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Showing posts from 2016

Caring for Your Norfolk Island Pine

By Beth Berlin, University of Minnesota Extension
Many people will receive a Norfolk Island Pine for the holidays. These beautiful evergreen trees can become a wonderful houseplant with the right care for many years to come.
Norfolk Island Pines, Araucaria heterophylla, is not actually a pine tree. It is a coniferous evergreen native to Norfolk Island in the South Pacific near Australia.  They have short dark green needle-like leaves with broad spanning branches that give it a tiered appearance.  In its native climate they can reach 200 feet tall with a ten foot diameter trunk.  As a houseplant it is very slow growing, only growing about 3-6 inches per year, but can reach a height of 5-8 feet.
To care for a Norfolk Island Pine, place it in a bright, sunny location. Be sure to spin your plant each week so that it doesn’t start to lean or grow towards the window and light. In general Norfolk Island Pines can be kept at 65-72°F, but it is important not to expose them to extremes, both ho…

Weeds in the Turf Lawn: Invasive Nuisances or Sources of Forage?

By James Wolfin, Graduate Research Assistant

The turf lawn accounts for nearly 2% of the continental United States land cover, and has become engrained in the architecture of many United States neighborhoods and landscapes.  As urban and suburban areas continue to expand, we can expect this number to increase as many yards, store fronts, and commercial buildings are installed to accompany properties.

While the planting of turf lawns alongside most properties is a standard practice, the management practices and personal perceptions of those managing lawns are variable.  Lawns differ in the level of input that is imparted by the landowner.  Input generally refers to the effort that is directed towards maintaining the aesthetics of the lawn, normally in the form of mowing, watering, weeding, and fertilizing.  While each of these practices are generally required to ensure proper turf health, how frequently inputs are applied can vary greatly.  Practicing responsible lawn maintenance pract…

Preparing your trees for winter

By Gary Wyatt, Extension Educator - Agroforestry and Bioenergy
From http://www.myminnesotawoods.umn.edu


It may not seem like it with the unseasonably warm temperatures we’ve been experiencing this fall,
but winter is on its way. Are your trees and perennials prepared for the changes ahead?
Perennial shrubs and trees, especially conifers, should be watered generously until the soil freezes. Mulching trees will help reduce winter root damage.

Young maples and thin barked trees may benefit from some kind of sunscald protection to prevent the bark from cracking this winter and spring. This protection is usually in the form of a plastic tube or tree wrap which is removed in spring. These practices can also help in reducing winter animal damage. Read more ....



What to do about fruit flies

Jeffrey Hahn, Extension Entomologist

Fruit flies, Drosophila spp., can be a common insect in homes during fall. Also called vinegar or pomace flies, they are small, about 1/8th inch long with a brownish body and a dark colored abdomen. Fruit flies typically have red eyes which are a good feature to help distinguish them
between other indoors flies (however this color fades once the flies are dead).

Be careful as there are other small-sized flies, such as fungus gnats, moth flies, and humpbacked flies, that could be confused with fruit flies. There is even a couple of species of fruit flies with dark colored eyes that are a little larger than an average fruit fly. The control varies depending on what the type of fly is found so it is important to verify the insect you are finding in your home.

Fruit flies are associated with fermenting, moist, relatively undisturbed organic material. This is often due to overripe and decaying fruits and vegetables but can also be in a variety o…

2017 Minnesota Gardening Calendar available

The 2017 Minnesota Gardening Calendar is a great resource for the gardeners in your life! It is a terrific holiday gift, housewarming gift (especially new homeowners who have never owned a yard), host gift, or just a thanks-for-watching-my-plants gift. Whatever your reason, this is the time to get your copies. Buy online or in person from selected University of Minnesota bookstores and the Minnesota Landscape Arboretum gift shop. Written by Extension Horticulturists. the 2017 Minnesota Gardening Calendar features monthly lawn care and gardening. Featured writer and turf extension Educator Sam Bauer contributes an informative article called Water Saving Strategies for Home Lawns and provides guidance on reducing our water use without sacrificing a great looking lawn. And then there are the photos! Each month features a timely photo that reminds us Minnesota landscapes are beautiful at any time of the year!



