Elfin thyme has an almost magical look, as if it belongs in a fairytale, or better yet, a fairy garden. Thymus serphyllum is certainly at the top of my list of groundcovers that work in full sun and will tolerate moderate foot traffic. It has many uses in the landscape, from filling in around pavers, cascading lavishly over rock walls or as a stand-alone specimen in a rock or crevice garden. I have even seen grass lawns replaced with elfin thyme. It grows barely over an inch tall and is covered profusely with tiny purple to magenta flowers in summer. The flowers, though small, are loaded with nectar and are a sweet feast for bees and butterflies. The foliage itself is aromatic, though T. serphyllum is not used in cooking as often as its more common cousins Thymus vulgaris or Thymus citrodorus.

is native to most of Europe, northern Africa and parts of Asia. In the wild, it can be found growing in full sun in well-drained soils in a variety of settings including rocky outcrops, gravel eskers, hillsides, etc. The key cultural conditions are full sun and well-drained soils, and these conditions must be met if elfin thyme in to thrive in a garden setting. It is attractive even when not flowering, when it forms a dense dark green mat that upon close examination is formed by highly compacted leaves. The leaves are fringed with very fine translucent hairs which help the plant collect water during times of dryness, and elfin thyme is thus somewhat drought tolerant. It is extremely cold hardy, handling winter low temperatures of -25°F. There are few gardens in the continental U.S. that T. serphyllum would not thrive in, again provided it has full sun and well-drained soil. A 4-inch pot will spread to a diameter of about 18 inches in a couple of years.

Why grow Thymus serphyllum?

• Elfin thyme has beautiful purple to magenta flowers that bloom from June–September.
• It is pollinator and butterfly friendly.
• It is drought tolerant.
• Propagates easily from cuttings.
• Use as a grass lawn replacement.
• Deer and rabbits will leave it alone.
• Tolerates moderate foot traffic.

Taking the time to care for plants or visiting your local park helps to relieve some stress of the COVID-19 pandemic, says Angela Moles, plant ecology professor at University of New South Wales (UNSW).

“My garden at home attracts the local wildlife, so when rainbow lorikeets come to visit for the nectar from the native flowers, our kids love going outside to watch them — just one of the many benefits of having a good garden,” she says. “I also spruced up a shared patch of grass in my community with lots of plants — my neighbors stopped to talk to me, shared gardening tips and said, ‘Wow, well done, that looks so much better.’”

Philippa Specker, a PhD and Master of Psychology candidate at UNSW says taking the time to care for plants can be used as a self-soothing or distraction technique to help people cope with negative emotions like fear, sadness and anger.

The South Korean government is even paying attention to how plants improve mental health. According to NBC News, South Korean officials distributed 2,000 “pet plant kits” to people living in self-quarantine to help them battle depression and other mental health conditions brought on, or exacerbated, by the pandemic. The government handed out Sanhosu (coralwood in English), which is associated with bravery, Lee Yong Kwon, director of the forest education and healing division at the Korea Forest Service, told NBC. Lee says a plant can “ease the loneliness often felt by people in isolation by providing companionship and bonding ...”

Furry friends

Photo s by Kelli Rodda

I ordered more houseplants during quarantine and added more shrubs and perennials to my landscape during the lockdown. I’ve always agreed that gardening is therapeutic. But it was the unconditional love of my dogs and the aloof love of my cat (Roxie, Radar and Felix are pictured below) that helped my mental state the most these last few months. (Sorry, honey. You’re a wonderful husband, but pets are just better at keeping depression at bay.)

The American Heart Association (AHA) says pets can help mental health because they lower work-related stress. Working from home allowed us to spend working hours with our pets. Pets can also help increase productivity and help manage anxiety.

Whether it’s a haworthia, an azalea, a Labrador or a tabby, plants and pets help quell feelings of isolation. Keep that message flowing to consumers, even after the pandemic subsides.

My hope is that you had something or someone to help you cope this year.

Liverwort

Liverwort is primarily a problem in herbaceous perennials, woody ornamentals or crops with long production cycles with a dormant or vernalization period where crops remain damp for long periods of time. There are thousands of liverwort species with Marchantia polymorpha being the most common one prevailing in greenhouses and nurseries, according to Marble et al., 2017.

