Master Gardener

September To-do Lists Nudge Gardeners

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Winter squash is ready for harvest now.  Photo:  Home & Garden Information Center

I know. I know. You’re tired after a long season of gardening. Especially with all that heat we had. But there are still a few things to tick off your fall to-do list.

Have you planted your garlic yet? Now’s the time. Nestle cloves into the soil through the end of October for harvest next July. Get tips here: Growing Garlic in a Home Garden.

Even if your vegetable garden is looking ragged, keep harvesting. My cucumbers finally gave up the ghost, but I’m still getting enough tomatoes and basil for Caprese salads.

I just harvested butternut squash, too. The rind was finally hard enough not to dent with my fingernail, so they were ready. I’ll cure them for a week in a warmer room, then store them in my cooler basement. Learn more: Growing Winter Squash in a Home Garden.

And yes, I’ve started to remove spent and scruffy vegetable plants, clearing the bed of fallen fruits, leaves, and stems. And no, it’s not just because I’m a neatnik.

Soilborne diseases are the most common cause of vegetable problems. Those plant bits can harbor fungal spores which can reinfect plants year after year. 

So I’m ruthless in removing plant debris. I compost healthy plant parts, but bag and trash anything that has had disease issues.

After cleanup, I add compost. It feeds the soil, adds organic matter, improves drainage, holds nutrients, attracts earthworms, and suppresses disease. What’s not to love?

Buy compost or make your own. Mix leaves, grass clippings, kitchen scraps, and other organic materials into a pile. Stir it now and then, water it when it’s dry, and let it cook down into the best soil food ever. Learn: How to Make Compost at Home.

a gardener working on a compost bin
Master Gardener Gary Stallings turns compost in a teaching garden. Photo:  Shanon Wolf

This year I’ll top off my vegetable beds with an inch or two of compost to improve the soil and act as a winter mulch and weed blocker.  

Yes, weeds grow in winter. Winter annuals such as chickweed, henbit, and speedwell love bare soil, germinating in late summer and fall and returning vigorously in spring.

Don’t let them get a toehold. Cover bare soil with compost, mulch, or a cover crop.

Cover crops are all the rage, a classic farming technique that’s discovered new life in gardening circles. Sown from seed, they block weeds and slow erosion.

Best of all, cover crops feed and improve soil. Their deep roots mine nutrients and their leaves, stems and roots break down to add organic matter when they are turned into the soil in spring.

Many cover crops can be planted in the fall. Which is best for your garden? Find out here: Cover Crops for Gardens.

crimson clover
Crimson clover is an attractive cover crop that improves soil. Photo:  Home & Garden Information Center

After I tend to my vegetable beds, I dig and divide perennials. Most perennials should be divided every 3 years. Just lift a clump, cut it into sections, and transplant and water well.

Resist the urge to cut back your perennials in the fall. They provide crucial overwintering sites for pollinators and food for birds and other wildlife. Only cut back plants that had serious disease or insect issues.

Fall is a time to put a tidy bow on the gardening season, to lay to rest your beds after you squeeze out the last harvests. Feel the change in the air, breathe deeply, and enjoy the delicious ache of a job well done.

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.

This article was previously published by Herald-Mail Media. Read more by Annette.

  

What to Know Before Applying Pesticides in Your Garden

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a man inside of a hardware store reading a pesticide label
Before using a pesticide, read the label. Photo: Oregon Department of Agriculture, CC.

You have a pest problem in your garden – maybe it is hungry insects feeding on your vegetables, or stubborn weeds taking over your flower patch, or fungal diseases killing your lawn. You might consider using pesticides (which include insecticides, herbicides, and fungicides), especially if the problem seems widespread or severe. How do you choose the right pesticides and apply them correctly to support a healthy and thriving garden? How do you ensure your food plants remain safe for consumption and adverse impacts on beneficial species and soil health remain minimal?

