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Showing posts from February, 2009

Start out smart – Plant Disease Resistant Vegetable Varieties

Michelle Grabowski, University of Minnesota Extension Educator


Photo 1: Fusarium wilt resistant and susceptible tomato seedlings. Michelle Grabowski

Although winter still holds Minnesota in its icy grasp, smart gardeners are already pouring over seed catalogs and preparing for the season ahead. There are many factors to consider when choosing which vegetable variety to grow this season. One option available to gardeners is disease resistant varieties. These are varieties that have been specially bred or selected for their ability to remain healthy in the presence of a pathogen. Choosing disease resistant vegetable varieties can save the gardener time and money since they will likely not require fungicide sprays or other control measures to prevent the development of fruit rot, leaf spots or other disease problems.


In order to make educated decisions about purchasing disease resistant seed, there are a few terms that gardeners should be familiar with. According to the Ameri…

Three New All-America Rose Selection (AARS) Winners Announced for 2009

David C. Zlesak, University of Minnesota Extension Educator

Photo 1: Carefree Spirit™ shrub rose. David Zlesak
Carefree Spirit™ (shrub rose), Pink Promise™ (hybrid tea rose), and Cinco de Mayo™ (floribunda rose) are the three new All-America Rose Selections (AARS) winners for 2009. These roses have proven themselves as top performers among dozens of entries over two seasons of evaluation at over 20 official test gardens across the country.

Carefree Spirit™ is a cheerful, single-flowered shrub rose with a profusion of red blooms with white eyes throughout the growing season. It is relatively compact in Minnesota, producing a mounded, slightly spreading plant that reaches a couple feet in height and a few feet in width. Carefree Spirit™ is a descendant of the famous Carefree DelightTM and shares its strong disease resistance. Carefree Delight™ is an AARS winner from 1996 and is still very popular in northern landscapes. Both roes were bred in France at Meilland International a…

Seed Savers Garden: A Demonstration of Genetic Variability

David C. Zlesak, Elizabeth Spedaliere, Kathy Bonnett; University of Minnesota Extension Educator and Master Gardeners, respectively

We often hear the saying that saving and starting seeds from hybrids typically leads to inferior plants or plants with too much variability to be worth our while. Even if some variability exists between the seedlings, is it actually so great or the plants so overall inferior that it wouldn’t be worth our effort? To what extent can this be true?
We decided to put this general recommendation to the test and develop a demonstration garden (Seed Savers Garden) at the Master Gardener Education and Research Display Garden at UMore Park in Rosemount, Minnesota to observe what happens.  In the fall of 2007 open pollinated seed was saved off a number of flower and vegetable seed-propagated varieties growing at the University of Minnesota Display and Trial Gardens in St. Paul and the authors’ gardens.  In the spring of 2008 seedlings were started in Mar…

Bird-Nest Wasps

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Photo 1: Birds-nest wasp. Jeff HahnSeveral people have complained of insects damaging their windows and have either described or sent me samples of grass that they found in it.  When asked when they first encountered this, I was told that this was not new from the winter but had occurred last summer or fall.  When the samples were carefully examined, tree crickets were found amongst the grass.  People never noticed any other insects.

However, the tree crickets are not responsible for the grass.  The actually culprit is a sphecid wasp known as Isodontia.  This insect is called bird-nest wasp or grass carrying wasp.  It belongs to a group of sphecid wasps known as thread-waisted wasps.  They have a very thin stalk or waist (actually part of the abdomen) connecting the thorax with the abdomen.  The most common species in Minnesota is Isodontia apicalis.  It measures ½ - 3/4 inch long, is dull black in color…

Garden Calendar for March

David C. Zlesak

Photo 1: Spring flowering shrubs like forsythia have flowers that are ready to open once placed in a warm environment. Cut stems harvested now are easy to force into flower indoors.  David ZlesakAre you ready for some spring blooms?  Consider cutting and brining in some stems for forcing of early spring flowering shrubs like forsythia, pussy willow, and flowering almond.  Stems of these shrubs have flower buds already developed and they are ready to quickly grow and develop in a warm environment after receiving their chilling requirement over winter.  Treat cut stems like standard cut flowers by changing the water frequently and using floral preservative.  Once the flowers begin to appear, their life can be extended by keeping them in a cooler portion of the house, out of direct sunlight, and away from drafts.

