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Extension Master Gardeners - Renville County

This is our last issue for 2020

It is time for the newsletter to end for 2020, just like our gardens. We will be back February 2021 to start anew. We Thank You for reading our newsletter and hope you enjoyed reading through the issues! See you in 2021!!!

A newsletter by the Renville County Master Inside this Issue: Gardeners containing USDA Zone 4 appropriate information October Garden Tips – Page 2 Volume 142 October 2020 Become a Master Gardener – Page 2

Cacti - Page 2 Meet the Renville County Wildflower of the Month: Milkweed – Page 3 Master Gardeners Louise Schweiss Betsy Hennen – Fall Turf Problem -Page 4 Anderson–Fairfax; Olivia; Beetles on your Asparagus – Page 7 Joy Clobes - Fairfax Jan Howell – Olivia; Teide Erickson - Pam McColley - Orange Beetles killing my flowers, or are they? - Franklin; Winthrop Page-9 Sandy Feldman – Linda McGraw – Renville, Buffalo Lake; Storing tender bulbs - 10 Cathi Fesenmaier – Beth O'Keefe – What’s Happening – Page 11 Olivia; Morton; Erin Grams – Hector; Marie O'Keefe – . Susan Haubrich – Morton Danube; Barbara Stone- “My garden is my most beautiful masterpiece” Renville Claude Monet

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This Photo by Unknown Author 1

October Garden Tips • October marks the peak of fall bulb planting. Soil preparation is the important first step. Work the soil when it is dry or only slightly moist. Bulbs need well- drained soil for best results and to prevent rotting. Planting earlier than October increases the risk of bulbs sprouting prematurely during a warm fall. Keep planting bulbs until the ground freezes. • Keep frost protection nearby to keep your annuals going. Cover plants in late afternoon when there is a danger of frost. Remove the coverings when temperatures warm. • Harvest squashes and pumpkins before the first frosts. They will quickly turn mushy if left outside. They should be harvested when they have a bright color and a thick, hard skin. • Keep watering trees, shrubs and evergreens until the ground is frozen. Trees and shrubs need sufficient water to survive our dry winters. • Fall cleanup is an important key to pest control. Remove diseased or pest-infected foliage. This reduces the source of insects and disease for next season. • Tune Up Your Tools - Clean dirt off tools and sharpen blades before storing them for the winter. Push tools into a bucket of sand treated with old motor oil to help protect from rust. Source: “Month-By-Month Gardening Minnesota & Wisconsin” by Melinda Myers

If you or you know someone who would love to join us as Master Gardeners, please contact the http://z.umn.edu/mg2021app and one of our Master Gardeners will contact you. And NO, you do not have to be an expert already, none of us were or are at the present time. We just have places to go to get the information people need. So, if you just garden via pots, or have a small plot garden, or just love houseplants, you can become a Master Gardener. Because of all of us that belong have different interest and different knowledge levels. But we have one thing in common, we love plants. Anyone can do this; our group will help you the first year to get you what you need to get your official Master Gardener certificate. Application deadline is October 1st. All you need to do now is Call US! Thank You! Renville County Master Gardeners

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Cacti By: Joy Clobes, Renville County Master Gardener

Cacti belong to a group of plants called succulents. Cacti have round cushion like areas called areoles which are where spines develop. Like the plants we call succulents cacti can store water in their fleshy leaves and stems. They can survive hot arid environments with limited rainfall.

When looking for a cactus to purchase try to find one that has been properly cared for. Look for potting soil that is dry to the touch. A cactus with soggy soil may have been overwatered and could develop root rot. Also look for a cactus that is growing straight- not leggy or leaning toward light. Make sure the plant has a healthy color and try to avoid those that have been painted or have flowers glued on.

When you purchase a cactus, it will probably come in a plastic pot. Plastic is ok for a cactus, but it is not porous, so plants could become waterlogged easier. Terra-cotta pots are heavier than plastic and will be more stable for the tall or top-heavy plants. Terra-cotta is also porous which helps improve drainage.

