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Garden Plot: Moles, voles, bugs and seeds

January 24, 2020, 4:24 AM

Mike returns to Chantilly next month!

Mike will appear on Saturday and Sunday Feb. 22 and 23 at the long-running Capital Remodel & Garden Show at the Dulles Expo Center in Chantilly. Exact times and details are coming soon, but expect to hear about tomatoes, organic lawn care, compost — and, of course — answers to your toughest garden questions! (Or evasion of said questions, which is more fun …)

Moles a problem? Could it be voles instead?

Sue in Ellicott City has three questions. Here’s the first one:

“Is there a humane way to get rid of moles?”

My weasel word answer here is “maybe.” But first we have to positively ID the pest mammal.

Moles — M O L E S — live under lawns and make raised tunnels that damage the grass, but they don’t eat plants; they only eat meat: earthworms, beetle grubs and cicada larvae.

Voles — V O L E S — make little holes everywhere and feed only on plants — especially tasty spring bulbs like tulips and crocus and the roots of plants like Hosta. In summer, you can often see the ‘lanes’ of tamped-down grass they make as they skitter across lawns in the evening.

Voles are the primary food of owls; and raptor perches — crossbeams placed about six feet off the ground — will often end a vole infestation.

Voles make little holes everywhere and feed only on plants. In summer, you can often see the ‘lanes’ of tamped-down grass they make as they skitter across lawns in the evening. (Getty Images/iStockphoto)

OK — back to moles

Mole repellent products containing castor oil are the first line of defense, Sue. Available in granular and liquid form, they release a nasty smell into the soil that often chases moles (and voles) over to the neighbor’s turf. Look for products with the highest levels of active ingredient (which, again, is castor oil).

Next up are products that eliminate lawn grubs, one of the primary food sources for moles. (Keep reading to learn your natural grub control options below.)

If getting rid of the grubs doesn’t get rid of the moles, your last option is lethal traps that can be difficult for homeowners to use properly; unless you’re really good at this kind of thing, you’re probably better off hiring a professional.

Don’t waste your money on gimmicks or folklore: Little windmills, pinwheels, sonic devices, Juicy Fruit gum and poison gummy worms do not work. Moles only eat meat — they won’t touch gum or gummies.

Outdoor cats also work, but I’m in enough trouble without recommending anything like that.

Gross and greasy grimy grubs

Sue in Ellicott City is battling moles and writes (for her second question):

“How do you get rid of those nasty grubs in the soil?”

Good thinking Sue, as grubs — the larval form of Japanese and other Scarab Beetles — are the number one food source of moles.

There’s nothing you can do right now, but in the spring, you can spread BTG, a new biological control available under the name grubHALT from Gardens Alive. Although it works better in the late summer, BTG should take out a good number of grubs in the Spring.

After the soil warms up, beneficial nematodes step up. These microscopic predators (available via mail order and from the hippest independent garden centers) attack and kill white grubs before they can emerge as flying adult beetles.

And finally, milky spore disease works well when applied in late summer, when young grubs are actively feeding on the roots of your lawn. Unfortunately, this decades-old biological control does not work in the Spring, when grubs are not feeding.

Oh and of course all of the above are nontoxic and grub specific.

Those stink bugs owe you rent!

For her third and final question Sue in Ellicott City writes:

“Why are stink bugs invading my house again?”

They are not, Sue. Any stink bugs you see indoors now came into your home in the fall, when they gather on the South and East facing sides of light-colored homes and look for little nooks and crannies they can use to get inside and hibernate — just like they do in caves in their native Korea.

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They’re waking up now, looking for ways to get out — which is foolish because they would have frozen to death outside last week and wouldn’t do well even now. The same is true of multicolored Asian ladybugs, conifer seed bugs and other “home invading insects.” They find ways to sneak in the Fall and then realize It’s much harder to get out when they wake up.

Just crush any you see with a tissue (not your bare hands; remember their name is STINK bugs) or buy one of those insect trapping bug vacs, like the highly rated one that Hammacher-Schlemmer sells.

Seed catalog of the day!

The new catalog from Gurney’s Seed and Nursery Company contains a plethora of enticing varieties.

