If you’re an avid gardener, you have probably seen that the National Arbor Day Foundation has released an updated version of the U.S Department of Agriculture’s hardiness zone map, which was last updated in 1990. The NADF has used data from 5000 National Climatic Data Center stations around the country from the last 15 years to compile their information and come up with the new zone map. The data for both the USDA and the NADF maps are based on average annual low temperatures.

According to the NADF:

The new 2006 arbor day.org Hardiness Zone Map is consistent with the consensus of climate scientists that global warming is underway. Tree planting is among the positive actions that people can take to reverse the trend.
Of course existing trees should continue to be cared for… Certain species may be more vulnerable to stress with the current warmer climate, but they will continue to provide environmental and economic benefits as they grow. It’s just a good idea to consider more tree species diversity for the future.”

Go to their site to view the updated climate zone map, which will appear similar to the picture to the upper right. You can also look up your own climate zone, or compare the old USDA climate zones to the new NADF ones. (I have also included a place to look up your NADF climate zone on this blog entry). While you’re at it, check out the NADF press release, which will explain the process of compiling the new info in more detail.
[ Click here to look up your arborday.org hardiness zone.]

Just because we may be in a slightly different zone doesn’t mean that we can begin planting landscape plants that were meant for the next warmer climate zone. There are more factors than just the minimum temperatures in a given region. There can be any number of things that effect a plant’s ability to survive a winter in Minnesota.
I have been through winters with average temperatures that were devastating to evergreens because of an early ground freeze and a lack of snow cover. The same is true of of other plants, especially ground covers perennials that were planted too late in the season.

A dry fall can also be fatal to plantings (especially evergreens, which can continue to loose moisture in the winter), or plants that entered late fall in a stressed condition. Be sure you find out more about some of the “new introductions” you may read about in your plant catalogues. You can also find out about reliably hardy plants that were developed in Minnesota by checking out the publication “Minnesota Hardy”.http://www.maes.umn.edu/MNHardy/index.asp

According to an article in UMNews, we should proceed with caution.

Both maps are also limited in predicting plant hardiness because they tell us only one thing: the average annual minimum temperature in a given region,” says Rose…..Since the exact conditions for next winter–let alone the next five winters–can’t be predicted, Meyer and Rose recommend that Minnesota gardeners continue to choose landscape plants carefully. Less-hardy plants may require special care, including the application of winter mulch.

Every year I get several calls from my customers asking “what’s that slimy stuff on my growing in my bark? It looks like a dog threw up in my shrub bed!” That “slimy stuff” has a very apt name. It is called slime mold. It may look vicious, but it is harmless. The following text was taken from the Sylva Corporation. The photo of the slime mold was taken in my yard.

With the rains and heat of summer come the vast array of slime molds (also known as dog vomit fungi) appearing in mulch. They appear in several sizes and colors with no definite shape.The mold may change on a daily basis from a bright yellow netting to a tan powder to a dark brown dried blob.
Slime molds get their nutrients from dead organic matter, including mulch.Although slime molds may grow on plants, they do not harm them.Slime molds will eventually disappear on their own. If you want to speed this process, rake the mulch to prevent air drying. For additional information regarding these molds, try the following websites: http://www.waynesworld.palomar.edu/slime1.htm
http://www.coopext.colostate.edu//TRA/PLANTS/slime.html
http://www.herbarium.usu.edu/fungi/FunFacts/SlimeMold.htm

Those doggone walnuts. They are one of our most valuable hardwood tree species, but they can be a real nuisance in the home landscape. Each year, several people will ask me why they can’t seem to get anything to grow under their walnut tree. Just the other day I was at a customer’s house looking at some problem plants and sure enough, they were trying to grow right under a walnut tree.

Walnuts release a chemical into the soil called juglone. Juglone is present in all parts of the tree, but can be especially high in the roots and walnut hulls. The highest concentration in the soil is directly beneath the canopy of the tree, but it can be present in lesser concentrations anywhere the roots are present (which can be out as far as the tree is tall). The presence of juglone can also be affected by soil type, with sandy well drained soils tending to have less of it present.
Juglone can be toxic and even fatal to some plants, while others don’t seen to be affected by it. Affected plants show signs of wilting, yellow leaves, stunted growth, and eventually death.

So what’s the solution?