Liverwort, including M. polymorpha, prefer cool temperatures, low ultraviolet (UV) light radiation, high fertility and moist or damp substrate. It reproduces rapidly in the presence of overhead irrigation, poorly drained or moist areas. The optimum temperature for vegetative growth is 64-72 °F. These environmental conditions are common inside greenhouses and nurseries, and the organism thrives and spreads rapidly once established in containers.

Liverworts form dense, prostrate mats covering the soil or container media surface. In container production, liverwort becomes highly competitive with the ornamental crop for water, nutrients and space. The liverwort mat can prevent the irrigation water and fertigation from reaching the root zone of the ornamental crop and can repel water when dry. As a result, the overall quality and market value of the ornamental crop decreases.

At temperatures of 50-59 °F, M. polymorpha develops sexual structures. Stalked, umbrella-like male and female reproductive structures are borne on separate thalli. Sperm cells produced by the antheridia travel via water (rainwater or irrigation splashing on the upper surface of the antheridiophore) to fertilize the eggs on the undersides of the archegoniophore, according to Marble et al., 2017. After fertilization, spore development takes place. Once they mature, they get dispersed by wind or water and germinate on moist substrate under suitable growing conditions.

Managing liverwort in container production can be challenging. For a successful liverwort control, it may require a combination of herbicide applications along with proper cultural and sanitation practices. There are very few herbicides labeled for greenhouses, as there can be phytotoxic effects on the ornamentals.

For more information on pre- and postemergence herbicides that have shown some degree of liverwort control and are safe to apply to ornamental plants in nurseries or greenhouses, visit www.canr.msu.edu/resources/identifying-and-managing-liverwort-in-michigan-nurseries-and-greenhouses

Even the best herbicides will not provide effective weed control if they are not applied accurately and uniformly. Too little product results in poor weed control and higher hand-weeding costs. Too much can injure crops, reducing the number available for sale. Most granular herbicide labels contain some recommended settings for common application equipment. However, these recommendations are just starting points. To obtain the correct dose, you need to calibrate the spreader. Spreader calibration is essentially a very simple process:

• Measure the width of spread;
• Apply the granules to a small area;
• Measure the amount applied to this area;
• Compare this amount to the desired dose and adjust the spreader settings until the desired output is obtained.

Maintaining a consistent speed

Both your walking speed and the speed at which you turn the spreader handle will influence the rate at which the product is applied. A consistent speed will help maintain a uniform application rate and distribution.

For walking speed, measure a distance of 100 feet in an area that is similar to the location where you will be applying the granules.

Using a stopwatch, determine how long it takes to walk 100 feet. Most spreader manufacturers recommend walking about 2 to 3 mph. At 3 mph it takes about 23 seconds to walk 100 feet. A 2-mph pace requires about 34 seconds per 100 feet. Use a portable metronome or smart phone app to help keep a consistent walking speed. Experiment with a few different settings until you find one that allows you to walk at the desired pace. To achieve a 3-mph pace, a good starting point is between 99 and 103 beats per minute. But this number will be different for different applicators.

For handle cranking speed, turn the spreader crank at a consistent speed that is easy to maintain, generally one rotation per second.

You can practice with the metronome set to 60 beats per minute until you can walk with a consistent pace.

Spreader calibration step 1

The first step is determining the effective swath width and distribution pattern.

Granular spreaders do not distribute the same amount of material across the width of the treated area. More granules are deposited directly in front of the applicator than at the edges and the applicator will have to overlap each pass when applying herbicides. Therefore, you need to determine the effective swath width. The effective swath width will be narrower than the entire width of spreader throw.

Supplies needed:

• Granular spreader
• Herbicide of choice
• 7 to 9 containers such as catch bins, trays, or 1-gallon (3 or 4L) nursery pots lines with plastic bags
• Measuring tape
• A small scale (able to measure 1 gram)
• Metronome (battery operated or smart phone app)
• Stopwatch
• Numbered bags/jars to hold herbicide granules
• Personal protective equipment

