#TeachingTuesday: Cephalotaxus, Japanese Plum Yew

Cephalotaxus harringtonia ‘Pedunculata’
Photo credit: Maryann Debski
JCRA Photo Collection

Today our crews reviewed an interesting evergreen shrub, Cephalotaxus harringtonia, or the Japanese plum yew. Although it has a similar name and similar appearance, it is not the same thing as true yews, which are in the Taxus genus. These shrubs are much more tolerant of the hot, humid summers of the south than the English and Japanese Taxus species. They are also shade tolerant and deer resistant, so all they really need is some protection from drying winter winds and a well-drained site.

Japanese plum yews are highly valued for their deep green evergreen foliage and slow growth rate, meaning they are very low maintenance. It’s hard to name another evergreen shrub so versatile. Their graceful arching branches need not be pruned much at all, and there are several cultivars that exhibit specific growth habits for different applications, such as ‘Prostrata’ for a low, spreading shrub or ‘Fastigiata’ for an upright columnar shrub, great for low- to medium-height hedges. ‘Duke Gardens’ is another well-known cultivar, developed right here in NC at Sarah P. Duke Gardens in Durham (420 Anderson St, Durham, NC 27708). You can see the original plants in the Terraces above the koi pond. To see a collection of several different types of Cephalotaxus, visit the JC Raulston Arboretum at NC State (4415 Beryl Rd, Raleigh, NC 27606).

ID Tips

  • The leaves are long, flat, and linear with pointed tips, arranged spirally around the stems, in two planes, forming a distinct V-shaped trough.
  • On C. harringtonia ‘Fastigiata,’ rather than appearing in two flat planes, the leaves along the stem will show a bottlebrush effect, and will start small, and gradually get larger, then become small again and repeat.
  • On the underside of the leaves, there are two grayish bands.
  • These shrubs do not produce cones, but rather “arils” which are naked seeds, an evolutionary step between cones and actual fruit. There is a fleshy covering over the seed that is open at the bottom, and is shaped somewhat like an olive and is brown to reddish brown in color.
  • The arils and leaves are toxic if ingested, but are safe to handle.
Cephalotaxus harringtonia ‘Duke Gardens’
Photo credit: Mark Weathington
JCRA Photo Collection

#TeachingTuesday: Peonies!

Paeonia lactiflora
Photo credit: Debra Singer-Harter
JCRA Photo Collection

What gorgeous weather we had today, after all those storms on Monday! Today we reviewed one of the showiest garden plants with our crews, the peony (Paeonia sp.). Peonies bloom in mid- to late spring, and winter chilling is required in order for them to bloom, so they do not perform well in the deep south. Luckily in NC, we tend to get more chilling hours than many other southern states. Peonies can be very long-lived, and may be passed down like family heirlooms through generations of gardeners. I (Caitlin) knew a lady in Alexandria, VA, who said that her peony was over 113 years old, and had been passed down by her great grandmother. What a beautiful way to keep memories alive.

Peonies are generally used as flowering specimens in borders, perennial gardens, and cut flower gardens. For optimal growth, they require at least 6 hours of sun exposure and a well-drained soil. Botrytis blight and leaf blotch are the most common disease problems, so make sure there is adequate air circulation around your plants to help prevent these fungal infections. Japanese beetles or scale insects can sometimes cause issues as well. You may notice ants on your peonies because they are attracted to the sap excreted by the flower buds, but they will not damage the plants.

Maintenance Tips

  • Fertilize peonies in the spring when stems are 2-3 inches high, using a low nitrogen complete fertilizer. 5-10-5 or 5-10-10 would be appropriate choices.
  • Peonies are sensitive and easily burned, so do not allow fertilizer or uncomposted manure to come in contact with the plant stems.
  • Remove seed heads after flowering is finished to encourage large flowers the next year.
  • Understand the difference between tree peonies and herbaceous peonies. Herbaceous peonies go dormant in the winter and grow back from an underground crown, but tree peonies are shrubs. Herbaceous peonies can be cut back in the winter, but NEVER cut back a tree peony–it won’t grow back.
Paeonia suffruticosa ‘Shimadajin’
Photo credit: Maryann

Why isn’t my peony blooming?

There are many factors that may prevent a peony from blooming. Investigate to see which of the problems listed below might be causing the problem in your case.