1) Susceptible plants can be planted in above ground containers or raised beds. If you build a raised bed, make sure you line it with plastic so the roots won’t grow up in to the soil or you’ll have the same problem all over again. Make sure you rake up any leaves or hulls that end up in the bed.
2) Cutting down the walnut tree can be a good long term solution, but the decaying roots will still release juglone into the soil, and it could be several years before the juglone is out of the soil.
3) Plant susceptible plants as far from the drip line as you can. The farther the better.
4) The most obvious solution is to install plants that are more resistant to juglone. The thing is, there hasn’t been any proven method of determining which plants are truly resistant. Any research I found on plant tolerance was based on simple observation. I compiled the following list of tolerant/intolerant plants using my own observations and checking out the university extension sites of Cornell, Purdue, Michigan State, University of Minnesota, Ohio State, and the Morton Arboretum. I have only included woody landscape plants. For a complete list including annuals, perennials and vegetables, click on the hyperlink to each of the sites listed above.
Just because a plant is listed as susceptible or non-susceptible does not guarantee that it will grow under a walnut tree.Therefore, I listed plants as “more tolerant” or “less tolerant”. I found a few plants that were listed as tolerant on one list and non-tolerant on another list. The list is compiled of plants that the sources had in common.

Trees
Less tolerant: White Birch, Hackberry, Linden, Pine (in general) Black Alder, Magnolia, Norway Spruce, Crabapple, Apple, Silver Maple, Arborvitae.
More tolerant: Catalpa, Eastern Red Cedar, Hemlock, Elm, Locust, Red Maple, Sugar Maple, Redbud, Poplar, White oak, Red oak, Serviceberry, Hawthorn, Beech, Sycamore,

Shrubs
Less tolerant: Azalea, Rhododendron, Black and Red chokeberry, Hydrangea, Lilac, Mugo pine, Potentilla, Cotoneaster, Yew.
More tolerant: Some Viburnums, Juniper. St Johnswort, Euonymus, Forsythia, Honeysuckle, Ninebark.

If you’re passing through Northfield on Lincoln Street this Spring, check out a renovation project we did on a home close to the corner of Lincoln Street and Lincoln Lane. For those of you familiar with Northfield, you probably noticed our trucks parked in front of the house (across from the St. Olaf practice fields) for a good part of last summer.
Many years ago a previous owner had done a nice job of landscaping on this home, but time took its toll, and it was time to start over. They contacted local landscape architect Spencer Jones, who came up with an ambitious landscape plan to renovate their entire front yard. The plan included a bluestone patio, an upper lawn area, the landscape plantings, several retaining walls, and three step systems.

We had Jim Gleason and his crew from American Excavation do the demolition and grading.They started by tearing out all of the existing steps, walkways, and old plantings, including a couple of large shade trees. The only tree left was a huge hackberry that provided shade for the front yard. They then re-graded the whole yard and excavated for the retaining walls that we put in. See the photo at left to view the project after the demolition process. (Click photo to enlarge)

Part of the challenge was to make the retaining walls to look like they had been there for years. The clients had seen some stone that they liked when they were on a trip to Arkansas, and they had it shipped to Northfield to use for the project. It has a unique brown color with a nice aged look (see photo at right). Constructing the walls was the most time-consuming phase of the project, because no two stones were alike.
We also constructed a bluestone patio was constructed out of 1-2″ thick bluestone pieces that came in various square and rectangular sizes (called an ashlar pattern). They are quarried out of New York and Pennsylvania.

We finished up the landscaping and sodding in the early fall. It will be exciting to see their new landscaping come to life this Spring!

I will give you an update this spring with photos of the finished project.

Left: Tony Line and Brian Blackford of Straight Line Concrete working on one of the concrete step systems. There is a total of 3 step systems, connected with exposed aggregate landings and walkways.

Earlier I wrote about the construction of Amerman Pavilion and the great volunteer efforts of dozens of people willing to donate their time, labor, and expertise to see the see the project through.