Most cacti need a bright sunny location, a south facing is ideal. If cacti are moved outside for the summer put them where they can have some shade during the hottest part of the day.

Cacti do not like big temperature changes. Keep them away from very cold windows in the winter. Cacti grow in the spring and summer and like temperatures of 80-85 degrees. In the winter when resting they like cool nighttime temperatures but not lower than 50 degrees.

Water at the proper time is probably the most important part of caring for cacti. They want frequent watering during their growth period from April until early September. In September and October gradually reduce watering. During cacti winter rest period from early November until the end of February cacti needs no water. Gradually increase watering in March. Watering cacti during their rest period will lead to rotten dead cacti. Winter flowering cacti like Christmas Cactus will need water every two weeks or so until they finish flowering.

Cacti, like all plants need fertilizer. Add a balanced plant fertilizer to water and fertilize two or three times during the active growth period.

Since cacti are slow growers, they will need repotting every two to four years. The best time to repot cacti is at the end of the winter rest period, this would be in March or April. Cacti and succulents prefer a snug fit so choose a pot only slightly larger than the present one. You can purchase a ready-made cacti and succulent mix or make your own. Gently remove the cactus from its pot, gently loosen the roots and place in a new container no deeper than it was in its old pot. Wait a few weeks after repotting to resume watering your cactus.

About four years ago I purchased my first cacti. They are the perfect houseplants for me, I am not particularly good at watering and cacti do not like water in winter. I like to move my plants outside for the summer and let nature water them.

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Fall turf grass problems? Grubs might be the culprit If you are noticing ugly, dead patches in your lawn, you might have an active population of white grubs. White grubs can cause serious damage to turfgrass. Their feeding injures plant roots, causing the turf to wilt and die.

This Photo by Unknown Author is Symptoms of grub damage include: • Patchylicensed areas under of CCwilting BY-ND discolored or stressed turf that does not respond to irrigation. • Large irregular patches of dead turf that can be rolled back like a loose carpet. • Raccoons, skunks, and crows tearing up the lawn (looking for grubs to eat).

Lawn damage caused by May-June beetle white grubs

Japanese beetle grub damage White grubs, what are they? White grubs are the immature phase, or larvae, of beetles in the scarab family. In Minnesota, white grubs are typically the larvae of May-June beetles and Japanese beetles. Like all beetles, white grubs undergo complete metamorphosis. Adult beetles lay their eggs in the ground, where the eggs hatch and the beetle larvae live. The beetles progress through the egg stage, several immature (larval) stages, and a non-feeding intermediate (pupa) stage to the adult stage.

The bodies of white grubs grow considerably throughout their life cycle and they move within the soil. White grubs cannot tolerate freezing temperatures; when temperatures cool in the fall, larvae move lower in the soil, below the normal frost line, to survive winter. When the weather warms, they move up to feed on roots.

Different species of white grubs look like one another but can be distinguished by the arrangement of hairs and bristles on the underside of their abdomen at the tip called a raster pattern. Raster patterns are challenging to see and recognize; an expert should identify any pest grubs. Management will differ based on what species of white grub is present in your yard because they have different timing for their life cycles, which means different timing for management.

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May-June beetle grub raster pattern

Japanese beetle grub raster pattern

May-June beetles

May-June beetle white grub May-June beetles have a three-year life cycle. The best time to treat them is during their second year, although damage to turf is usually not noticed then.

Year 1 • Adult beetles emerge in the spring or early summer, in May or June, and lay eggs in the soil. • Larvae hatch the same summer. • During the first summer, the larvae feed and grow from the first immature stage to the second. • Typically, this first year of feeding does not cause noticeable injury

Year 2 • The following spring, larvae move upward to feed on roots within the first few inches of soil. • During this second year, the larvae mature into their third larval stage by mid-summer. • As temperatures fall, the grubs again move lower in the soil profile. • Second-year damage is more severe than the first year.