  • The crown may be planted too deeply. The tips of the eyes (dormant buds) should be no deeper than 1 inch below the soil surface. Carefully dig up and replant at a shallower depth during late fall.
  • The plant may be too young. Peonies don’t generally bloom for at least the first three years after planting. Be patient!
  • The plant may have received too much nitrogen, which stimulates vegetative growth at the expense of floral production. Stop fertilizing for a year or two, and make sure you are using a low nitrogen fertilizer (the first number should 5 or less), and that you are applying the correct rate.
  • The plant may be located in an area that is too shady. Make sure the plant is getting at least 6 hours of full sunlight per day during the growing season, or move it to a new location in late fall.
  • If the peony is too crowded, it may not bloom. Make sure there is an adequate amount of space, or you may need to do some transplanting.
  • Nutrient deficiency can also cause a peony to not flower, but if this was the problem there would likely be other signs too, such as discoloration of the foliage (yellowing or reddening). Low nitrogen fertilizer or compost would solve the problem.
  • Insect or disease pressure could cause a peony to not flower, or in the case of Botrytis, the flower buds may drop off without opening. You will see clear signs if this is the problem. Make sure there is adequate air circulation around the plant.
  • Late freezes can kill the immature flower buds. Cover your plants in the afternoon or early evening to trap warm air before a late freeze is predicted, and take off the covers first things in the morning (large sheets work well for this).
Paeonia ‘Bartzella’ – Emerging in spring
Paeonia ‘Bartzella’ – In full bloom
Photo credit: Susan Baily
JCRA Photo Collection

#TeachingTuesday: Ligustrum and Proper Watering

Ligustrum japonicum ‘Texanum’

Now that temperatures are up in 80’s and everyone is hurrying to get trees and shrubs planted before the summer heat sets in, it’s a good time to review proper watering. The important thing to remember is that once a plant is showing signs of drought stress, other processes are occurring within the plant that can damage the long-term health of the plant and reduce growth, so ideally plants should be watering before they show physical signs of stress. However, at the same time, over-watering can cause just as much damage by reducing root growth, or even killing the roots, and eventually the entire plant.

So how do you know when it’s time to water? You have to check the soil!

Here are a few methods for checking the soil moisture content:

  • Gather up a handful of soil and try to press it into a ball. If it just crumbles, the soil is too dry to supply water to plant roots.
  • Use a soil probe to pull a sample from the ground near the plant roots to visually check the level of soil dryness. You should be able to see mostly moist soil that is darker in color with a small amount at the very top that will be much lighter in color and dry to the touch. This will give you a good idea of how much you should water. You can also use a soil probe after you have finished watering to check if the moisture has reached the root zone.
  • For planters or annual beds, the soil should be soft enough that you can check the moisture level by sticking your finger down 2-3 inches. The potting soil should feel cool and damp.

If plants are displaying symptoms of drought stress, it is important to get them watered deeply as soon as possible. Drought stress can cause long-term health issues and death, resulting in expensive losses in the landscape.

Drought Stress Symptoms:

  • Foliage develops a gray cast
  • Wilting of leaves and young twigs
  • Upward curling or rolling of leaves
  • Yellowing and browning of leaves, particularly along leaf margins and tips
  • Under-sized and off-flavored fruits, vegetables and nuts
  • Under-sized leaves; limited shoot growth
  • Blossom and fruit drop
  • Interior needle and leaf drop on conifers and evergreens
  • Iron chlorosis symptoms on foliage (leaf yellowing between veins)
  • Spider mite infestations

Long-Term Problems Caused by Drought:

  • Increased susceptibility to attack by insect borers
  • Increased susceptibility to certain plant diseases
  • Root death
  • Terminal dieback; dead twigs and branches
  • Diminished winter hardiness
  • Eventual plant death

A good rule of thumb is to apply 1 gallon of water per square foot of root zone once a week. This will vary depending on soil type, the type of plant, and its growth stage. New plants require more frequent water than established plants, and sandy soils lose water content more quickly than clay soils. Check new plants daily during hot weather! Checking once a week for the first year is a good idea for trees and shrubs.

This Japanese privet is about to be in full bloom. It’s waiting in our yard to be installed soon!

Ligustrum japonicum, AKA Japanese Privet

Japanese privet is not the showiest plant, but is a tough evergreen shrub tolerant of a variety of conditions making a great choice for many North and South Carolina landscapes. It is drought tolerant, salt tolerant (important for those on the coast!), deer resistant, and will accept a range of sun to partial shade, and most soil conditions except constantly wet/boggy. Some organizations list Japanese privet as an invasive species, but it is really the other species of privet such as L. lucidum, L. vulgare, and L. sinense that self-seed profusely into the environment. If you are still concerned, substitute a native species such as Illicium or a native holly. Take care that children do not eat any part of this plant–both the berries and leaves are toxic.