Steps

1. Set out the catch pans or bins 2 feet apart on center, perpendicular to the direction you will be walking (Figure 1). Place the pans on a flat, dry, and empty nursery bed covered with landscaping fabric or plastic.
2. Mark a starting point about 20 feet in front of the center box. Mark a point along your walking path to open the hopper (at least 12 feet in front of the center box).
3. Practice walking toward the boxes at a consistent pace, using a steady handle cranking speed and stepping over the center box (use the metronome).
4. Fill the spreader at least 1/2 full.
5. Use the center rudder position (or just right of center).
6. Adjust the spreader to the herbicide manufacturer’s recommended output setting and spread granules while walking toward and over the boxes. Open the hopper at least 12 feet in front of the center bin and always walk toward the bins from the same direction. Keep the hopper open until just past the catch bins. Repeat the process at least two more times. When spreading, start turning the handle before you open the hopper and continue turning the handle after closing the hopper until no more granules spread out. This helps reduce spreader jamming.
7. Weigh the granules collected in each bin.
8. Measure the weight of granules collected in the center bin. Divide this number by two and find the collection bins on either side of center that have about half as much product as the center bin. The distance between the two bins is the effective swath width (Example A).
9. To determine the distribution pattern (Example B), use a piece of graph paper to chart the amount of granules in each bin and draw a line through the center (Figure 2). If the pattern is lopsided, plan to spread granules in one direction or make two passes in opposite directions over the same path.
10. If the test site was dry, you can sweep up the granules and reuse them.

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Example A: Determining the effective swath width

In this example, the weight of the herbicide collected in each bin is recorded in the chart below.

• 2.4 grams were collected in the center bin. Half that amount would be 1.2 grams.
• The bin 4 feet to the right of center contained this amount.
• On the left side, the area to receive 1.2 grams of material would be about halfway between the bins 2 and 4 feet left of center.
• Thus, we would conclude that the effective swath width would be from about 3 feet left of center to 4 feet right of center, or 7 feet wide. This is the width used in

Example B: Determining distribution pattern

Graph the amount of granules in each bin (Figure 2). This particular distribution pattern is balanced with similar amounts spread to the left and right. However, depending upon the granule, the spreader, and the dose applied, the amount spread to the right may be greater than the amount applied to the left.

Alternative swath width method

If you don’t have a scale, use this technique developed by NC State University pesticide education specialist Dr. Wayne Buhler. Use a clear seven-day pill organizer to visually estimate swath width. Caution: clearly label the box as having been used with pesticides and keep the box in the pesticide storage facility.

Label each compartment with the number of feet from the center. Keep left and right of center orientation clearly marked.

After collecting granules as described in steps 1 through 6, use a funnel to put the contents of each collection bin into the corresponding sections of the pill box.

Locate the compartments with about 1/2 as much product in them as the center compartment. This allows you to find your swath width and basic distribution pattern.

Spreader calibration step 2

The second step is determining the application rate.

1. Fill the hopper on the spreader at least 3/4 full of product.
2. Weigh the filled spreader and record the weight.
3. Operate the spreader over a known distance (at least 25 feet).
4. Reweigh the spreader and subtract the current weight from the original weight to determine how much product was used.
5. Calculate the area covered (distance the granules were spread multiplied by the swath width of the spreader).
6. Calculate the dose (weight of granules used divided by the square feet of area covered).
7. Adjust the spreader output setting or your walking speed until your application dose is within 10% of the labeled (or target) dose.

Example C: Determining the Dose

• Assumptions:
• Labeled (target) herbicide dose: 150 pounds/acre
• Effective swath width: 7 feet
• Length of walking area: 30 feet
• Area = 210 square feet (swath width x length of area treated)
• Beginning weight of spreader with herbicide granules: 195 ounces (oz)
• Ending weight of spreader with herbicide granules: 186 oz
• Difference: 9 oz applied
• Convert ounces to pounds: 9 oz ÷ 16 oz per lb = 0.56 lb applied
• Calculate the dose:
• Divide the amount applied by the area to obtain the amount per sq ft:0.56 lb ÷ 210 sq ft = 0.0027 lb/sq ft
• Multiply by 43,560 (number of sq ft per acre) to obtain the dose in lb/A. 0.0027 lb/sq ft x 43,560 sq ft/ acre = 118 lb/A
• This dose is more than 10% below the target dose of 150 lb/A. Adjust the spreader settings (or walking speed) to allow slightly more output and repeat the process until the rate falls within the acceptable range (135 to 165 lb/A).

You will need to follow this calibration procedure for each herbicide.

For video demonstrations on spreader use, visit https://bit.ly/spreader-how-to; and to watch a calibration demonstration, visit https://bit.ly/spreader-calibration.

Dr. Joe Neal is a professor of weed science, extension specialist and department extension leader at North Carolina State University, https://weeds.ces.ncsu.edu/