Year 3 • In the third spring, the grubs again move up toward the soil surface to feed until fall. • The mature larvae pupate, and then adult beetles emerge from the soil the following spring. • May-June beetle grubs are typically in the same stage in each area. Therefore, we commonly see turf damage every three years, when they are in the third year of their life cycle. • Because they are large and about to turn into adult beetles, it is ineffective to treat the grubs at this point.

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Japanese beetles

Japanese beetle grub

Japanese beetles have a one-year (annual) life cycle. There are two types of treatments: preventive and curative. Preventive treatments are the most effective and are applied in late June and early July as eggs are first being laid. Once grubs are present, late July to September, they can still be treated but management is less effective. • Grubs move up near the soil surface in the spring to finish feeding and then develop into adult beetles. • In Minnesota, adult Japanese beetles begin emerging from the ground in late June or early July. • The adults feed on plants and mate throughout most of the summer months. • Following mating, females lay their eggs in the soil several different times throughout July an d August. • The eggs hatch in about two weeks and the grubs go through three larval stages during the summer, which is why we may notice turf damage in late summer or early fall. • Like May/June beetle larvae, Japanese beetle grubs move down in the soil as the weather cools in the fall.

Treating white grubs in the yard The best time to treat for white grubs is early in their life cycle when the larvae are small, or prior to eggs being laid in the soil. Unfortunately, their presence often goes undetected at that time. Treatment for white grubs in late summer is problematic. By September, white grubs are fully-grown and are harder to kill. If your white grub issue is May/June beetles, it is most effective to treat them early during their second summer. Severe damage to turf may have already occurred by September. From Mid-August-October, the following recommendations apply: • Repair damage through seeding or sodding. • If loose sod is still green, keep it well watered to encourage root growth. Give your lawn its best chance by following these steps: • Select turfgrass that is well adapted for your site. • Promote a healthy lawn through: o Proper mowing. o Fertilization. o Irrigation. o Thatch management. o Weed management. Healthy turf can tolerate or quickly recover from most insect feeding and serves as the foundation of “integrated pest management” (IPM). Knowing what type of grub is present in your yard as well as the life-stage of the grubs are useful bits of information as you assess your management options. BY: Robin Trott, Extension educator, Douglas County and Claire LaCanne, Extension educator, Rice and Steele Counties Reviewed by Jeffrey Hahn, Extension Entomologist

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Beetles on Your Asparagus: Why You Should Be Concerned

Figure 1. A) Common asparagus beetle adult. B) Twelve- spotted asparagus beetle adult. Courtesy: Adam Varenhorst. When thinking of asparagus pests, we normally worry about early season feeding on the developing spears. However, late summer and fall scouting is important to get ahead of some of the spring insect problems. Two of the insects that we recommend scouting for are the common asparagus beetle (Figure 1-A) and the twelve-spotted asparagus beetle (Figure 1-B). Although asparagus plants are not producing spears at this time, they are collecting nutrients that will be used to grow spears during the next season. In addition, both of these beetles overwinter as adults near gardens or even in the hollowed stems of older asparagus plants. This means that scouting and managing adults now could mean fewer to manage next year. In addition, both species are capable of having multiple generations per year, so management can greatly reduce population increases. Beetle Identification Figure 2. Common asparagus beetle adult. Courtesy: Adam Varenhorst. COMMON ASPARAGUS BEETLE Common asparagus beetles have a black head and legs, an orange thorax with two black spots, and orange and black hardened forewings (elytra). Each elytron has three cream colored spots on it (Figure 2). However, the size and shape of the cream-colored spots and the two black spots on the thorax are highly variable.

These beetles have black antennae. The common asparagus beetles are approximately ¼ of an inch long and oval shaped. The adults emerge in early spring and are active until the first hard frost.

Figure 3. A) Common asparagus beetle larva. Courtesy: Clemson University, USDA Cooperative Extension Slide Series, Bugwood.org. B) Common asparagus beetle eggs. Courtesy: Ward Upham, Kansas State University, Bugwood.org. Larvae The common asparagus beetle larvae have light gray to cream colored bodies and black heads and legs (Figure 3-A).

