|Zone 6 has a
medium-length growing season, with a frost-free period that lasts
from mid May til late September.
U.S. cities within this zone include Boston, Buffalo, New
York; Chicago; Columbus, Ohio; Kansas City, Missouri; and Pittsburgh,
Pennsylvania. The average lowest winter temperature is
between -10 and 0 degrees Fahrenheit. You can grow a wide variety of
plants in this hardiness zone, and I do.
There are thousands of plants
that you can grow in your garden, but if you want to grow varieties
that are proven winter hardy, or those that can take high
temperatures and other extremes, choose perennials appropriate for
your state and region. You can have your cake and eat it, too, if
you treat non-hardy plants as annuals, and either re-plant in the
spring, or try to winter them over as houseplants or dormant stock
indoors. I've had great success with hanging succulents, herbs,
bamboos and dwarf fruit trees by wintering non-hardy varieties
Remember that lots of plant
families contain plants for cooler or hotter regions. For instance,
I grow Giant Hibiscus in Zone 6. There are many hardy varieties for
my region. There are also "tropical" Hibiscus, which will
die at the first frost in the northern states. I made that expensive
mistake only once, and I pay more attention when buying from online
nurseries and plant sellers. Not all are labeled or specified as
hardy, and not all listings give you the hardiness zone information.
Most garden centers in big home centers sell plants that are labeled
by the growers, and for the most part, the employees are not
horticulturally savvy. Mislabeling, missing labels, and bad
information is commonplace.
If unsure, check the extension services
in your area for the plants that do best in your climate, then check
the USDA plant hardiness zone map.
It's always best to get your
special and valuable landscape plants from a grower or reputable
plant nursery. Do not make the assumption that if a plant is being
sold in your area, it will thrive and survive. You will also want to
check for potential invasiveness. I've seen plenty of invasive
plants being sold without that important information. I do not want
invasive plants to become a nuisance or plant killers in my gardens.
I once lost a battle, and many perennials, with invasive Lantana.
Very pretty, but impossible for me to get rid of. Mints are also
notorious invaders in that category. Wisteria is another cloaked in
accolades and secrecy - I grow 2 tree wisterias that are
non-invasive, and I trellis them, prune them into shapes I want, and
grow them in big pots. I've seen the structural and tree damage
Wisteria vines do in the south, and many places now have it on their
lists of invasive species. There are non-invasive species of just
about any invasive plant, so don't give up on a plant, just look
is an official list of Pennsylvania's invasive plants. It's
a comprehensive list of damaging and invasive plants in the state,
complete with fact sheets you can read and download.
I treat invasive plants with a
little grain of salt, as I control the growth of all of my plants.
Either with severe pruning and thinning, or by growing them in
controlled environments, and in pots or on trellises. Some of my
plants are considered invasive in regions, but I have not found them
to be. I deadhead as much as I can so that a plant doesn't go to
seed, but will probably re-bloom for me. There are a lot of
destructive plants growing wild and crowding out roadways, damaging
pipes and structures, and strangling native growth, so it's wise to
just not grow those or at least, don't grow those in an open area on
large properties or in wildflower or prairie gardens.
Native plants for each state are
the best choice. You know they thrive in your region. For Native
Plants and Wildflowers that flourish in Zone 6 in Pennsylvania, visit
USDA Native Perennial Plants Database. You can search for native
plants for any state and region.
Check out this page
for more growing information
USDA Hardiness Zones 5/6 - Native Plants and Their Attributes
Below is my list of perennial
plants and trees appropriate for growing in Pittsburgh and other
Zone 6 areas. Check for the proper variety of these plants.
Some varieties won't make it through your winter, no matter what the
Zone hardiness is for that species. Some types are hardy, some types
are primadonnas. This is not an exhaustive list. It's mostly what I
have successfully grown in both of my own Zones 5 and 6b gardens.
The * next to the plant
designates that the species has proven hardy in my gardens in
Pittsburgh. In-ground and in pots.
