above Genista to add to my garden this year.  My neighbor told me he had recently talked to someone who has a Genesta plant and has for 20 years been trying to get rid of it.  I don't know what species his is.

Am I going to have problems with my Genista popping up all over the place?  Perhaps all species of Genista don't behave that way.  I would also like to know if Genista would do well in a large patio pot.

Thanks for your time and information.

Answer
For some reason, people this summer seem to be losing a lot of sleep over Brooms.  This is the Annuals forum at Allexperts.  For the record, Brooms are shrubs, they are perennials, they are NOT Annuals, unless you kill them.  In your case, you have not even planted it yet, so there's no excuse for me posting this here, but I have permission now, and we will proceed.

Will this plant give you problems?

It depends. One man's Genista is another man's poison.

One of the most invasive plants in the country is a weed called Annual Bluegrass (Poa annua).  But in many regions, it抯 called the Lawn.  Even some golf courses grow it -- one of the most famous, Oakmont Country Club in Pennsylvania, cultivates it on fairways, tees and greens.

The USDA, however, calls the same plant a 'harmful organism, crop pest and potential seed contaminant'.  Millions of dollars are poured into research in search of something to kill it, because this is one of the most resilient members of Kindom Plantae.

Invasive species have endured millions of years braving some very mean elements. Many invasives need specific climactic and soil conditions to survive. But when they do, watch out.

That's how it is with invasive plants.  Those we love to hate most are relegated to their place on the USDA's official federal Noxious Weeds list, the botanical version of America's Most Wanted:

www.plants.usda.gov/java/noxious?rptType=Federal

Individual states also draw up local lists.  In many regions, it is illegal to let noxious weeds grow.  You can be fined and, probably worse, your house be filmed and appear on the 5 o'clock news.

Relax.  Genista is only a problem if you live in Northern California or Oregon:

www.plants.usda.gov/java/noxComposite

Since you didn't state your location, that means you have only a 2 in 50 chance of asking for trouble when you grow Genista, about 4 percent.  Less, if you're growing this in a U.S. protectorate or another country.  Plus, it's only French Broom, Genista monspessulana (aka Cytisus monspessulanus and Teline monspessulana), that poses a threat to the quiet enjoyment of your landscape. Not G. spechiana.
Not sure?  Here's what it looks like:
www.calphotos.berkeley.edu/cgi-bin/img_query

As you probably noticed, your Genista has 3 official names.  Genista is a complicated, confusing genus.  In 2002, British scientists analyzed the DNA of Canary Island and Madeira Brooms, and still could not agree on the differences between their molecular sequences.  Some Genista, such as G. benehoavensis, are actually quite rare.  The 2002 study was written up in a report, 'Different fates of island brooms: Contrasting evolution in Adenocarpus, Genista, and Teline (Genisteae, Fabaceae) in the Canary Islands and Madeira', published in the American Journal of Botany in 2002:

www.amjbot.org/cgi/content/full/89/5/854

G. spechiana? As I pointed out to a previous gardener, who was struggling with this very plant in a landscape in Texas, this broom is not as tough as some the Brooms species. Native to the Canary Islands, it is not adapted to weather that reaches stretches of 90 degrees.  In the Canary Islands, the temps don't even hit the 80's.

Now, how different is G. spechiana from the illegal, invasive Genista?

Next time you toss a tomato in your salad, next time you are whipping up a pot of mashed potatoes, consider this:  If that was the fruit of Solanum dulcamara or S. nigrum, instead of Solanum lycopersicum (the tomato) or Solanum tuberosum (potato), you would be dead.  Plus, tomatoes and potatoes don't look, smell or grow the same.  G. spechiana? Fear not.

Peace,

THE LONG ISLAND GARDENER