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Showing posts from March, 2012

Some Questions About Japanese Beetles

David Cappaert, Michigan State University,
Photo 1: Japanese beetle grub

Jeffrey Hahn, Asst. Extension Entomologist

There have been a lot of questions concerning Japanese beetles (JB) as we go into the 2012 growing season.  JB has been increasing in numbers over the last four or five years, especially in the Twin Cities area, although JB are also starting to be found more commonly in other areas of the state as well.  They can be challenging to control and people will take any steps they can to reduce their numbers in their gardens and yards.

The first question people ask is how bad are JB going to be this year.  There isn't an easy answer to that question and it undoubtedly will vary according to where you live.  If JB was abundant last year, there is a good chance they will be common again this summer.  However, a factor that can have an impact on JB numbers is soil moisture.   The eggs and the young grubs have a harder time surviving in dry soil so if dry conditions …

A Bee Lawn: How to Have an Insect Haven in Your Lawn

Mary Meyer, extension horticulturist and professor, University of Minnesota

As a grass researcher and lover of grass, I enjoy and appreciate a lawn. I also know there is great value in a lawn that allows and encourages a diversity of plant species that will benefit pollinators while looking neat and tidy for our neighbors to accept. First of all, let me state that I have had more questions on how to NOT attract bees to lawns, and how to eliminate bee plants (such as creeping Charlie) than on how to attract bees to lawns. When you have young children sitting on the lawn, rolling on the lawn and playing outside, bees can be a problem that you want to avoid. But for adults and taller folks, we can easily avoid bees in lawns. And knowing that bees are vital pollinators that need our help with increased habitat, I urge you to look at your lawn and consider where part of it may become a haven for bees and other important pollinators.

What is a bee lawn?

My definition of a bee lawn is a comb…

Watering orchids - roots tell the story

Karl Foord - University of Minnesota Extension

It is not often that a plant can through a visual color change indicate its need for water, however the aerial roots of tropical epiphytic orchids indeed do. Epiphytes are plants that grow on other plants or structures but are not parasitic (Photo 1).

Photo credit
Photo 1: Epiphytes on Tree

They derive their moisture and nutrients from air, rain and nearby debris. Most of the orchids used as house plants are tropical epiphytes.
The roots of these plants not only serve to anchor the plant to trees or stone, they also function as water storage units capturing water during rain events. The roots have a unique structure that enables them to absorb and store water. Phil Gates, a botanist at Durham University in the UK, has a blog entitled, Beyond the Human Eye - An insight into a microscopic world, invisible to the unaided human eye. He has sectioned and photographed an orchid root (Photo 2).

Phil Gates
Photo 2: Sectioned orchid root

The x…

Avoid Damping Off of Seedlings

M. Grabowski, University of Minnesota Extension

M. Grabowski, UMN Extension
Photo 1: Cucumber seedlings suffering from damping off
Damping off is a fungal disease caused most commonly by the fungi Rhizoctonia spp., Pythium spp., and Fusarium spp. All three of these fungi survive quite well in soil and plant debris. Since the tissue of young seedlings is soft and easy to infect, these pathogens can attack a wide variety of flowers and vegetables when they are seedlings. Damping off fungi can kill the seed before it emerges from the soil or it can attack the young stem and new leaves, resulting in tan mushy spots, pinched, rotted stems, and often complete collapse of the seedling. Once an infection has begun, the damping off fungi can move through the potting mix to infect nearby seedlings. Quite often a large section or an entire tray of seedlings is killed by damping off, resulting in few or no surviving seedlings to grow into mature plants.

Damping off is only a disease of seedlings. Onc…