There's still time for dormant seeding - a good option for good lawn next spring

“I know I missed the best time for seeding my lawn which is mid-August to mid-September. Can I still seed even though it’s October and temperatures have been mild?” According to turfgrass Extension educator, Sam Bauer, “Just wait, dormant seeding in November will be your best option." True temperatures are warm during the month of October, and a homeowner could get some seed germination before winter snows, but this is touch-and-go. Bauer recommends saving your time and money and wait dormant seed in mid- to end-November. Read more.

Temperature Control in a Bumble Bee Nest

Karl Foord - Extension Educator, Horticulture

The previous post linked to a video showing a new born bumble bee. The following video is of the same nest but involves a different observation.

To view and photograph the nest I had to pull away the straw covering the nest. This exposed the nest to the direct sun and evidently increased the temperature of the nest beyond the acceptable range of the worker bees. In this video a worker bumble bee uses her wings to fan and cool the nest. The wings are moving so fast that they practically disappear, a little like airplane propellers.

To give a sense of perspective, the engine on a propeller driven airplane rotates some 43 times in one second. I timed the wing speed of bumble bees in one of my videos to 172 beats per second. No wonder the wings are impossible to see when filmed at regular speed. In the second half of the video I have slowed the speed of the action by a factor of 4 and it is still difficult to see the wings moving. You can see …

Observe a Newborn Bumble Bee

Karl Foord Extension Educator, Horticulture

Some of the folks maintaining the Display Garden located on the St. Paul Campus discovered a Two Spotted Bumble Bee nest (Bombus bimaculatus). On June 5th I found the nest with the help of Julie Weisenhorn and took some video.

This is a young nest and relatively early in the season, so the worker bumble bees are significantly smaller than the Queen. This bee is identified in the video.

In addition a new born bumble bee appears from under the top end of the nest. This individual can be recognized by the white hair covering its body. Later the hair in some places will turn golden and in other places black. Other evidence that this is a new born come from the shape of its wings. Notice that the wings on this bee are flat and curve around the base of the abdomen. The bee will proceed to pump hemolymph (the fluid of their circulatory system) into the veins of the wings. This will will expand and straighten the wings after which they will dry and …

Remove white mold infected annuals

M. Grabowski, UMN Extension Educator

White mold is a plant disease caused by the fungus, Sclerotinia sclerotiorum. This pathogen is capable of infecting over 400 plant species. Flower garden favorites like zinnia, petunia, salvia, and snap dragon are highly susceptible to white mold. In the vegetable garden, tomatoes, green beans, lettuce and cabbage can all be infected. Removal of infected plants is a critical management strategy for white mold. The pathogen can survive up to 8 years in specialized resting structures produced on infected plant material. 


Plants infected with white mold often wilt and die. The lower stems of these plants will be tan and dry. If the humidity is high, white fluffy clumps of fungal growth may be seen on the stems. Gardeners may also see small, rough, black structures that look like seeds or peppercorns forming along stems or inside of them. These are special resting structures, called sclerotia that are created by the fungus. Sclerotia can survive in the …

Orb weaving spiders

Jeffrey Hahn, Extension Entomologist

Spiders are particularly common around homes and gardens during late summer and fall. Undoubtedly the most common types are the orb weaving spiders (family Araneidae). These spiders can be recognized from the large, circular, flat webs that they construct. They vary in size although many are moderate to large sized.  Some species are very colorful. They typically have round, plump abdomens with relatively short stout legs.

There are two common groups of orb weaving spiders that people commonly encountered, spiders in the genus Argiope and those belonging to the genus Araneus.