In addition to the pavilion I was able to supervise the construction of the WINGS Oasis, designed by Spencer Jones of Northfield. The Oasis is a misting station located next to Amerman Pavilion. In case you don’t know what a misting station is, it is basically a vertical pole that emits a fine spray of water out of nozzles placed at different heights on the pole. Our station consists of a brick paver patio with 3 misting poles placed in a triangular pattern which, at the push of a button, emit a fine spray that cools off joggers, soccer players or even your pet dog. (Sorry, it doesn’t cool off hot tempers) The brick pavers are Eco-friendly, which means that they allow the water from the misting poles to soak in to the ground, thus preventing water run-off. It also includes a handicap accessible drinking fountain, a stone seat-wall and landscaping.
A lot of thanks goes to WINGS of Northfield for the generous support they provided for the Oasis. The generosity of this organization made a big difference in this project, and I’m sure their stated mission of “improving the lives of women and children in Northfield area” will continue be felt as they continue to be involved in the Northfield community.

Click on photos to enlarge

Left: Ben Bauman of Grove Landscaping prepares the sub base for the brick eco-pavers
Center: John and his Dad Jim Pokorney keeping the brick layers busy
Right: Three of the volunteers discussing the project (or is that last night’s Raiders game they’re talking about?)

Tony Line and Brian Blackford of Straight Line Concrete did the cement work, and Mark Welch of Welch Plumbing was generous with his time, installing the water supply lines to the misting heads and drinking fountain. The trees, shrubs (supplied by Knecht’s nursery) and pavers were installed by our volunteers on a Saturday in early November, about a week before the snow started flying.

It was my privilege to work with several great volunteers on both the landscaping and the construction of the patio/misting station, including the members of the steering committee and the Northfield Soccer Association. The soccer community and the citizens of Northfield owe them and all the volunteers a big thank you for their efforts in getting this project moving forward.

This spring we will continue the work to finish up the project. Yet to come is a dry stone retaining wall, construction of a burm and more landscaping. The misting poles should be coming soon. I will keep you up to date as we finish up the project.

The pavilion and the misting station are great additions to the soccer complex. It is yet another one of those things that set Northfield (and our soccer community) apart, to make our town a great place to live and raise a family.

Occasionally I’ll run across something on the web that I’d like to pass on, whether it be an important issue, or just a fun fact. In this case, it’s just a fun fact I found from the U of M Yard and Garden News. There are some deciduous trees that hold their leaves in the winter and don’t drop them until the next spring.Two of my favorites are the Northern pin oak and the Blue beech. I’ve always wondered if there was a word for that keeping-their-leaves-over-the-winter-thing and yes, there is. Read on.

By the way, I recommend that you plant the Northern pin oak and not the Eastern pin oak. Pin oaks (and all oaks in the Red oak genus) are very sensitive to low iron levels in the soil (which shows up as a yellowing of the leaves, a condition known as iron chlorosis) , but the northern pin oak has proved to be more tolerant. In either case always plant a pin oak in a slightly acid soil with good drainage.

What’s Up With That?! Weird Stuff and Fun Facts from the Gardening World
By Nancy Rose

Deciduous trees are supposed to drop their leaves in autumn, right? So why are there still lots of brown leaves clinging tenaciously to certain trees in our neighborhoods and natural areas? In a word: marcescence.

Deciduous trees that hold onto their leaves through the winter are described as marcescent (mahr-CESS-ent). Some tree species are more likely to show marcescense than others. In this region, oak species (Quercus) including pin oak, red oak, and white oak are the most noticeably marcescent trees. American hornbeam, also known as blue beech (Carpinus caroliniana), and ironwood, aka American hophornbeam (Ostrya virginiana) also tend to hold leaves. Other trees such as sugar maple are occasionally marcescent.

In autumn, the leaves of most deciduous trees develop an abscission layer where the petiole (leaf stalk) meets the branch. This allows the leaves to fall off without leaving an open wound on the stem. Dry leaves stay on marcescent trees because the leaves didn’t develop the normal abscission layer in autumn.

Marcescence is often a juvenile trait and may disappear as the tree matures. It also may not affect the entire tree; sometimes leaves persist only on scattered branches. Marcescence is typically based on a tree’s genetics, but sometimes weather plays a part. In years with early freezes tree leaves may be killed before developing an abscission layer, resulting in persistent brown leaves on many trees that aren’t usually marcescent. –Nancy Rose

Thanks, Nancy!

Northfield has the state’s best soccer complex for a town its size, and it continues to get better. The complex is part of Spring Creek park, which is located along Jefferson Parkway on the south side of town. Thanks to the efforts of the steering committee chaired by Rick Estenson, the complex expanded last year to include the construction of Amerman Pavilion and the *WINGS Oasis (*see below. More on the Oasis in a later blog entry). The pavilion was named after local youth soccer coach Jeff Amerman. Jeff was a big contributor to Northfield’s youth soccer program, who passed on in 2005. It is a beautiful facility with room for a concession stand, a huge exterior stainless steel counter , a large sheltered picnic area, and storage for soccer equipment.