ID Tips and Maintenance

  • Compared to other privets, Japanese privet has thicker, more leathery leaves, and wavier edges. Several cultivars have enhanced this feature to develop quite curly leaves.
  • The flowers in the spring are in large white “panicles,” or groups of tiny flowers growing in a multi-stemmed bunch, like a crape myrtle.
  • The flowers develop into small, dull blue-black berries, similar in appearance to blueberries or elderberries. The berries are hard and may persist through the winter.
  • Privets look best when they are hand-pruned. Shearing causes a ragged appearance due to the large leaf size. It blooms most profusely if pruned right after flowering in late spring/early summer.
Leaf comparison of different Ligustrum species.
Photo credit: NC State University
Note the curled leaves. This is a natural characteristic and not a sign of drought stress.

#TeachingTuesday: Fuquay Varina High School Field Trip

Well it’s day late, but we wanted to share for #TeachingTuesday about the field trip we hosted for Fuquay Varina High School last Thursday! Ms. Moore brought a group of students from her Hort II/Honors class to learn about our company and the landscape industry as whole, as well as tour our facility and do some hands-on activities.

Scott (President), Herbie (Installation Manager), and I (Caitlin, Recruiting Specialist and Company Ambassador) started things off by introducing ourselves and talking about the business and how we each contribute our skills. It was a particularly meaningful group for Scott to speak with, since he is a FVHS graduate himself! This group of students was the most engaged we have ever had. They asked so many insightful questions, such as what our biggest failures were and how we came back from them, how Scott decided he wanted to start his own business and how he was able to build a client base, what was a company goal that we have not achieved yet, and much more.

After that, Blake (Operations Specialist) took the students on a quick tour of the shop and the yard, ending in our equipment storage area, where we had some activities set up. First, the students put together their own planters with summer annuals to take home (with Mother’s Day right around the corner, many students mentioned they planned to give away their planters to their mothers).

Next, we had a paver laying competition! Ms. Moore broke the students into two groups, and they each battled to be the first to fill a 5′ x 5′ square with a random pattern using 4 different-sized paver types. Here’s the catch:

  • No two pavers of the same size could be placed side-by-side
  • Joints could not exceed 38″ in length

Through this activity, students naturally gained experience in teamwork and problem-solving, but they also learned practical industry knowledge, such as the definition of a “joint” in hardscaping, and why keeping the length short is important.

Scott gives some tips on the layout.
The winning team!
So close! Only a few blocks left.

After we all ate lunch together (sandwiches from Bagels Plus!), we talked a little bit about different job opportunities for high school students within our company, and gave out frisbees to everyone. One of the students (Sydney) actually worked with our floriculture division last summer, and two of the other students (Clarissa and Lexi) just started working with us yesterday, helping organize flower orders after school. We love supporting Fuquay Varina High School students! Go Bengals!

#TeachingTuesday: Boxwoods

Boxwoods are one of the most ubiquitous shrubs in the American garden. They have been popular for centuries throughout Europe and the US, because they are so versatile; boxwoods can be pruned into elaborate topiaries, sheared into formal hedges, or allowed to grow naturally as elegant evergreen accents in the landscape. There are several varieties of boxwood–multiple species, hybrids, and cultivars within those groups, but they all share similarities. Today we’re going to touch on proper pruning techniques, a threatening new disease to watch out for, and identification tips for the most common types of boxwood.

Large natural boxwoods in the landscape.
Photo credit: Herbie Champion

Pruning Tips

There are two main methods of pruning to use with boxwoods: thinning and shearing. Thinning is important for maintaining the health of all boxwoods, while shearing is used to sculpt the shrubs into a desired shape, which is purely a personal choice, and may look rather artistic (or horrifying if done poorly!). In addition, shearing without ever thinning can cause a lot of issues both for the health and appearance of boxwoods.

Thinning only needs to be done once a year in the spring, after the cold weather ends but before the shrubs are fully leafed out, usually between mid-February to May 1st, depending on your location. In coastal South Carolina, pruning could begin earlier, while residents in the mountains of North Carolina will want to wait as late as possible.