Continue to start seeds of bedding plants indoors at the appropriate time for each species.  Different species grow at different rates and the slower o…

What's Up With That?!

David C. Zlesak

“Oh no, are my rhododendrons dying?” or something similar is a startling thought that comes to mind the first time many of us see this characteristic curling on leaves of our rhododendrons in winter. Fortunately, this is a normal response called thermonasty that actually helps our rhododendrons survive this difficult time of year. This curling and drooping of the foliage is in response to cold temperatures (thermo= heat or temperature and nasty= movement to a stimulus that is non-directional). As temperatures warm and cool during winter we can actually observe rhododendron leaves appearing less or more drooped and curled. As a broadleaf evergreen, the large surface area of rhododendron leaves makes them especially vulnerable to drying out during the winter. With the frozen soil this time of year, additional water cannot easily move up the plant and replace what evaporates from the foliage. Curling and drooping to prevent wind from reaching the undersides of the leaves, …

Hakonechloa macra ‘Aureola’ - 2009 Perennial Plant of the Year®

David C. Zlesak, University of Minnesota Extension Educator

Photo 1: Golden hakone grass has been a faithful perennial in this St. Paul garden for several years. David Zlesak

Since 1990, the Perennial Plant Association (PPA) has sponsored the Perennial Plant of the Year® program. Each year members select a superior performing perennial to highlight and promote. Nominations are made by members and winners are decided by ballot. Criteria for nomination includes it must perform well across a wide range of climates, be widely available and easy to propagate in order to supply demand, be relatively low maintenance and easy to grow so the average gardener has a high likelihood at being successful with it, and the plant displays ornamental appeal over a long portion of the growing season.

The 2009 Perennial Plant of the Year® winner is golden hakone grass (macra ‘Aureola'). The golden-green foliage and soft, cascading habit has made this shade tolerant perennial grass a favorite for years a…

The Winter View

Kathy Zuzek, University of Minnesota Extension Educator

It’s official. Winter is more than half over. Are you feeling a bit desperate for warm temperatures and the color green? I spend every February dreaming of a trip to anywhere warm and green or of a kinder, gentler Minnesota where spring actually arrives in February. A quick look out of my window though always reminds me of how truly bleak our long winters would be without woody plants.

Imagine our winters without trees. The word “tundra” comes to mind with endless unbroken landscapes and unchecked winter winds. In fact, the word tundra comes from the Finnish word “tunturri”, meaning treeless plain. Now add trees back into the picture and winter, even in February, is not so bad.
Leaves have fallen from deciduous trees and our focus turns to the sheer size and bold architecture of many tree species. White oak (Quercus alba), swamp white oak (Q. bicolor), bur oak (Q. macropcarpa), red oak (Q. rubra), northern pin oak (Q. ellipsoidalis)…

Escape Winter at the Arboretum’s Orchid Celebration in February

Tracy Walsh
Preview Event is Feb. 12; Exhibit Opens Feb. 13

Chaska, Minn. (Jan. 8, 2008) – Escape the icy blasts of winter and feast your eyes on some exquisite tropical beauties at the Minnesota Landscape Arboretum’s “Totally Orchids – Delight at First Sight” exhibit, opening Friday, Feb. 13, in the Arboretum’s Oswald Visitor Center.

The orchid show, presented by Orchids Limited of Plymouth and the Arboretum, will feature a wide array of unique species and select hybrids, all arranged in attractive planters on eye-level pedestals. The display will continue through March 8 and is free with gate admission ($7 adults).