Argiope spiders, also referred to garden spiders are large with a body length up to one inch long, and conspicuously colored yellow and black or silver, yellow and black. Their abdomen is more oval compared to most orb weavers.

Araneus species are typically moderate sized.  They can be either brownish or colored brightly, especially orange or yellow.  Their abdomens are general…

EAB found in Duluth again

Jeffrey Hahn, Extension Entomologist

(The following information is modified from a Minnesota Department of Agriculture news release).

The Minnesota Department of Agriculture (MDA) is issuing an emergency quarantine for the southeastern portion of St. Louis County (see below map) after confirming a second emerald ash borer (EAB) detection within the city of Duluth. EAB was found in Superior, Wisconsin across Lake Superior from Duluth in August, 2013. It was first found in Duluth in October, 2015 on Park Pointe; the quarantine at that time was restricted to only this island.

The emergency EAB quarantine limits the movement of firewood and ash material out of the quarantined area of the county. The quarantined area now runs from MN Highway 33/US Highway 53 on the west to the Lake County border on the east. The northern border of the quarantine runs from US Highway 53 along Three Lakes Road (County Highway 49) east to the intersection of Vermilion Trail. It then continues along t…

EAB is found in Dodge County

Jeffrey Hahn, Extension

(The following information is modified from a Minnesota Department of Agriculture news release).

The Minnesota Department of Agriculture (MDA) has placed Dodge County under an emergency quarantine after emerald ash borer (EAB) was found in the city of Kasson last week. Kasson is about 13 miles west of the nearest known EAB infestation in Rochester (Olmstead County). The EAB was found in a United States Department of Agriculture (USDA) trap. MDA staff has since conducted a search of the area and discovered an EAB infested tree.

Because this is the first time EAB has been identified in Dodge County, the MDA is enacting an emergency quarantine to limit the movement of firewood and ash material out of the county. This will reduce the risk of further spreading the tree-killing insect. Currently 12 other Minnesota counties and Park Point in the city of Duluth are under quarantine to prevent the spread of the emerald ash borer.

The biggest risk of spreading EAB co…

Turf War: Overwatering our lawns is sucking up our water supply (Star Tribune)

Sam Bauer, Extension Educator
Over the weekend the Star Tribune ran an article discussing lawn watering and its impacts on our pocketbooks and our water supply.  The author, Hannah Covington, spent a day with our Extension Turfgrass Science Team as we conducted irrigation audits for several homeowners in Apple Valley.  This study is sponsored by the Metropolitan Council with the ultimate goal of reducing the amount of water being applied to our home landscapes, much of which is wasted water.  With this study, we are conducting a survey (which many of you filled out- thank you!) and we are also selecting residents in the 7-county Metro Area to have their home irrigation systems being audited.  The audits entail checking irrigation system components, conducting performance testing and making recommendations on how to save water through basic irrigation system adjustments.  You can read more about how to properly conduct an audit of your irrigation system in the previous Yard and Garden…

Water Wisely: Auditing Home Lawn Irrigation Systems

Sam Bauer, Extension Educator

Auditing irrigation systems is an important practice for maximizing water use efficiency in the home landscape.  Audits entail checking for irrigation uniformity and converting minutes of irrigation to a depth in inches of water applied.   A full irrigation audit should be conducted at least every three years, although proper irrigation requires more frequent monitoring of irrigation system components to ensure that everything is working properly.  Broken sprinkler heads and irrigation of impervious surfaces are very common issues that we observe and these must be repaired in a timely manner. 
Basic Irrigation Auditing Procedure
Step 1: System inspection Run each irrigation zone.  Look for broken sprinklers, low water pressure and arcs or angles of water spray that are distributing water where it is not needed (i.e. on streets or driveways).  Replace sprinklers, correct water pressure issues, and make adjustments to the water distribution so your system is…

Bacterial diseases of vegetables

M. Grabowski, UMN Extension Educator
The high heat and humidity this summer, combined with multiple heavy rain events have created ideal conditions for many bacterial plant pathogens to multiply and spread. This is especially evident in the vegetable garden, where black rot can be easily found on cabbage, kale, and broccoli, beans bear spots and browning from bacterial leaf blights, and tomato and peppers are spotted by bacterial spot.
Bacterial plant pathogens have several unique features that make them good plant pathogens. Many are able to infect seed and can be introduced into the garden unseen on infected seed or transplants.