Like “Yum Yum” a tri-color mix (red, yellow and orange) of miniature sweet bell peppers that are ready to pick a speedy 55 days after planting: that’s versus 80 days to 100 days for full sized bell peppers! And these little sweeties are seedless!

With peppers, tomatoes and other ‘started indoor’ crops, ‘days to maturity’ means the number of days from when you put a six to eight week old ‘start’ outdoors into warm soil until you get the first ripe fruits. With sweet corn, sting beans and other ‘direct seeded’ crops it’s the number of days from planting the seed to ripeness.

Think your climate is too warm to grow rhubarb? Gurney’s traveled to Australia to find a new heat-tolerant variety they call “Kanra-Rhu,” said to ripen fully red without any of those annoying green or pink areas. They add that they were still harvesting this rhubarb into mid-July in their Ohio test gardens (which I had the pleasure of visiting last season).

How about a mix of heirloom cutting lettuces that contains 500 seeds for less than four bucks? Or “Smooth Criminal” — a hybrid summer squash (like zucchini, but a yellow ‘crookneck’ type) that produces its fruits on a stalk instead of the ground?

BONUS: Order before the 29th and get $25, $50 or even a hundred bucks off! That’s $25 off an order of $50; $50 off an order of a hundred bucks; and $100 off an order of two bills. See it all or request a catalog online.

Weed Beater: Dandelions

Dandelion seeds can remain viable for decades when conditions are not conducive to germination.

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Dandelions Growing

The aggressive growing dandelion has developed a reputation as the most recognized weed invading suburban lawns.

The aggressive growing dandelion has developed a reputation as the most recognized weed invading suburban lawns.

The dandelion (Taraxacum officinale), also known as puffball, lion’s head and monk’s head is a broad-leafed flowering weed commonly found growing in areas with good drainage and direct sunlight. Dandelions were first introduced to North America from Europe, likely arriving with the earliest settlers, who carried them on board their ships for both culinary and medicinal purposes. More recently, this aggressive grower has developed a reputation as the most recognized weed invading suburban lawns. Jagged leaves growing out as much as ten inches and emerging from an anchoring taproot, the bright yellow flowers that sprout from its hollow stems make the dandelion easy to identify, but control of this well-known weed is a challenge familiar to many homeowners throughout the growing season.

Dandelions are a simple perennial and propagate through the spread of seeds. Usually triggered by frost or when daylight hours grow short, the flowers of the dandelion—each head actually a cluster of tiny flowers—dry to become the familiar white “puff ball.” Hundreds of fine hairs each hold a seed that carry readily in the wind, a single plant spreading seeds over hundreds of yards. Seeds germinate easily on or just below the surface of moist soil when temperatures remain consistently over fifty degrees. When conditions are not conducive to germination, dandelion seeds can remain viable for decades and may become active when soil is agitated by tilling or when environmental circumstances become more favorable.

The spread of dandelions can be reduced through regular lawn maintenance. Grass should be mowed regularly and to an appropriate length. Although dandelions that have been mowed down will grow back, destroying developing flowers before they are able to mature into seed distributors prevents the opportunity for new germination. Improving soil conditions through composting can also reduce dandelion growth. Although they will grow in many conditions, dandelions prefer acidic soil and adjusting the pH of acidic soil can inhibit rampant growth.

When mowing a lawn prone to weed issues, forgo bagging grass clippings. Mulched clippings left on the lawn promote grass health and also inhibit the germination of dandelion seeds on the soil surface. Mulches can also be applied to flower beds to discourage weed growth and to smother existing weeds.

Although labor intensive, hand removal of each dandelion ensures it will not return. If the root is left intact, the plant will return, so care must be taken to withdraw each dandelion completely. Water the lawn thoroughly to loosen roots. Using a screwdriver or a forked tool designed for weeding, pry each weed from the soil, making certain to extract the entire root.

If necessary, herbicides may be employed to control an extreme or persistent dandelion infestation. Herbicidal applications are most effective when applied in spring or fall. When using herbicides, do not mow grass for several days before or after treatment and plan to treat when conditions are dry for maximum efficiency. As with all chemical treatments, consult manufacturer documentation regarding proper use and safety concerns.