Several complementary events are planned during the “Totally Orchids” exhibit. Check out these activities (all free with gate admission unless otherwise noted):


A special preview event, “Orchids Tropical Fantasy,” on Thursday evening, Feb. 12, from 5:30 to 8:30 p.m. will provide a first-glance at the orchid exhibit, plus a silent auction, mini-classes and orchid sales. Previe…

Fellow Gardeners—Start Your Seeds

Meleah Maynard, University of Minnesota Master Gardener

In February, as winter seems to drag endlessly on, gardeners who just can’t wait to feel some soil between their fingers finally have something to do: start sowing seeds. While many seeds need to be planted just four to six weeks before being moved outdoors, others that are slower to mature should be started 10 to12 weeks before being transplanted. Timing is important because you want your seedlings to be strong enough to manage on their own, but you don’t want them getting so big that they crowd each other and compete for light, water and nutrients.




Photo 1: Seed racks can be found this time of year at most garden centers. David Zlesak

If you haven’t already got a planting area set up in your basement or other cool, out-of-the-way place, you can easily do that now. Bright windows of course will do, but with the short days this time of year and often limited window space, lights are a great alternative. Be sure to find a spot nea…

Remove Fire Blight Cankers Now to Avoid Disease Problems in the Spring

Michelle Grabowski, University of Minnesota Extension Educator


Photo 1: Fire blight canker on a young apple branch. Michelle Grabowski

This past summer, many Minnesotans noticed dead brown wilted leaves on apple, crabapple and mountain ash trees caused by the bacterial disease known as fire blight (Read Midsummer Trouble for Trees & Shrubs) Although symptoms of fire blight are most apparent in spring and summer months, one of the best times to manage this disease is right now.

Fire blight is caused by the bacteria Erwinia amylovera. This pathogen can infect all members of the Rosaceae family, but most commonly causes problems on apples, crabapples, and mountain ash trees in Minnesota. In the spring and summer months, the fire blight bacteria infects leaves and blossoms, turning them black to brown. The infection often starts at the tip of the branch and moves systemically downward, resulting in entire branches that look blackened or scorched by fire.

Photo 2: Discolored sapwood due t…

Does Cold Kill Bed Bugs?

Jeffrey Hahn, Asst. Extension Entomologist



Photo 1. Bed bug biting. Jeff Hahn

This has been one of the coldest winters in Minnesota in 15 years. And while it can be challenging to find many good things to say about this kind of weather, many people take consolation that the cold temperatures are good for killing insect pests. The most common question lately has been whether putting out furniture or other articles in very cold weather will kill bed bugs.




Photo 2: Fluctuating, cold temperatures may not reliably kill bed bugs. Jeff Hahn

Cold temperatures can kill bed bugs if they are exposed to it long enough and at temperatures that are cold enough. However, there is not a lot research on this topic to say what those exposures and temperatures are. What information is available is contradictory. One researcher in 1966 found that bed bugs can tolerate temperatures around 5o F for a brief time and when acclimated can survive temperatures at or below 32o F for days. This is in contrast to fin…

Low Maintenance Turfgrass Evaluation Study

Research Update - Low Maintenance Turfgrass Evaluation Study – A cooperative project between University of Minnesota Extension and Hennepin County Environmental Services

Bob Mugaas, University of Minnesota Extension Educator

Photo 1: Site conditions prior to low maintenance turfgrass installation, spring 2006. Bob Mugaas

Following is a brief report summarizing the results and observations regarding the establishment and growth of selected fine and tall fescue grass cultivars on an environmentally harsh site. It is located in Spring Park, Minnesota on the shores of Lake Minnetonka. Specifically, it is a nearly fully exposed south facing shoreline embankment between the Lake Minnetonka Sheriff’s Water Patrol (SWP) building and the Spring Park public access (PA). The southerly exposure and very poor, sandy to gravelly soil make this an intensely hot and very dry site. There exists a small lilac hedge along the very top (north) edge of the area adjacent to the parking lot. There are also sev…