These larvae will feed on the ferns of the asparagus plants for approximately two weeks before dropping to the soil to pupate.

Eggs The eggs of the common asparagus beetles are dark brown and cylindrical shaped (Figure 3-B).

The eggs will be placed on the ferns in rows with a space between each egg. 7

Figure 4. Twelve-spotted asparagus beetle adult. Courtesy: Adam Varenhorst. TWELVE-SPOTTED ASPARAGUS BEETLE The twelve-spotted asparagus beetle (also referred to as the spotted asparagus beetle) has an orange head, thorax, and abdomen. The elytra are covered with a total of 12 black spots, hence its name (Figure 4).

The beetles have black antennae and orange legs that have black coloration around the joints. The adults are approximately ¼ of an inch long. These adults emerge in mid-May and can be observed through the fall.

Figure 5. Twelve-spotted asparagus beetle larva. Courtesy: Whitney Cranshaw, Colorado State University, Bugwood.org. Larvae The twelve-spotted asparagus beetle larvae have light gray to cream colored bodies with orange heads and black legs (Figure 5).

The twelve-spotted asparagus beetle larvae feed on the asparagus ferns’ berries.

Eggs Twelve-spotted asparagus beetle eggs are green in color and laid on the ferns. Injury and Management Figure 6. Common asparagus beetle on a curved asparagus spear. Courtesy: Bob Hammon, Colorado State University, Bugwood.org. PLANT INJURY When either beetle feeds on the asparagus spears in the spring, the spears will become brown and will bend over into a shepherd’s hook (Figure 6).

Once the ferns appear, larvae and adults of both the common asparagus beetle and the twelve-spotted asparagus beetle will feed on the leaves and will weaken the plant (Figure 7).

The twelve-spotted asparagus beetle larvae also feed on the berries but feeding has little impact on the plant’s health.

Figure 7. Asparagus fern with defoliation injury from beetle feeding. Courtesy: Whitney Cranshaw, Colorado State University, Bugwood.org. MANAGEMENT The best management strategy for asparagus beetles is to scout the asparagus both in the spring and throughout the growing season and remove the observed beetles and larvae by hand and destroy them. It is important to scout for these pests later in the afternoon as that is when they are most active. If the eggs are observed on the spears or the ferns remove them and destroy them. There are also parasitoid wasps that attack the larvae of the beetles, which can reduce the 8 populations of additional generations. Other natural enemies such as ladybug larvae will also eat the asparagus beetle eggs and larvae.

For large gardens, or when large populations are present, insecticides can be used to reduce the populations. The threshold is when 10% of plants have one adult of either species present or 50 to 75% of plants have larvae present. Before applying an insecticide product, read the label and do not harvest before the listed pre-harvest interval period has expired.

An important fall management strategy is to clean your garden. Do not use grass clippings, mulch or leaves around asparagus plants as the adults can use these materials to protect them for overwintering.

Adam Varenhorst Assistant Professor & SDSU Extension Field Crop Entomologist Additional Authors: Amanda Bachmann,Philip Rozeboom,Patrick Wagner

Orange Beetles Are Killing My Flowers, or Are They?

Many gardens are being invaded by orange beetles that have a strong preference for flowering plants. Rest assured, these are soldier beetles and they are not feeding on the flowers! Instead, they are predators and pollinators. Figure 1. Soldier beetle foraging on a flower. Courtesy: Adam Varenhorst Soldier Beetle Identification Adult soldier beetles vary in color depending on the species. The most common species on flowers in South Dakota is the goldenrod soldier beetle, which is orange in color with two black spots near the end of the body on their cloth like forewings (Figure 1). The adults also have a black spot present on their thorax (segment directly behind the head). These beetles are elongate and are approximately ½ of an inch long. The soldier beetle larvae are worm-like and have a rippled appearance. These larvae are typically a brown or gray color and are covered in small hairs. The larvae can be up to ¾ of an inch long. However, the larvae are not typically observed. Why are these insects beneficial? Both the adults and larvae of soldier beetles are predators that feed on other insects. Often, their prey are also common pests, including soft bodied insects such as caterpillars and aphids. The adults will wait on a plant for prey. During this time, they may feed on the nectar and pollen of the plant. However, they don’t damage the plant while doing this and they don’t feed on the flower petals. There is no need to manage soldier beetles – instead, enjoy observing them and the beneficial service they provide.