Choosing the right pesticide

Home gardeners can generally choose between two types of pesticides: general use pesticides and minimum risk pesticides. Both pesticide types come with labels that explain how to safely handle, use, and dispose of the products. The labels of general use pesticides are reviewed by the Environmental Protection Agency (EPA) and will have an EPA registration number (highlighted by the blue rectangle on Figure 1), typically on the back panel. The labels of minimum risk pesticides are less extensive and are not reviewed by the EPA as they pose minimal risks to humans and the environment. Since these labels lack an EPA registration number, you can verify the product’s authenticity by contacting the Maryland Department of Agriculture’s State Chemist Section (410-841-2721). Alternatively, you can check out this list of approved minimum risk pesticide substances (PDF).

an example of a pesticide label for Houseplant and Garden Insect Killer
Figure 1: First representative label (back panel)

Regardless of the pesticide type, it is important to select a pesticide that has a narrow activity range. If your pest is an insect, you would ideally want a pesticide that targets insects. It would be even better if you could narrow down your insect pest – is it a caterpillar, beetle, or aphid? Some pesticides are more effective against certain pest insects (for example, see the product in Figure 2) and are therefore less likely to harm non-target insects. If you are unable to identify your pest, you can submit questions and photos to the University of Maryland’s Ask Extension service. Ask Extension will help identify the pest and recommend a course of action. 

Another important criterion for pesticide selection is human safety, which can be determined from the signal words on the front panel of the label (see the purple rectangle highlighted in Figure 2). Danger signifies high toxicity, warning signifies moderate toxicity, and caution signifies low toxicity. A pesticide that is virtually non-toxic may have no signal word. Ease of use and application frequency can also help make your choice, as it may not always be feasible to measure and mix or frequently apply the product. This information is typically part of the section on directions for use, often found by peeling open the entire label (see the black rectangle highlighted in Figure 1).

a sample label from a biological insecticide called Monterey B.t. - the caution word on the label is highlighted
Figure 2: Second representative label (front panel)

What else to look for on the pesticide label

Labels also include the following information on the front panel (see Figure 2): product brand name, ingredients, and the statement “Keep out of reach of children”. Other information found typically on the back panel (see Figure 1, which includes the label peel) are precautionary and other hazard statements, first aid, and storage and disposal sections. It is important to read all these sections properly, including the entirety of the directions for use, prior to the use of the pesticide. 

  • The precautionary statement typically includes personal protective equipment that needs to be worn during pesticide applications (for example, full-length clothes, gloves, and eye protection) and informs the period of time during which one must not enter or come into contact with the treated area. The signal words are repeated in this section. 
  • Hazard statements warn of potential hazards to the environment, including soil, water, air, wildlife, and nontarget plants. An example warning statement is “This product is highly toxic to bees”. This section may also include possible fire, chemical, or explosion hazards posed by the product.
  • First aid section recommends steps to be taken in case of accidental exposure or poisoning. The instructions vary in accordance with the route of pesticide exposure (swallowing, inhaling, contact, and eye), and include statements like “sip a glass of water if able to swallow”, and “take off contaminated clothing and rinse skin with water for 15-20 minutes”. Often, there is information on who to contact in case of a medical emergency. If you need to visit an emergency health provider, remember to take the pesticide label with you. 
  • Storage and disposal section provides information on how to store the product (for example, “store in the original container in a cool and dry place” and “protect from freezing”) and dispose of it (for example, “triple rinse the empty container” or “place the empty container in the trash”). The Maryland Department of Agriculture has often had an annual program where one could recycle an empty pesticide container for free. If you would like to dispose of unused pesticides, follow the instructions in the disposal section. Never dispose of pesticides down any indoor or outdoor drain. Many Maryland counties offer options to safely recycle or dispose of household hazardous waste, including lawn and garden pesticides. Current or retired farmers and producers can also avail of a free pesticide disposal program offered by the Maryland Department of Agriculture.
  • Directions of use section instructs how to properly use the product. This section typically includes a description of intended uses, mixing and application methods, use rates, and sites where the product may be used. It can also include application restrictions – this consists of statements like “do not apply if rain is predicted within the next 48 hours” or “do not apply when bees are actively foraging”. In many labels, application restrictions are also found within the hazard statements section. 