Bacteria are covered in a sticky coating and are easily spread through the garden on hands, tools, and insects. Many bacterial plant pathogens are also easily spread by splashing rain or sprinkler irrigation. Bacteria infect the plant through natural openings or wounds. They multiply within infected plant tissue and can survive from one growing season to t…

Springtails in homes

Jeffrey Hahn, Extension Entomologist

A consequence of the abundant rainfall that most of Minnesota has received has been an increase of springtails found in homes and other buildings. Springtails are small insects that are associated with moisture. They range in size from 1/16 - 1/8 inch in length. Most are slender, although some are round and stout. They are typically dark colored, gray, black or brown, but some are white and some even iridescent and brightly colored. Springtails lack wings but do have the ability to jump.

Springtails as a group are very numerous, living in a variety of moist habitats including in soil, leaf litter, mulch, decaying wood, and around bark where they feed on fungi, pollen, algae, and decaying plant matter. They can live inside buildings when high moisture exits, e.g. around plumbing leaks. They can also seek shelter indoors when areas around the outside of the home become excessively wet. Fortunately, regardless of the number that are seen, t…

A bad year for bur oak blight

M. Grabowski, UMN Extension Educator
This summer many bur oak trees are suffering significant leaf browning and death due to bur oak blight. Frequent rain events at the time new leaves were reaching their mature size created highly favorable conditions for infection by the fungus that causes bur oak blight. For property owners with affected bur oak trees, now is the time to submit a sample for diagnosis. If disease is severe, contact an arborist now to schedule treatment for bur oak blight in spring of 2017.
Bur oak blight, often referred to as BOB, is a plant disease caused by the fungus Tubakia iowensis. The BOB fungus survives the winter on infected leaves that remain attached within the tree canopy.  In wet spring weather, the fungus releases spores that start infections on new leaves. Although the infections occur in spring, the most obvious symptoms do not appear until the end of July or early August. Initially, dark discolored lines can be seen forming along major leaf veins. As…

Useful Tools to Determine Soil Moisture Status II: Gypsum blocks and others

Karl Foord, Extension Educator - Horticulture

Another tool for measuring soil moisture are gypsum blocks. Gypsum is a porous material that equilibrates with soil water similar to the ceramic tips of the tensiometers. In this case two electrodes are embedding in the gypsum block in a cylindrical or parallel mode (Figure 1). The commercial product often has a perforated metal covering to protect the gypsum (Figure 2).
This system functions by connecting to a meter that measures the resistance between the two electrodes embedded in the gypsum. Water is a good conductor of electricity. As soil water decreases due to plant draw down resistance increases and visa versa when soil water increases resistance decreases. The electrodes can be permanently connected to a box (Figure 3) or temporarily connected to a portable meter (Figure 4).




Placement of gypsum blocks follows the same strategy that is used with tensiometers. One block is placed in the middle of the fibrous root zone and another b…

Useful Tools to Determine Soil Moisture I: Tensiometers

Karl Foord, Extension Educator - Horticulture

Generally the most limiting element in maintaining uniform plant growth and high quality produce is water. A plant can be experiencing water deficit prior to our observation of wilting. Such deficits can lead to slower growth rates, pollen mortality and loss of flowers, lighter fruit weight, and blossom end rot, among others. It is best to avoid having the plant experience any water deficit.