Thinning involves removing branches evenly all over the shrub to increase light penetration and air circulation within the center of the shrub. Essentially, leaves will not grow where there is no light, because it’s a waste of the plant’s energy. But it’s important to encourage growth in the interior, because the more leaves a plant has, the more food it can produce for itself, and therefore the more it will be able to grow and the healthier it will be. Additionally, poor air circulation encourages fungal diseases and insect infestation, so keeping a more open interior will help reduce pest and disease issues. To determine if your boxwoods need to be thinned, try parting the branches. If the shrub is so dense that it’s difficult to part the branches and look into the interior, you definitely need to thin. If when you part the branches, you see green growth only on the last few inches of each branch, you definitely need to thin. When you become more familiar with the process, you will be able to tell just by brushing your fingers over a boxwood specifically where it needs to be thinned.

To thin, just remove select branches, going deep into the interior of the shrub. A good rule of thumb is to only remove sections that are the length of the green growth. For example, if there are leaves going back about 8 inches on a branch, then remove 8″ sections in little pockets all over the top and sides of the shrub. It should look looser and even all over.

For more details about thinning, check out this article.

Shearing is done to shape formal hedges and create topiaries. It is done purely for aesthetic reasons, and does not improve the health of the plant in any way, and when done incorrectly, can be harmful to the plant. When shearing, be careful not to remove too much at once, especially if the shrubs have not been thinned, or you will end up with a brown twiggy skeleton of a shrub. In order to maintain tight formal hedges, they may need to be sheared a few times during the growing season. Make sure to thin the shrubs in the spring before vigorous growth begins, and avoid shearing during very hot periods. Shearing will encourage new growth, which will stress the plant during high temperatures.

To see some amazing, world-famous topiaries, check out Pearl Fryer’s garden in Bishopville, South Carolina. It’s open Tuesday-Saturday from 10am-4pm, year round. There is no entrance fee, but donations are encouraged. The collection includes boxwoods, but also a multitude of other species.

Boxwood Blight

Boxwood Blight is a fairly new fungal disease with the potential to wipe out boxwood populations on the east coast. It’s currently in Pennsylvania and other northern states, but could move to NC and SC. You can read in-depth information here, in a publication by NC State. Avoid bringing this disease to your property by only buying boxwoods from reputable sources and disposing of boxwood products such as live wreaths or stems from floral arrangements in the trash, and not in your compost.

Boxwood hedges can form lovely backdrops for other showier plants, such as annual flower plantings.
Photo credit: Misael Gonzalez

ID Tips

  • Most people are familiar with boxwoods, which are evergreen and have small leaves, with no prickles, thorns, or cones.
  • Boxwoods are most often confused with Japanese holly, which is also evergreen with no prickles, and has leaves of a similar size and shape. A simple feature to tell boxwoods and hollies apart is the leaf arrangement: boxwoods will always have leaves in opposite pairs, while the leaves of hollies will always alternate along the stems.
  • Boxwood leaves have smooth edges, while Japanese holly leaves have “crenate margins”, meaning the edges are scalloped.
  • What is the difference between English, American, Japanese, and Korean boxwoods? Well, English and American boxwood are the same species, Buxus sempervirens, and Korean boxwood (Buxus microphylla var. koreana) is actually a variety of the Japanese boxwood species (Buxus microphylla). The English/American boxwood differs from the Japanese/Korean boxwoods in many ways, but the easiest way to tell is that the tip of the leaf is pointed, while Asian boxwoods have a rounded point with a small indentation at the very tip (like the shape of a rounded “W”).
Formal gardens with tulips and boxwoods.
Photo credit: Robby Tackett

#TeachingTuesday: Redbud

The redbud, Cercis, is one of the most beautiful native trees in the eastern US. Cercis canadensis, the eastern redbud, is the one we see in the Carolinas most commonly. The tiny light purple/pink flowers (there are also white varieties) open in early spring, and are actually edible! They make an elegant garnish for salads.

The tree itself is an understory tree, like dogwoods, and stays small–about 15-35′ in height, depending on the cultivar and environmental factors. They can have a single trunk or multiple trucks, and usually have a somewhat zigzag habit to their branches. There are also weeping cultivars available, such as Cercis canadensis ‘Covey’ and Cercis x ‘Ruby Falls’. There is also a selection of leaf colors available, with the newly emerging foliage varying from green to bright golden and red to deep purple, with the leaves developing into solid green, variegated green and white, or purple later in the season. It is truly a versatile and highly attractive tree, and also attracts and supports native pollinators.