Why is it important to follow the label?

A pesticide is any substance that prevents, destroys, repels, or mitigates pests. Thus, by nature, pesticides negatively impact living organisms. Federal law states that the EPA must ensure that pesticides entering the marketplace do not cause “unreasonable adverse effects to humans or the environment”. To carry out this mandate, the EPA assesses a variety of factors, including data on the pesticide’s chemistry, human health effects, environmental effects, etc. These data help inform the label language ̶ if the label is appropriately followed, the pesticide product should not cause unreasonable adverse effects to humans or the environment. For example, if a pesticide is highly toxic to fish, the hazard statement of the label would include a sentence like “Do not allow pesticide to enter or run off into storm drains, drainage ditches, gutters, or surface waters”. Applicators can be protected from unreasonable adverse effects by complying with precautionary statements like “Avoid contact with eyes” and “Wear chemical-resistant gloves”. Pesticide use/application rates are set to prevent hazardous quantities from entering the environment, including the infested plants you would like to consume. 

Given the label’s critical role in minimizing a pesticide’s negative impacts, it is little wonder that the label is the law. Remember, if you use pesticides improperly, you are legally responsible for any consequences that may occur!

References:

U.S. Environmental Protection Agency. Label Review Manual. https://www.epa.gov/pesticide-registration/label-review-manual

American Association of Pesticide Control Officials. FIFRA Minimum Risk Pesticides – 25(b) Product Label Guidance. https://aapco.files.wordpress.com/2018/03/fifra-minimum-risk-pesticides-label-guidance-3-12.pdf

By Niranjana Krishnan, Assistant Professor, Department of Entomology, and Maryland Pesticide Safety Education Program Coordinator

Are Baldfaced Hornets Friends or Foes?

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Distinctive white marks on their heads give baldfaced hornets their name.
Photo:  Johnny N. Dell, Bugwood

It’s been a good year for baldfaced hornets. Many people have contacted me to report their grey papery nests in trees or hanging from the eaves of their homes.

So, are they good guys or bad guys? Do they need to be controlled? It’s a matter of making an informed choice. So here are the facts.

First, baldfaced hornets aren’t hornets at all. They’re black and white yellowjackets that nest in trees, shrubs, and on buildings. Since they kill many harmful pests, they are considered beneficial.

It’s only when their nests are nearby that they pose a potential threat from stinging. Left alone, they tend to be benign. They usually only sting to defend their nests. I’ve had several walk up and down my arm peaceably. 

The white marks on their head earn them their “baldfaced” moniker. Workers measure about three-quarters of an inch long and queens are slightly larger.

In the spring, overwintering queens emerge from tree bark, stumps, logs, rock piles, and other protected spots. Each queen builds a small nest with a few brood cells, lays eggs, and gathers insects to feed the growing workers.

When those workers become adults, they take over the housekeeping duties, building and taking care of the nest, foraging for food, and tending to the growing family from eggs laid by the queen.

Baldfaced hornets’ football-shaped nest is an engineering marvel. To that first handful of paper cells, workers add layer upon layer of hexagonal combs similar to those of the honey bee.

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Buckwheat: Pollinator Friend and More

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buckwheat flowers with a pollinators
Buckwheat flowers.

Where I grew up, we did not have a county fair, but instead a “Buckwheat Festival” which celebrated buckwheat pancakes. I’ve often heard stories about “old timers” planting buckwheat because it could thrive in poor soils. Buckwheat is not as well known or common as it was several years ago; however, it does have the potential to be a great addition to your landscape and would be a wonderful summer cover crop, which is just one way to help improve soils for a more climate- resilient garden.

Positives about buckwheat include that it matures quickly, is easily seeded by broadcasting, is relatively inexpensive to purchase by seed, is not “fussy” about where it grows, and germinates quickly. It does not mind low-pH soils and can even out-compete weeds! It has shallow roots and is easily terminated — so planting a new crop after it is no problem — or, if it is still growing in the fall of the year, a frost will kill it. Lastly, it is a wonderful nectar and pollen source for a wide variety of insects. 