Marigolds as an Insecticide

21 September, 2017

Marigolds are most useful in repelling or warning away bugs when planted along with vegetables and fruits. This does not work on all bugs, and works best with non-hybridized, older varieties of marigolds, which have a stronger smell. The marigold family has several types; check hardiness and recommended soils before planting. Marigolds of most types work best on soil nematodes.


Marigolds originated in Central America. They are now inhabitants of much of Asia, Europe and the Americas; they have been used in perfumes, dyes, inks, paints, ornamental arrangements, in landscape design, and in religious ceremonies. Along the way, their insect-repellent properties were noted. These plants are sometimes confused with the European-origin calendula, also called marigold, and are even sold as calendula, but do not have the same properties.


Organic gardeners say that marigolds keep the soil free of plant-damaging nematodes, and discourage many insects in the garden. They may, however, attract spider mites and slugs. They also discourage whiteflies from attacking tomatoes when planted in a companion planting. Marigolds also deter beetles.

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Many modern nursery strains of marigolds are de-scented, which will not deter bugs at all. Look for more old-fashioned varieties that are strongly scented. Note that some of the most effective bug-repelling types may have other unpleasant effects. French marigolds are great at repelling nematodes in particular, secreting a substance from their roots that keep them away. However, they shouldn’t be planted near bean plants, as the beans will absorb the substance and bitter taste. Mexican marigold is the strongest-smelling marigold, and keeps away beetles and possibly even rabbits, but also has herbicidal properties toward some plants, including beans and cabbage.


Marigolds repel bugs best when planted in the ground near susceptible plants. Many gardeners add a marigold border to a vegetable garden, or ring their prize tomatoes with marigolds to keep off common vegetable and fruit pests. This is no guarantee, but they can help reduce bugs eating your food if you have the room to plant the strong-smelling marigolds. The closest thing to an insecticide wash you can obtain from marigolds is a bitter tea that, applied to lawns, patios or other plants, can help keep away crawling and flying bugs temporarily.


It can be tough to sort out the varying opinions on using marigolds as an insect repellent. Many garden professionals will tell you they don’t work, while many home gardeners swear by them. Don’t expect that planting marigolds gets rid of all the bugs in your garden, and realize there are some bugs, like mosquitoes, that marigolds will have no effect on at all. It is also unlikely that a treatment with marigold parts in it will actually kill any bugs; the best it will do is repel them from the applied area.

Controlling Aphids, Slugs and Snails

Sustainable ways to keep damaging pests away.

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Sweet Potato Vine with Aphids

Aphids appear in great concentrations in early spring, when plants are pushing new growth. These sucking insects love to feast on tender, juicy new growth.

Photo by: Julie Martens Forney

Julie Martens Forney

Aphids appear in great concentrations in early spring, when plants are pushing new growth. These sucking insects love to feast on tender, juicy new growth.

Attacked by aphids? Stricken with snails? Sometimes the smallest pests can do the most damage in your garden. But you don’t have to resort to chemical-based pesticides to discourage — or downright evict — bugs, slugs and other small garden enemies. Here are some tried-and-true tactics for keeping them away, naturally:

Shagbark Hickory Trees

A species indigenous to North America, shagbark hickory trees are widespread in the Eastern U.S. in zones 4 to 8. They are related to the pecan, another native American nut bearer. Although they can reach a height of 130 feet in some portions of their range, these popular nut trees often reach only about half that size. They grow in full to partial sun.


Shagbark hickory trees are slow growers if left to their own devices, so you will need to cheat if you wish to plant one and harvest home-grown nuts from it sometime soon. It would just take too long to enjoy a harvest if you tried raising seedlings from the wild.

Nurseries that sell commercial cultivars do the cheating for you by employing grafting techniques that produce superior specimens. These cultivars can yield a harvest in as little as two to three years.

Examples of cultivars are ‘Grainger,’ ‘Abundance,’ and ‘Yoder.’ Since their long taproots make the trees difficult to transplant, make sure the nursery from which you buy plants has a sensible guarantee policy.

