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Spider Mite Controls

By Lisa Hagerty, The Real Dirt Editor and MG trainee

The end of summer is nearing, which is apparent with the cooler temperatures we have been feeling the last couple of days. I have at least three trees in my yard that had green leaves only weeks ago, but today the leaves are red. On one hand, it makes me a little sad to see summer fade but on the other, the cooler weather may bring my garden the relief it needs from mites. 

An article written by Howard Russell for MSU Extension, “Spider mite populations thrive in hot dry summers,” tells it exactly the way it is. With the high temperatures of July and August, many of us felt the impact that mites have on a garden. The constant struggle to combat them seems never ending at times. They remind me of tiny vampires as they “suck on the sap that bleeds from the wound” created when they scrape “the leaf surface with their pointed mouthparts” (Russell). A clear sign that spider mites are present is the when the leaves are yellowing, browning, speckling and in worst cases, webbing is visible. Although Russell offers some suggestions on chemical control, he reminds us that the ultimate goal is to preserve and restore natural enemy populations to control the spider mites.

Tomato_mites by lisa hagerty

Tomato_mites by lisa hagerty

Christina DiFonzo of MSU Extension discusses spider mites in southern Michigan in her article, “Potential for spider mites, especially in southern Michigan.” She warns against the potential consequences of treatment, which is a concern for anyone with mites. DiFonzo’s example describes the effects of spider mites on soybean fields, but they can destroy many different vegetables.  According to DiFonzo, the beneficial insect population is killed with the application of insecticides, yet not all mites die. With the absence of the beneficials, the population of the spider mites can flare out of control. Because the spider mite eggs are unharmed and will continue to hatch, we must treat more than once. However, it seems the mites build a resistance to insecticides and the resistance increases with the number of treatments—and round and round we go! At times it all feels like an exercise in futility.

I did find some additional information published by David J. Shetlar at Ohio State University Extension. His article titled, “Spider Mites and Their Control” provides a great deal of good information about spider mites. Although of course, Shetlar references Ohio landscapes, we can be certain that the behavior of Michigan spider mites is much the same. In his article, Shetlar offers five different control methods: Syringing, Quarantine and Inspection, Predators, Soft Pesticides, and finally Miticides. They are noteworthy suggestions. 

Commonly, Shetlar, DiFonzo and Russell agree that early detection is the best control method. Know your plants and recognize the first signs of predatory attack so you can manage and possibly eradicate the mite population before they take over your garden. I do know my plants and I recognized the first signs of spider mites, when my tomato leaves were yellowing. I sprayed them vigorously every other day, yet even with my continuous efforts, a few of my plants continued to decline. 

Tomato mites by Lisa Hagerty

At some point, I realized my Impatiens, Daisies, and miniature Roses that were sitting all around my garden were also suffering from mites, so I integrated them into my routine. It has been a long battle, but with the recent rain, and lower temperatures, I think it is finally under control. Thankfully, I should be able to harvest my tomatoes within the next few weeks.

Tomato_mites by lisa hagerty

References:

https://www.canr.msu.edu/news/spider_mite_populations_thrive_in_hot_dry_summers

https://www.canr.msu.edu/news/potential_for_spider_mites_especially_in_southern_michigan/

https://ohioline.osu.edu/factsheet/HYG-2012-11

Fall Cleanup to Protect Pollinators

By Nate Walton, Michigan State University Extension Master Gardener Coordinator

Along with all of the nationwide enthusiasm for protecting our pollinators have come some really important questions about exactly how best to do it. In some cases the questions are easier to answer because we have an abundance of scientific research, for example, on the effects of insecticides on pollinators. Unfortunately, to answer other questions, we are left with a scarcity of research and we are forced to make generalizations or to leave questions unanswered because, frankly, we don’t know the answer. The question of how to protect overwintering pollinators in our managed landscapes and gardens is one of the latter. Hopefully, all of this debate will inspire more scientific research, but in the meantime we are forced to make generalizations based on what little we know about the overwintering ecology of some of our flower-visiting insects. 

It may seem early to be talking about fall cleanup, but the fact is that many of our pollinators in our area (the Northwest corner of Michigan’s Lower Peninsula) have already found a place to spend the winter by now.  The remainder will be looking for their winter home in the coming months so now is as good a time as any to plan your yard and garden cleanup to protect pollinators. There is no one-size-fits-all solution for protecting our overwintering pollinators. “Pollinators” are an incredibly diverse group and each species has its own preferences for overwintering habitat and emergence timing in the spring. Also, the community of pollinators and how well they survive the winter depends a great deal on geography, climate, and even microclimates in your garden. Finally, the plants themselves in a lawn, perennial bed, and annual flower bed all have specific management needs to keep them at their healthiest going into next year’s season. All of these complications make it virtually impossible to craft recommendations that will satisfy all parties involved. It is up to you to make choices that optimize the protection of pollinators while also meeting your own objectives for your managed landscape or garden.