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Mosquitoes Take a Bite Out of Summer Fun

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Asian Tiger Mosquito. Photo: Ary Farajollahi, Bugwood.jpg

Mosquito season is (slap) upon us. Fortunately, there are (slap) many things you can do to minimize their (slap) nuisance. 

Only females bite, so that’s the good news. Only half of them are out to get you.

Mosquitoes need water. They have four stages of development – egg, larva, pupa & adult – (complete metamorphosis for you geeks) and spend their larval and pupal stages in water.

Mosquito larvae hang upside down in the water and get air from a siphon tube. They wiggle when disturbed, mildly entertaining. Pupae look like commas and are called “tumblers” for the way they move.

After a snack (cue ominous Dracula music,) adult females lay their eggs on water. They can do this in as little as a teaspoon of water. Yes, a teaspoon. So eliminating standing water is crucial to control.

Water collects in obvious places like ponds and marshy areas. But it also pools in birdbaths, rain barrels, wading pools, pot saucers, gutters, and downspouts.

You also find mosquito-attracting water in used tires, plastic toys, recycling bins, tarps, grill covers, tree stumps, wading pools, pet dishes, and more.

So, eliminate water traps such as used tires. Screen rain barrels. Twice a week add fresh water to birdbaths and pet dishes and remove any water you find any of the other hiding spots above.

Clear debris from gutters and downspouts and cover the opening to corrugated drain pipe on downspouts with pantyhose held with a rubber band. Very sexy.

If you have a pond or rain barrel, use mosquito dunks, donut-shaped disks containing Bti, an organic biological control. Getting goldfish or mosquito fish (Gambusia) that eat mosquito larvae also is helpful.

Part two of mosquito control – after managing standing water – is personal protection. Mosquitoes find us very tasty so we need to know how to keep them at bay. 

Most mosquitoes are active from dusk to dawn, so avoiding activity then is helpful. If you’re having a party or just want to sit on your deck, hook up a fan. The breeze is a serious deterrent.

For more protection, use repellants with DEET, picaridin, Icaridin, or oil of lemon eucalyptus. Wear long pants and sleeves since mosquitoes can bite through clothing. Clothing treated with the insecticide permethrin also deters mosquitoes.

Citronella candles, mosquito lamps, and butane-powered repellers aren’t very effective. Bug zappers kill few mosquitoes but many beneficial insects. And mosquito traps actually attract more mosquitoes. 

Everyone’s instinct is to spray, spray, spray, but sprays kill predators and pollinators. You’re killing the good guys that help control many harmful pests.

Birds, bats, frogs, lizards, and dragonflies eat mosquitoes. So create good habitat for them by planting native plants, adding birdhouses and birdbaths, and avoiding chemicals.

To keep mosquitoes from invading your home, use tight-fitting screens on windows and doors and replace tears quickly.

The newest bad actor is the tiger mosquito which is active throughout the day. Bigger, badder, and with striped legs, it is a brute.

Be a skeeter beater. Seek out and eliminate standing water. Dress for protection. And practice active avoidance. Combine multiple controls for less slapping and more smiling. 

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

Select Ground Covers for Your Landscape Carefully

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Plants that are used as ground cover can provide great services throughout the landscape as they can fill in areas that might otherwise be left bare or covered in mulch. Ground covers can be used to help reduce maintenance chores by preserving moisture and preventing weeds. 

If you are looking for a ground cover plant, consider adding a native ground cover. Non-native ground covers and vines can be the plants of nightmares, as the characteristics that we like about them (aggressive, can take over weeds, need little care once established, etc.) are often the characteristics that make them terrible offenders when they escape into natural areas. A great field guide on this exact topic is Plant Invaders of Mid-Atlantic Natural Areas. 