Shagbark hickories are not grown exclusively for their nuts. In fact, one could easily rank nut production only third among the reasons why homeowners might consider planting them, as explained below.


Shagbark hickories are deciduous and provide excellent fall foliage color. In autumn, their leaves turn a golden color—richer than the yellows displayed by the maples.

«Shagbark» hickory trees derive their picturesque name from the interesting peeling bark they bear. This unusual bark juts out from one or both ends, curling outward. Even when the leaves are long gone from the deciduous trees in winter, this feature provides landscape interest.

The fragrant nut the trees bear is said to be the tastiest of any of the hickory nut trees.

Growing Tips

The scientific name of shagbark hickory nut trees is Carya ovata, which translates literally as «the oval nut.» Meanwhile, the word «hickory» comes from the Algonquin, «pawcohiccora.» The nuts were an important food source for the Algonquins.

Here are some tips for growing shagbark hickory trees:

  • Plant in spring.
  • Grow them in well-drained soil.
  • Plant so that the root collar rests just below ground level.
  • Fill the hole back in with topsoil, tamping it down as you proceed.
  • Water after installation.
  • Prune to promote growth
  • Suppress all weed growth within a yard or so of your nut tree by mulching.

Pests and Diseases

Like most hickory trees, shagbark hickory nut trees are susceptible to canker, a wood-rotting fungus that will kill the tree. Keeping trees well-watered and scraping off discolored wood may help slow the spread of canker.

Shagbarks also are vulnerable to anthracnose, which causes brown spots on its leaves. While it may lead to leaf loss, anthracnose isn’t considered a threat to a tree’s health.

Among the insects that plague the shagbark hickory are aphids and the aptly-named hickory bark beetle. Keeping trees well-watered is one way to avoid insect pests, but spraying with an insecticide (which is labeled as safe for the tree) is usually the only way to eradicate the bugs completely.

Harvesting Hickory Nuts

When we speak of the fruit (nut) from shagbark hickory nut trees, we are really dealing with three parts:

  • The husk
  • The hard outer shell under the husk
  • The meat of the nut within the hard outer shell

Refrigerate or freeze the nut meat after you have removed it from the shells.

Do not try cracking the husk prematurely unless you are a glutton for hard work. Rather, wait for ripening in autumn.

Ripening begins in September and October. The green, leathery husk eventually turns brown and becomes more brittle. In fact, sometimes, when the nuts fall to the ground, the husks split open into four segments, allowing access to the nut within. Even then, you have still got the hard outer nutshell to crack.

For this reason, some harvesters just wait until late autumn for all the nuts to fall. Just be aware: Rodents and other pests are fond of shagbark hickory nuts and may get to them before you do. Squirrels, raccoons, chipmunks, and mice are among the critters who like these nuts.

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Shagbark Hickory Wood

The wood of shagbark hickory nut trees is very hard, and it is used to make ax handles, baseball bats, and other products that demand tough lumber. The wood also makes for excellent firewood.

When burned, it gives off a fragrant smoke, which is the reason for the popularity of hickory in the meat-curing process. More importantly, for homeowners, shagbark hickory nut trees attract wildlife and not just the pests mentioned above. Some of the larger wild birds eat shagbark hickory nuts, including turkeys.

MSU Extension

Whether it’s your vegetable garden, flowers or woody ornamentals, when foliage, flowers or entire plants are missing, the big question is “Who did this?”

If a gardener isn’t sure what pest is causing foliage, flowers or entire plants to go missing, time and effort can go into the wrong solution and the plant material keeps disappearing. The two divisions of pests for this article are vertebrates, such as deer, rabbits, woodchucks and chipmunks, and some kind of insect. It is important to realize that animal repellants will not repel insects. Insecticides almost never repel animals. Using the correct product is important. Try to figure out who your target is. Having a ten-power hand lens or magnifying glass can help you see more of what is really going on.