This tiny bee (<8mm) in the Genus Ceratina will spend the winter in a hollow grass stem or the pithy stem of plants such as sumac or elderberry. (Photo by N. Walton, MSU Extension)

To Clean or Not to Clean?

The most important thing to keep in mind is that by creating overwintering habitat for pollinators in your managed garden space you are committing yourself to caring for those pollinators until next spring or summer when they “wake up” and continue their development. In other words, by creating habitat for overwintering pollinators in the fall, you run the risk of harming them in the spring unless you are very careful during your spring gardening activities. Alternatively, you could create habitat for pollinators in a part of your yard that is less heavily managed, where you perform neither fall nor spring cleanup. 

When to clean?

In the garden space where you do like to tidy things up in the spring and fall, clean up early in fall rather than late so that you don’t risk attracting pollinators that are looking for a winter home. You can then choose to place the leaf litter and stem cuttings from your cleanup activities in another part of the yard to provide habitat for the pollinators there instead. Don’t forget to take extra care with plant material that may be harboring plant pathogens. If you had plants with signs of disease in your garden, you’ll want to separate their leaves and cuttings and destroy them to prevent re-infection of your plants next season. 

What and how to clean?

Many of our pollinators in the Northwest Lower Peninsula of Michigan overwinter under the soil, attached to woody stems, or on tree trunks. These pollinators are not likely to be affected much by typical fall cleanup activities. Some bees and butterflies will spend the winter inside of or attached to the stems of some of our herbaceous perennials and ornamental grasses. If you are cutting these back in the fall, you can carefully bundle or pile the cuttings and place them in an undisturbed area so that those insects can complete their development normally in the spring. 

A few species of moths and butterflies will choose the leaf litter as an overwintering site. If you don’t get around to performing fall cleanup until later in the season (see above), then you can remove the leaves carefully to an undisturbed area. Hand removal of leaves is not likely to cause much harm to the overwintering stages of pollinators. Gentle raking is probably okay as well. Avoid leaf blowers and leaf vacuums, as these are more likely to harm the overwintering stages of pollinators that are sheltered in the leaf litter and around the lower portions of landscape plants. 

What about spring cleaning?

Check back with me in the spring for a follow up to this article. In the meantime, there is a wealth of information about how you can support pollinators by withholding pesticide sprays, providing flowering plants, nesting resources, and overwintering habitat, all available at migarden.msu.edu and pollinators.msu.edu.

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Doug Tallamy in NW lower Michigan

Morgan Composting: The Home of Dairy Doo

Doug Tallamy in NW lower Michigan

By Cheryl A. Gross, AEMG

Have you read Bringing Nature Home by Doug Tallamy?  If not, I suggest you do.  It is an extremely important gardening book of our time.  It was published in 2007. In 2016, Tallamy published The Living Landscape with Rick Darke.  In February 2020, Timber Press will be releasing Tallamy’s third book, Nature’s Best Hope.  The release of his third book is eagerly anticipated.

Dr. Douglas Tallamy is an entomologist at the University of Delaware.  His research about the relationship between insects and plants was a breakthrough for environmental and ecosystem gardeners.  Generally speaking, entomologists are not “Rock Stars” however, publishing Bringing Nature Home changed Dr. Tallamy’s life dramatically.  He is highly respected for his research and a sought-after speaker. He was the Keynote speaker at the Wildflower Association of Michigan’s March 2019 Wildflower Conference and the speaker at Saving Birds Thru Habitat’s Annual Fundraising event on August 24th. We are fortunate to have him visit Michigan frequently.

Tallamy’s research makes the very strong connection between insects and the native plants that host them.  These relationships are critical to the food web. We know that birds, 98% of them, feed their young insects. (The other 2% eat fish.  Not one baby bird is raised on seeds.) We know that a clutch of chickadees needs hundreds of insects a day and 6,000-9,000 insects to successfully fledge.  We know that most insects are specialists in that they can survive on only one type of plant, i.e. the Monarch butterfly caterpillar that can only eat plants in the milkweed family.  Monarchs aren’t the only picky eater by a long shot.

The plants that best support the food web are native to the region.  Coevolution between plants and insects has been going on for millions of years.  Introduced plants simply cannot provide the same ecological services. Too few insects are adapted to them.  No insect biomass, no birds. Introduced plants may be a lovely fashion, but they are useless at feeding birds.  Some introduced plants may be harmless except they take space away from a native plant. However, some alien plants escape and are causing severe ecological damage.  Some invasive plants may be well known. Myrtle, Lily of the Valley, Japanese Barberry, Kudzu, Buckthorn, and Autumn Olive are known to be problematic. Other, problematic plants may not be so well known such as Bradford or Callery Pear, Butterfly Bush, and Rose of Sharon.  Keeping these plants in your yard can cause harm when they move across the street or into the woods next door. Lesson: plant only native species.