A redbud tree at the JC Raulston Arboretum.
Photo credit: Bob Hauver, the JCRA Photo Collection
Newly emerging foliage on this cultivar is red, then lightens to gold and finally green. Cercis ‘Rising Sun’.
Photo credit: Jimmy Sumerrel, JCRA Photo Collection

Care and Maintenance

Redbuds should be planted in locations where they will have moist, well-drained soil, but not overly saturated. They will grow in filtered light, but look best with more access to sunlight. However, some types are prone to sunburn on the leaves if they aren’t sheltered from the blazing afternoon sun. There are some fungal diseases that can cause cankers and dieback, so make sure the trees are kept healthy with adequate water, correct pruning technique, and proper mulch.

Pruning should only be done to remove dead branches, suckers or “water sprouts”, or branches that cross or rub against each other, causing injury.

ID Tips

  • Redbud leaves are distinctly heart-shaped with smooth edges.
  • The leaves are arranged alternately along gently zigzagging branches.
  • The flowers are very small and resemble sweet pea flowers, because redbuds are in the pea family. Flowers may grow on any surface of the tree, even from larger branches and the main trunk!
  • After blooming, the flowers develop into pods resembling snow peas which will turn brown and eventually drop off the tree. They are not usually unsightly, as the foliage emerges right after flowering and will hide the pods.
Flowers bloom alongside last year’s pods.
Flowers can even bloom on the trunk of the tree.
Photo credit: Jeanne Wilkinson, JCRA Photo Collection.

#TeachingTuesday: Azaleas

Even if you don’t do any gardening or landscaping at all, if you live in the south, you probably know what an azalea looks like. In April, you can drive around any neighborhood to see the brightly colored shrubs completely covered in blooms. Many azaleas originated in Japan, but are now icons of the southern garden, with both heirloom and new varieties available. There are also beautiful native varieties from right here in the Carolinas.

The Right Plant for the Right Place

Azaleas are woodland understory shrubs, so they do best in dappled shade, protected from winds and harsh sunlight. Azaleas planted in full sun are highly susceptible to lace bugs, which feed on the sap through the leaves. In a bad infestation, the leaves may turn a silvery white color, and over time the health of the shrubs will decline. Avoid having to use chemicals to protect your plants by planting them in an appropriate location from the beginning.

Azaleas tend to develop root rot easily if the soil is not well-drained, but they are also shallow-rooted, and may require irrigation during dry periods in some landscapes.

Damage from lace bugs.

When Do I Prune My Azaleas?

The answer is: it depends! Before you prune any tree or shrub, you should always ask yourself what the goal is. If you’re not sure, you probably don’t need to prune! Azaleas have an interesting branching structure which makes them more challenging to prune than many other common shrubs. Essentially, there are two main methods for proper pruning of azaleas–one for general shaping and thinning, and one for rejuvenating old, overgrown shrubs.

  • Thinning or “Pocket Pruning”: identify the branch or stem that needs to be removed, whether it is dead, diseased, leggy, broken, or just needs to be removed to improve air circulation within the shrub. Trace the stem back to where it connects to the main trunk or another branch, and prune it close, without leaving a stub. Thinning should be done AFTER blooming in the spring, in order to preserve the next year’s flowers.
  • Rejuvenation/Renewal Pruning or “Heading”: This pruning method is more severe, and should only be done if absolutely necessary, as it will alter the natural shape of the shrub. When azaleas become very old and overgrown, sometimes the best thing to do to improve their health is to cut them back to about 6-12″ above the ground and allow them to regrow. This type of pruning is done without regard to the location of the branch unions, so it will look very unattractive until the shrubs begin to grow back. This should be done in the late winter, before the new growth begins, which means that the flowers will be sacrificed for the year.
Azaleas look best in naturalistic masses, under trees that provide protection from the sun.
Photo credit: Marco Acevedo

ID Tips

Most everyone knows an azalea when they see one, but here are a few tips for when they are not blooming:

  • The leaves are elliptical in shape, ranging from very small to 1 or 2 inches long, and area covered with very fine hairs. On some varieties it may feel like a velvety fuzz, and others it may feel like sandpaper.
  • The twigs are covered in fine reddish-gold hairs.
  • The branches and twigs grow in “trusses,” which means that one branch will reach a certain point, then suddenly branch out into a cluster of branches radiating from one point. Each of those branches will grow, then branch off into their own clusters.
  • There are both evergreen and deciduous varieties of azalea, and some azaleas even bloom twice in one year, once in the spring, and once in the fall.
Encore azaleas blooming in November.
Photo credit: Tony Stewart