When looking at plant damage, think of the size of the animal. It is impossible for an animal to eat small holes in leaves or to just strip tissue away. An insect cannot consume entire leaves, veins and midrib included, but they can feed on plants at all heights. Animal damage above 3 feet high is often deer, but woodchucks can climb to eat leaves or fruit. Damage low to the ground can be any animal, and damage from insects and animals can occur overnight or during the day. These are the kinds of answers that Michigan State University Extension horticulture educators and Master Gardener hotline staffs give every day. Here is a quick look at some common problems.


  • Small holes in the middle of leaves or edges chewed, and edges of hole are leaf-colored: Insects
  • Upper and lower leaf tissue removed, leaving just veins: Insects
  • Tan leaf with top and bottom intact, but no tissue in between top and bottom: Insect
  • Missing entire leaves with or without petiole, or connecting stem: Animal
  • Petiole of tree leaf cut or damaged and found on the ground, yet leaf is healthy: Insect
  • Missing parts of leaves, nothing left like leaf mid-vein: Animal
  • Hosta leaves removed to their stems: Usually deer

Leaf skeletonizing characteristic of bean beetle feeding. Photo credit: David Cappaert, MSU ,


  • Tips of spruce new growth is cut off and on the ground in the spring: Squirrels
  • Ends of branches have needles partially removed or shoot is cut and on the ground: Deer

Entire plant

  • Small transplants or seedling cut off at almost ground level: Cutworms
  • Small, tender plants clipped off at ground level and missing: Animal
  • Newly planted bulbs dug up and pushed aside: Raccoon or skunk


  • Missing entire flower and possibly stem: Animal
  • Flower bud and stem gone: Animal
  • Small, round, brown or black spots that look thin and dried out on mints and chrysanthemums: Insect
  • Small, ragged or rounded holes in petals: Insect

Garden vegetables

  • Tomatoes close to the ground have holes poked into them: Birds
  • Vegetables or fruit touching the ground are chewed into on bottom side: Slugs
  • Young green bean plants appear to be mowed down: Woodchucks
  • Squash and pumpkin leaves with gray, wilted areas and holes late in summer: Squash bugs

Animal damage can be handled two ways: a fence or netting can be put up to keep the animal or bird out, or a repellant can be used to discourage animal feeding, but repellants do not work on birds. There are many more repellants created for ornamental plants than food plants. Be sure to read the label.

For insect problems, insecticidal soap will work on soft-bodied insects like aphids, spider mites and caterpillars, but not on hard-shelled beetles. Call the MSU Extension Garden Hotline at 888-678-3464 for help with your insect or animal problems.

This article was published by Michigan State University Extension. For more information, visit To have a digest of information delivered straight to your email inbox, visit To contact an expert in your area, visit, or call 888-MSUE4MI (888-678-3464).

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Grow Guide: Ladybug Home Invasion

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Q: Help! I am finding ladybugs in my house by the dozens. Why are they coming in and what can I do about them?


First off, calm down because ladybugs (also known as lady beetles) will not harm your house. They eat aphids, not fabric or wood. Besides, if you upset them they can quickly excrete a protective smelly yellowish fluid that can stain. Some folks just hate insect infestations. But the beetles are relatively harmless, though some, if given a chance, may lightly nibble on your skin. Have I mentioned that they are not very bright?

They are in your house because in nature they hibernate over the winter in masses, usually in protected places like cracks in rocks, tree trunks and other warm places, including buildings. When one finds a suitable spot in the fall, it produces a pheromone that attracts others, so it is common to find dozens if not hundreds at a time. And often a few misguided beetles get confused and come into rooms through electrical outlets and other openings in walls.

Go With The Flow

Unfortunately, there are no really good ways to handle lady beetle infestations. Once they get in, they are nearly impossible to get rid of until spring when they naturally head back outdoors. Trying to kill those that are hibernating in wall cavities is rarely effective.

Sweep them out, being mindful of the yellow secretion they can leave on walls. Use a vacuum cleaner on large infestations. If you want to release them outdoors, put a piece of paper towel between the vacuum hose and the collection bag as a trap.

The best approach is to prevent them from coming in next fall by sealing cracks around windows, doors and roof soffits. But this may be impossible in the long run.

And by the way, “ladybug houses» sold in garden supply catalogs usually don’t do a very good job at keeping the beetles out of your home.

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