Since it’s prime planting season in Maryland, here I highlight three herbaceous plants that are often used as ground covers that can quickly take over. For a more detailed list of some of the other ground covers that are concerning, check out this webpage, Invasive Vines and Groundcovers.

a covering of English ivy under a tree
near a forest edge English ivy is all over the ground and climbing up trees
English ivy (Hedera helix). Photo: M. Talabac, University of Maryland Extension

English ivy (Hedera helix) is sometimes just called “ivy” or “European ivy”, which reiterates the point that it is not a plant that is native to the United States. This evergreen, vining plant is one that you should be aware of as it can take over areas through the spread of seeds and through underground stems. It thrives in shade, is drought tolerant, and once established, it creates a thick, dense mat of foliage that can outcompete many perennials. It’s even been reported that it can damage homes/walls where it grows up and even penetrates the bark on living trees and strangles them. A study done in February of 2021 found that there are at least 5,000 trees in Takoma park could be lost because of English ivy. English ivy also serves as a reservoir for bacterial leaf scorch, a disease in maples, oaks, and elms.

For more information on English ivy, visit these webpages from the University of Maryland Extension: English Ivy and Invasives in Your Woodland.

Periwinkle (Vinca minor) close-up of purple flowers (left), and spreading along a staircase in Great Falls Park (right). Photos: M. Talabac

Periwinkle is a common plant that many people will recognize by its attractive shiny green leaves and purple-white flowers. There are actually two types, Vinca minor and Vinca major, unfortunately, both are considered invasive species and spread quickly vegetatively by root pieces (digging) and rooting at tips and nodes that contact the ground.

The third plant is bishop’s weed or goutweed (Aegopodium podagraria). Once established, this plant easily gets out of hand and is very difficult to remove. It is on the Maryland Department of Agriculture’s list of plants considered for regulation. Joyce Browning with the University of Maryland Extension in Harford County recently posted a video about bishop’s weed.

It can be overwhelming when considering adding plants in troubled areas. A great resource for ideas is the University of Maryland Extension webpage about Lawn Alternatives. 

Remember that you can help mitigate the negative effects of invasive plants on local ecosystems by not adding them to your landscape. However, if you already have some of these plants, you can also manage them correctly by keeping them contained in certain areas and eliminating their spread into natural areas. Never place yard trimmings into natural areas, and remove the seeds before they can be spread by wind, rain, and/or animals. As you are adding plants to your landscape, please check out these great resources for non-invasive plant suggestions: 

Landscaping with Native Plants- Maryland Native Plant Society 

Keystone Plants by Ecoregion- National Wildlife Federation

Resources on invasive plant identification: 

Plant Invaders of the Mid-Atlantic Natural Areas (PDF)

Do Not Sell! Ornamental Invasive Plants to Avoid with Climate Change (PDF)

Everyone can help in the fight against invasive plants! Check the University of Maryland Extension website for an Introduction to Invasive Plants in Maryland and more information on how to reduce them. The absolute best way is to just never plant or introduce them into your landscape. 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

Beyond Broccoli Part Five: Love Them and Leaf Them

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Welcome back to Beyond Broccoli, the brassica blog series! You can find previous entries here. In this edition we’re going to explore the plants in the genus Brassica that are grown for edible leaves.

I think the best place to start is on the shores of the Mediterranean. This is likely the home of the wild relatives of what became the domesticated forms of Brassica oleracea. They would have looked something like what we know as kale. The lineage of these wild plants is still fairly obscured, but if you want to read more about it check out this scholarly article.

The kales we grow today are actually not all one species. Most of them are Brassica oleracea var. acephala(or Acephala Group), but the super-hardy kales like Red Russian and Siberian are Brassica napus var. pabularia, related to rutabaga. Even the B. oleracea kales are amazingly varied, having been bred for millennia into forms with curly leaves, flat leaves, small or enormous leaves, leaves with blue and purple tints, the cabbagey-looking ornamental kale that landscapers plant at the corner to carry through the winter, and kale that forms stems taller than people that are made into walking sticks. (I wish we could grow that kind here, but our heat and humidity don’t agree with it. At least you can read about it.) My favorite kind to grow and eat is the blue bumpy type known as Tuscan, Lacinato, or Dinosaur kale.

Looks like dinosaur skin, I guess? Kid- and adult-friendly!
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