Horticulturist explains new USDA plant hardiness map

Feb 16, 2012 By Lois Stack

The recently released USDA Plant Zone Hardiness Map, updating the previous 26-year-old zone map, reflects rising mean temperatures throughout the country, including Maine, where gardeners must carefully consider possible temperature dips as they anticipate spring planting.

University of Maine Cooperative Extension professor and ornamental horticulture specialist Lois Berg Stack is available to explain what the new map might mean for Maine gardeners, in addition to suggestions about preparations for early planting.

The hardiness zone map has always been a suggestion for plant selection, not a guarantee, says Stack. Lots of other factors – length of growing season, accumulated heat during growing season, water availability, nutrient availability, soil type, general plant maintenance, etc. – are equally important.

“I usually tell people that the hardiness zone rating is a starting point,” she says. “And, although we do have climate change, and the new reflects some ‘warming’ in some parts of Maine, it is based on one thing: the single coldest each winter, averaged over several years. have to survive each day, one by one. Although our winters may be warmer on average, we still have cold temperatures every winter.”

Stack also says that February is the start of the gardening season – the time to start onion seeds for next winter’s storage, time to take cuttings of geraniums that have overwintered on a windowsill, time to visit a local garden center to for inspiration, or the time to take a gardening course or read a gardening book.

February also is the perfect time to cut tree and shrub branches to bring indoors to force their flowers into color, she adds.

Explore further: Europeans have unknowingly contributed to the spread of invasive plant species in the US

Related Stories

New map for what to plant reflects global warming

Jan 25, 2012

(AP) -- Global warming is hitting not just home, but garden. The color-coded map of planting zones often seen on the back of seed packets is being updated by the government, illustrating a hotter 21st century.

Fight droughty dullness with cool-season euphorbias

Oct 31, 2011

Find the lack of fall colors this year depressing because of the drought? Texas Superstars newest selections, cool-season euphorbias, can brighten up landscapes throughout the winter, said a Texas AgriLife ...

Keep It Growing -- Plant Fall and Winter Vegetables in July

Jul 14, 2008

(PhysOrg.com) -- In mild parts of western Oregon and along most of the coast, it is possible to grow a succession of garden vegetables throughout the year. You can extend the season well into fall in many parts of the Pacific ...

New eco-friendly foliar spray provides natural anti-freeze

Dec 14, 2011

Cold-weather garden enthusiasts have a new reason to celebrate. Researchers at The University of Alabama and Miami University of Ohio have introduced an innovative, all-natural foliar spray that protects plants, both externally ...

Maine weather wreaking havoc on deer

Mar 30, 2008

Deer living in Maine and other portions of New England are likely battling starvation because of the region's tough winter, biologists say.

Recommended for you

Restored streams take 25 years or longer to recover

6 hours ago

New research has found that the number of plant species growing just next to restored streams can take up to 25 years to increase above those channelized during the timber floating era. This is according ...

Why haven't Madagascar's famed lemurs been saved yet?

8 hours ago

Lemurs are cute – there is no denying it. Their big eyes and fluffy faces mean they really are the poster animals of Madagascar, an island known internationally for its unique flora and fauna. But the plight ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.