Ray Cox, owner of of Northfield Construction, volunteered his time to be the project manager for the construction of the pavilion. He contacted several local contractors to donate their time in constructing the pavilion and also organized the timetable. Phil Olson kept on eye on the project and kept track of the day-to-day progress. I volunteered to oversee the landscaping for the pavilion, ( see photos, click to enlarge) which was accomplished by the efforts of several hard working volunteers. (Any of you guys interested in a job with Grove Landscaping?). Thanks to Knecht’s nursery for donating the plants. Construction started in the Spring of last year, and we finished up the landscaping with a volunteer work day in the first part of November. The work could not have been accomplished without a great group of about 15-20 volunteers.

Make sure you visit Ammerman Pavilion. and see what a great job these volunteers have done! While you’re there, take in a soccer game or two, or three…..

*WINGS (Women In Northfield Giving Support) is a local organization dedicated to improving the lives of women and children in Northfield. They were instumental in making the Oasis possible. You can learn more about them by going to their website through this hyperlink.

Ready——————————Set———————————-Go!!

Thanks to the City of Northfield, Northfield Rotary Club, First National Bank, Northfield Soccer Association Northfield Hospital, Malt-O-Meal, Community Resource Bank, and Wells Fargo Bank for a major portion of the financial support for the construction of the pavilion.

Northfield Steering Committee: Rick Estenson, chair. Charlie Cogan, Jim Pokorney, Kevin O’connell, Margaret Colangelo, Curtis Tiano, Andrew Tiano, Rachael Stets.

If you’re an avid gardener, you have probably seen that the National Arbor Day Foundation has released an updated version of the U.S Department of Agriculture’s hardiness zone map, which was last updated in 1990. The NADF has used data from 5000 National Climatic Data Center stations around the country from the last 15 years to compile their information and come up with the new zone map. The data for both the USDA and the NADF maps are based on average annual low temperatures.

According to the NADF:

The new 2006 arbor day.org Hardiness Zone Map is consistent with the consensus of climate scientists that global warming is underway. Tree planting is among the positive actions that people can take to reverse the trend.
Of course existing trees should continue to be cared for… Certain species may be more vulnerable to stress with the current warmer climate, but they will continue to provide environmental and economic benefits as they grow. It’s just a good idea to consider more tree species diversity for the future.”

Go to their site to view the updated climate zone map, which will appear similar to the picture to the upper right. You can also look up your own climate zone, or compare the old USDA climate zones to the new NADF ones. (I have also included a place to look up your NADF climate zone on this blog entry). While you’re at it, check out the NADF press release, which will explain the process of compiling the new info in more detail.

 Proceed with caution

Just because we may be in a slightly different zone doesn’t mean that we can begin planting landscape plants that were meant for the next warmer climate zone. There are more factors than just the minimum temperatures in a given region. There can be any number of things that effect a plant’s ability to survive a winter in Minnesota.
I have been through winters with average temperatures that were devastating to evergreens because of an early ground freeze and a lack of snow cover. The same is true of of other plants, especially ground covers perennials that were planted too late in the season.

A dry fall can also be fatal to plantings (especially evergreens, which can continue to loose moisture in the winter), or plants that entered late fall in a stressed condition. Be sure you find out more about some of the “new introductions” you may read about in your plant catalogues. You can also find out about reliably hardy plants that were developed in Minnesota by checking out the publication “Minnesota Hardy”.

According to an article in UMNews, we still need to be careful in choosing what we plant.

Both maps are also limited in predicting plant hardiness because they tell us only one thing: the average annual minimum temperature in a given region,” says Rose…..Since the exact conditions for next winter–let alone the next five winters–can’t be predicted, Meyer and Rose recommend that Minnesota gardeners continue to choose landscape plants carefully. Less-hardy plants may require special care, including the application of winter mulch.

Welcome to our new web site! We have been working with Michael Blaha of Organic Arts to create our new site. We’ve added a blog, some new slide-shows and a completely new design. Have a look around! Please Let us know if we can help you.

RSS

You may subscribe to our RSS feed via one of these services. Learn more about RSS here »