BY: Adam Varenhorst Assistant Professor & SDSU Extension Field Crop Entomologist Additional Authors: Amanda Bachmann,Patrick Wagner,Philip Rozeboom

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Storing Tender Bulbs Digging bulbs

• Dig up tender bulbs from soil after the foliage dries up or is killed by frost. • An exception to this is Peruvian daffodil (ismene or Hymenocallis), which should be dug before frost damages the plant. • Loosen roots gently with a garden fork or spade by digging several inches away from the base of the plants. This will prevent cutting off the roots. • With dahlias or other large plants, loosen the soil on all sides of the plant before lifting the clump of roots and soil. • In all cases, avoid cutting, breaking or "skinning" the fleshy structure as diseases can easily contaminate plants cuts and bruises, causing rotting and death.

Cleaning bulbs

• Some plants are best washed gently with a hose (e.g. dahlias). • Put hardware cloth (or a large mesh screen) across the top of a large garbage can and set a clump of dahlias or cannas on the hardware cloth or screen and wash the soil into the garbage can. o This eliminates mess and the soil and water can be returned to the garden, so it is not completely wasted. • You also can reuse the soil by putting it on the compost pile. • Gladiolus corms are best left unwashed and allowed to dry. After drying, the soil may be gently removed.

Curing bulbs

• For most species (dahlias, cannas, calla, caladium), the curing or drying period should be between 1 to 3 days, depending on temperature. • Curing should be done in a room or area away from direct sunlight or drying winds. • Long-term curing for gladiolus, tigridia and oxalis should be approximately 3 weeks. • For gladiolus, the old corm and cormels should be removed. • Drying and curing temperatures should be 60 - 70° in a dry, well-ventilated area.

Pest management

• Before storing corms, inspect for insects or diseases. • Dust with an insecticide-fungicide mixture labeled for the specific plant.

Storing bulbs

• Store tender bulbs in cool (an average of 40° F), dry conditions. • Dig 6 to 8 weeks after bloom, when the leaves turn yellow. • Exceptions to the average temperature for storing tender bulbs are: o Peruvian daffodil (Hymenocallis narcissifoli) - store at 60 - 65° F. 10

o Tuberose (Polianthes tuberosa) - store at 55 - 65° F. • Label stored plant material carefully. o In case of gladiolus and similar plants, place the corm in a small paper bag which has been properly labeled.

Larger materials, like dahlias or canna can be handled in several ways.

• Write directly on the fleshy root with a permanent felt marking pen. • If this is done on large clumps the cultivar name should be written on several roots rather than on just one, because in storage a root may break off of the main clump. • Wood and wire tree labels also work very well for labeling. • Cultivar name or other important identifying characteristics should be written on the label and also recorded in a notebook or in some other way.

Remember to periodically check stored bulbs, tubers and roots during the storage season. Remove any damaged or rotting material.

In cases where tuberous roots like dahlias have some rot, cut back until you reach clean white, fleshy tissue again. These structures may need attention and care even during their dormant period. Mary H. Meyer, Extension horticulturist

What’s Happening

In our area ; At the Minnesota Landscape Arboretum: If you are interested in more information, contact a Master Gardener or email the Renville County Extension For more information on what’s happening at the For more information on what’s happening at the Office at [email protected] Arboretum, please visit http://arboretum.umn.edu/gardeningclasses.aspx Need to contact us? Call the Renville County Extension Office at 320-523-3713, or e-mail us at [email protected] Monday – Thursday 8 a.m. to 4:30 p.m.

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