However, how can you know that the plant is in water deficit? The truth is that you can only know this indirectly. One can estimate soil water content by taking a soil surface sample and feeling the water content with your hand; this will of course vary with soil type and again extrapolates the soil water content within the root zone. This method will require consistent attention to growing conditions including temperature humidity and rainfall.

What  other options might allow a more direct sampling of soil water content within the rooting zone of the …

Bugs on milkweed

Jeffrey Hahn, Extension Entomologist

Home gardeners have been finding orange and black insects on their milkweed and related plants. Although some people think they are boxelder bugs, they are actually insects called large milkweed bugs, Oncopeltus fasciatus.

Adults grow as large as ¾ inch long. They are mostly orange and black including a black horizontal band across the center of the body and black on the end of the wings (the membranous section). A portion of the head is reddish orange. The immature nymphs are mostly orange with black wing pads and smaller than the adults.

Large milkweed bugs prefer to feed on common milkweed but will also feed on other related species. They often feed in large groups making them conspicuous on the plants. Despite their appearance, they do not harm milkweed nor any insects, like monarchs, they may also be on the plants. No action is necessary if large milkweed bugs are found in your garden.

Sap beetles in gardens

Jeffrey Hahn, Extension Entomologist

Some home gardeners have been finding sap beetles in some of their fruits and vegetables. These beetles are generally small, between 1/8 – ¼ inch long, oval, and dark colored. Some sap beetles have orange spots on their wing covers.
Sap beetles are attracted to fermenting smells and will attack fruits and vegetables, such as tomatoes, sweet corn, raspberries, strawberries, and muskmelons, that are damaged, overripe, or rotting. They often are just a nuisance, although it is possible for them to move to and damage ripening fruit.

The best management for sap beetles is to pick fruits and vegetables regularly as they ripen and remove any damaged or overripe produce in your garden and dispose of by burying or bagging them. This helps eliminate smells that could attract them to your garden. However, once sap beetle find your garden, they can be challenging to eliminate.

Insecticides, such as carbaryl or permethrin, can kill sap
beetles and …

Extension publications: New & Revised in 2016

Lawn Irrigation Survey and Water Saving Strategies

The Metropolitan Council and University of Minnesota Extension are conducting a survey to assess irrigation practices throughout the 7-county Twin Cities Metropolitan Area.  This survey is part of a larger project with the ultimate goal of reducing water use in the home landscape.  You can help us by taking 10-15 minutes to answer a 30 question survey regarding your irrigation practices.  All survey participants will be entered into a drawing for 1 of 10 Visa Gift Cards ($50 value).  Additionally, we are conducting irrigation audits for many properties throughout the Twin Cities.  To have your home irrigation system audited, please complete the survey and indicate that you would like to receive a free audit.  To access the survey, please follow click the hyperlink below: 

RESIDENTIAL IRRIGATION SURVEY

Basic water saving strategies for home lawns Pay attention to the weather During a Minnesota summer we may see heavy periods of rainfall followed by extended periods of drought. Homeowners …

Ground-nesting solitary wasps

Jeff Hahn, Extension Entomologist

There have been a lot of questions about solitary wasps lately. The most common questions have been about cicada killers (Sphecius speciosus) but residents have also seen great golden digger wasps (Sphex ichneumoneus), steel-blue cricket hunters (Chlorion aerarium), and sand wasps (Bembicini).

These wasps are generally large insects. Cicada killers range in size from 1 – 1 ½ inches with a stout body, black and reddish brown thorax, amber colored wings, reddish brown legs, and a black abdomen with yellow bands. Great golden digger wasps are about one inch in length, a more slender body with a black head and thorax covered with short golden hair with a reddish-orange and black abdomen and reddish-orange legs. They have smoky, dark colored wings. Steel-blue cricket hunters are also about one inch in size and relatively slender with iridescent dark blue bodies and wings. Sand wasps are smaller, most are close to ½ inch in length and are typically black a…