There is always a question of “cultivar”.  Tallamy’s research addresses both the harm caused by introduced plants and the vastly understudied topic of “nativars” or cultivars of native plants.  We do know some things. If cultivation has destroyed the pollen and nectar of the native plant as it can, it has rendered it useless to pollinators. If the blossom has been altered to be a double blossom, it is no longer accessible to pollinators.  Pollinators identify flowers by their ultra violet markings, and as far as we know there has been no study on the effect of changing a flower color on the pedal’s ultraviolet markings. We have no understanding of this or the potential harm created. Finally, studies have found that changing a leaf color from green to red in a Ninebark renders the leaf no longer digestible to the insect that requires the green leaf to live.

Since Bringing Nature Home was published, Tallamy’s research has continued.  We are learning more, but not fast enough to protect the insect biomass that makes bird food from plants.  We must stop messing around with nature and stick to native plants. Our ecosystem is in need of ecological gardening practices in every yard.  Will Nature’s Best Hope provide enough science to change gardening practices?  I sure hope so.

Morgan Composting: The Home of Dairy Doo

By Cheryl A. Gross, AEMG

Should you have an opportunity to visit Morgan Composting in Sears, Michigan, I suggest you make time to go.  I visited the site with a group of Plant it Wild members, (also Master Gardeners) on August 23. It was well worth the distance and time required to get there.

Morgan Composting is a family owned business with the fourth generation just reaching the age to operate the pedals of a tractor.  It was born out of a failing dairy farm that struggled to support the family. Incredibly, (after years of risk, hard work, and luck) Morgan Composting happened.  The family has a clear and strong work ethic and sense of fairness from the inputs to the products, the recipes, and the distribution system. There are now 40 employees in 4-5 sites across the state of Michigan.  Their work is science-based and organic. Nothing is wasted.  

The business continues to grow.  DairyDoo is the flagship product.  Organic compost created from dairy cow manure.  The manure is aged and processed in large windrows on the farm.  We had a wagon ride through the property where we saw the piles and piles of inputs in process.  Wood shavings and sawdust are added. Pile heat is maintained at 140 degrees for several weeks to ensure “clean” compost.  Specialized formulas have chicken waste added. Others have mineral elements. All inputs are sourced sustainably.  

In addition to the traditional compost and fertilizer products, Morgan Composting produces liquid fertilizers and worm castings.  We were able to tour the vermi-composting area. It was stunning. Rows and racks of stacked worm bins filled with shredded paper and a food slurry to turn into castings.  After 25 days, the bins are turned out onto the floor. Food is added to the far side to send the worms out of the casting bedding. This is done so the castings can be fed into a screen tumbler to separate the fine castings from the bulkier castings and any remaining worms.  

Besides Dairy Doo, Morgan Composting offers worm castings, seed starter fertilizer, Healthy Garden Fertilizer, Healthy Lawn Fertilizer, and several more specialized products for flowers, vegetables, tomatoes, and more.  In our region you can find Morgan Composting products at Four Season Nursery, Barker Creek Nursery and Pine Hill Nursery. 

Note:  Organic composts and fertilizers improve the soil, thereby providing nutrients for plants.  Synthetic fertilizers feed the plant salt-based chemicals that do nothing to improve soil health, and in reality, degrades the soil health.  While some see organic soil amendments as more costly, in the long run you are saving money by building healthier soil. 

What’s Happening at the Botanic Garden?

It’s been a while since I brought everyone up to date on the exciting things happening at The Botanic Garden.  This past spring, a group of dedicated volunteer gardeners came together to plant a Pollinator Garden under the direction of Laurel Voran, our Horticulturist.  It brings us such joy to see that we are already experiencing butterflies and bees working those flowers.  Next year, this garden should be in full bloom for visitors to enjoy. Last fall, beds were laid out with pathways to follow but recently, a fence was installed by the “possum lodgers” (group of men that do most of the heavy work around the garden) to keep people from cutting through the garden beds. 

Pollinator garden at The Botanic Garden at Historic Barns Park

In addition, this past June, Marty Kermeen began to install 26,000 hand cut pavers to make the Labyrinth.  When completed, this will ultimately be the cornerstone of the healing gardens at the Botanic Garden.  In the beginning, the process took several days to level the stone and lay out the circles. The actual pattern will be done last.  This Labyrinth will measure 4 football fields in length and it is the largest paver labyrinth Marty has ever created. It is fashioned after the famous Chartres labyrinth in France.  Expected completion is sometime this year, at the end of September or beginning of October. 

Marty Kermeen installing pavers at The Botanic Garden at Historic Barns Park

Please plan to visit when you can.  The Botanic Garden is open Monday through Saturday from 9-5 and on Sunday from Noon to 5pm.  Free tours are available–just sign up on the website. Walking tour maps are also available for those who choose to do their own tour.  And . . . don’t forget to visit the fabulous gift shop at the Biederman Visitor Center.