Remember that gardens have "microclimates". So not all
plants designated as "tender perennial" will be hardy (or
not) in every garden, or they may be perfectly hardy. My gardens
have sheltered areas, or "rooms". I can grow a lot of
things in my microclimate in those sheltered spaces that normally do
not survive winter. Using this logic, there can also be
microclimates in your gardens that can reduce the cold hardiness -
windy, wet, damp, chilly, exposed, sloping high or low, growing in
containers, etc. I also grow plants designated for shady areas in
the sun, and vice versa. Researching your plants and knowing your
garden spaces is essential. I can grow some borderline trees that
are winter hardy by clustering potted trees in a sheltered area
behind a fence, and against a warm exterior wall.
Check your plant names and
hardiness zone listed for them on the USDA cold hardiness zone
to be sure the variety you pick is perennial in your zone.
6 Flowering Plants and Shrubs
*Rose of Sharon
* Giant Hibiscus
*Milkweed and butterfly weed
*Bee Balm (Monarda)
St. John's Wort
Liatris "Blazing Star"
Red Hot Poker
* Shrub, tree, and climbing Roses
Jack in the Pulpit
Culinary and Medicinal Herbs and Veggies
St. John's Wort
- edible and medicinal weed
*Purslane - edible weed
Black Cohosh, Blue Cohosh
*Roses - Hips are packed with vit. C, petals used in teas
*Scallions/ green onions
Foliage Plants and Ferns (some of these plants also have
*Dwarf hardy Bamboo
*Dwarf Yucca - "Color Guard"
*New York Fern
*Wood FernSword Fern
Flowering Perennial Bulbs, Rhizomes, Tubers and Roots
flowering bulbs, except for tropical varieties, are hardy in
the colder regions, where chill hours are quite essential to
spring flowering. Within all groups are several examples of
zone differences between varieties.
*lily of the valley
Flowering and Fruiting Vines
varieties of Honeysuckle
*non-invasive varieties of Wisteria
*snow in summer
*Blue and White Star Creeper (Amsonia)
*Snow on The Mountain
*Opuntia (prickly pear cactus)
*Dwarf Yucca - "Color Guard" and a few others
*Hens and Chicks
Conifers and Ornamental Evergreen Plants, Shrubs, Trees
Trees - Dwarf varieties grown in pots included on the list.
ornamental and fruit trees can be dwarfed for small spaces,
and many can be trellised and espaliered
to conserve space , and used to decorate walls,
structures, and fences.
*Purple Leaf Plum ("Thundercloud")
*Chinese Fringe Tree
*Ornamental Plum trees
*Japanese Weeping cherry
*Snow Fountains Cherry
Golden Rain Tree
Hardy crape myrtle
of Perennial Fruit Trees, plants and shrubs. Edible and
- several types of June- and everbering
*cherries - many types
I haven't tested cold hardiness of the hardiest yet.... my
trees are going into their first winter. All are growing in
The following fig
varieties are said to make it through Pittsburgh's Zone
6 winters, with shelter and protection:
Brown Turkey Fig, Chicago Hardy Fig, Celeste Fig, Kadota
- A borderline
zone variety's hardiness depends upon the actual severity of
winter weather in the northeast. And yes, where it's at in
your own backyard. Some zone 7 figs, like Kadota and Celeste,
can survive Zone 6 winters with protection.
Fig trees in the northern states should be wrapped, covered,
or trenched in fall. When all the leaves drop, the trees can
be brought indoors, or stored in a cold garage, basement or
shed during the entire winter dormancy.
Dormant plants do not need
sunlight, and very little water until they break dormancy in
early Spring. Pruning can be done during dormancy. Fig trees
can be planted outdoors early... as soon as they break
dormancy and the ground can be worked. They need a long
growing season to produce the main fall crop.
Ornamental Grasses - planted
in soil, bogs, in marginal bog areas and in or around ponds
*Fescue - "Elijah Blue" , all festuccas/fescue
*Japanese Blood Grass
*Black Mondo Grass
and Butterfly Plants
For The Bees
Sources, other than my own
Pa. Dept. of Natural Resources
Penn State Cooperative Extension
Better Homes and Gardens
photos and design ©2020 marysbloomers.com
All rights reserved.