PerennialWhats the difference?
Hardiness Zones are areas in the
United States that share the same average winter temperature: the lower the number the
colder the area. Knowing a plants zone rating helps gardeners determine if it is
hardy enough to survive the winter. The Denver-area is Zone 5. That means a plant labeled
as hardy to Zone 3, 4, or 5 should survive here. Remember, hardiness zones are
rules-of-thumb, not guarantees!
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Annuals are plants that complete their life cycle
in one growing season: from seed, to plant, to flowering, to seed production. The plant
dies at the end of the season. Many annuals are self-sowingthat is, the seeds
they produce start new plants near the same place the following year.
Biennials are plants which grow through one
season, bloom the next season, then die. .Like annuals, many self-sow.
Perennials are plants which grow during the spring
and summer, remain dormant during the winter, then grow again the next season. Some, like
peonies, are very long-lived. Others, like penstemon, may last only a few years. Some may
not begin to bloom until the second or third season after planting.
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Microclimates are areas within a
landscape that differ from the rest in temperature, sun exposure, and moisture. Since
plants respond to these three factors, location makes a difference. Microclimate
may explain, for example, why a Zone 6 plant which "shouldn't" do well in
Denver, thrives in a certain part of your garden, or why a plant your neighbor grows does
not do well in your yard. Identifying the microclimates on your site will help you put the
right plant in the right place.
MICROCLIMATE CONDITIONS THAT MAY EXIST
||Most sunlight. Earliest growth and flowers.
Possible winter-damage to broad-leaf evergreens. Hot, dry conditions near walls.
|Generally good gardening sites. Especially
good for roses and broad-leaf evergreens. Somewhat cooler than south or west. Part-shade
|May be warmer than other exposures due to sun
intensity and radiated heat. Drying winds may be a problem. Good for plants that thrive on
intense sunlight and dryness. Other plants may need more water and mulch.
||Little direct sunlight. Plants start later and
end season sooner. Not as much temperature fluctuation as southern and western.
Shade-tolerant plants do well.
||North-facing provide protection to plants
below. South- or west-facing may be very hot and dry.
|Water, including pools
|Reflected heat from buildings, streets,
||Creates hot, dry conditions.
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