Forsythia Foretells Spring

I spotted a single open flower on my Forsythia this week, a sure sign that spring is almost here. Bring it on!

Forsythia, commonly known as “Yellow Bells,” are old-fashioned, indestructible plants that spread to form large thickets. They are among the earliest of shrubs to bloom. Their arching stems are covered with unscented yellow bell-shaped flowers for several weeks before leaves emerge. Plants bloom on prior year’s wood, so prune thoughtfully. Do not shear into tight meatballs. Instead, use hand pruners to remove entire stems at ground level.

Forsythia (pronounced for-SITH-ee-ah) is hardy in zones 6-8. Its arching stems will reach ten feet in height, with an indefinite spread. It is not choosy about soil type or pH. It is easily transplanted, and rarely bothered by insects or diseases. Deer nibble on young plants but tend to leave larger, mature specimens alone.

In full bloom, this Forsythia hedge looks like a yellow ribbon winding its way through the garden.

Forsythias make a good informal hedge where area is sufficient. Avoid siting them in locations where their aggressive expansion might overtake weaker plants or invade the neighbor’s garden. Plant them in full sun for best flowering. Shrubs reach a height of  feet. Dwarf forms are available, but these also spread vigorously.

Cut a few branches with swollen buds to force blooms indoors.

Rhododendron Family - Part 3: Native Azaleas

Native Azaleas are less in-your-face showy than other members of the Rhododendron family, but they are my favorite. They are native to the US, unlike the popular Popsicle-colored, evergreen Asian Azaleas that are found in many southern landscape plantings.

The Natives are taller and more open than their Asian counterparts. They are deciduous, losing every leaf in winter. In spring, the flowers appear before leaves.  The vivid yellow, orange, red or pink blooms glow like torches in the woodland areas where they occur naturally. Given the proper soil (moist, acidic) and light (morning sun, afternoon shade), they perform well in home gardens also. When not in bloom, they fade into obscurity. They look best when incorporated into a natural area rather than jammed against a house foundation. A mature plant may reach 10 to 15 feet, so site accordingly.

There are more than a dozen species of native Azaleas. Many are fragrant. Clemson University has compiled a useful fact sheet, listing species, colors and bloom times. Find a link to their information by clicking here.

According to Alabama and Auburn University Extensions, there are several hybrid groups that are more heat tolerant than most: Aromi hybrids, Auburn series, Confederate series, Sommerville series, Strickland Azaleas, and Clarence Towe’s selections. My friends in the nursery world recommend ‘Admiral Semmes,’ a yellow-flowered shrub in the Confederate series as a strong performer. I cannot distinguish a Piedmont Azalea from a Pinxter Azalea. Both have pale pink flowers with protruding stamens that are beyond gorgeous. Bees, butterflies, and hummingbirds flock to all the native Azaleas. Unfortunately, they are also a deer favorite.

Plants may be propagated from seed or root cuttings. I have experienced failures with both, so will be content to purchase mine from a garden center. Native Azalea is the state wildflower of Georgia.

This ‘Admiral Semmes’ (a Confederate hybrid) is in full bloom, with flower trusses that would rival its showier cousins, the Rhodies.

Pinxter Azalea. Photo by Jerry King, Reidville, SC.

Close view of an ‘Admiral Semmes;’ flower.

The bud of a Flame Azalea inspired its name, since they look a bit like candle flames. This photo Image by Rebecca Matthews from Pixabay

Rhododendron Family - Part Two: Azaleas

If the south had a signature shrub, it would likely be Azalea. Anyone who has watched the PGA Masters golf tournament at Augusta National or traveled through Charleston, SC in springtime can identify the gorgeous members of the Rhododendron genus known as Azaleas.

Give Azaleas acidic soil with plentiful organic matter and partial shade. They especially like the filtered shade of tall pines, it seems. Too much shade and they won’t bloom; too much sun and the leaves get crispy. Stressed plants are susceptible to damage from lacewing insects. Azaleas have shallow roots, so should be irrigated in hot, dry weather. They will not tolerate drought or constantly wet, boggy soils. They are not heavy feeders, so little fertilizer is needed. The University of Georgia Extension has an excellent bulletin on selecting and growing Azaleas. Read it by clicking here.

A lanky plant can be made more attractive by removing awkward long shoots. To provide better air circulation, plants can be thinned by removing some of the inner limbs. Use hand pruners or loppers for either job. Electric hedge trimmers produce unattractive round blobs. It is best to do any pruning immediately after petals shed, to ensure that you are not removing buds that will become flowers next year. While I see many examples of Azaleas that have been pruned into a tight hedge, this is not the best use of the plant. Allow them to retain their native irregular shapes and they will look more graceful.

Azaleas come in all shades of pink, rose, red , lavender, purple and white. Many have attractive contrasting freckles. When I worked in a plant nursery, my customers’ favorites were pink ‘George Lindley Tabor’ and white ‘Mrs. G. G. Gerbing.’ (The latter is much more attractive than ‘Delaware Valley White,’ which seems to hold onto its spent blooms forever.) In recent years, a personal favorite are the Satsuki hybrid Gumpo (please, NOT Gumbo) Azaleas. Gumpos are dwarf, reaching only two feet. They have dense, evergreen foliage and bloom a little later than the more “traditional” types. They tend to be uniform in size, making an attractive foundation plant.

Azaleas put on an amazing show in April and May, then fade into obscurity the rest of the year — except rebloomers. The best known of these, Encore® Azaleas, have led nursery sales since their introduction. Encores are aptly named, since they rebloom in the fall, although the autumn show is never quite as spectacular as the spring performance. They tolerate more sun than most other cultivars.

Like other members of the Rhododendron family, all parts of Azaleas are toxic to both humans and pets. Deer prefer to munch on new, young, tender shrubs; they exert less damage on older, tougher specimens.

Rhododendron Family - Part 1: Rhodies

Rhododendrons, Azaleas, and Native Azaleas look different from each other, but all are members of the Rhododendron genus. When I first started learning about plants, I found this terribly confusing. It made me think of the Newhart television show from the 1980’s: “Hi, I’m Larry. This is my brother Darryl. This is my other brother Daryl.”

There are more than 800 species in the Rhododendron (pronounced rho-doh-DEN-dron) genus. This huge family can be divided into three main types. Those known as Rhododendrons have large, leathery evergreen leaves and rounded bloom clusters about the size of a softball. To make a distinction, I’ll refer to these as “Rhodies.” Azaleas and Native Azaleas have smaller leaves and may be evergreen, semi-evergreen, or completely deciduous. Rhodie flowers have ten or more stamens; azaleas have five stamens in their funnel-shaped flowers. This week’s blog will focus exclusively on Rhodies. I’ll discuss Azaleas in the next blog.

Growing Rhodies in the hot, humid southeast can be a challenge. One gardener told me the secret to her success: “Plant it low and it won’t grow. Plant it high and it won’t die.” She planted her Rhodies by placing the rootball in a shallow depression, piling a 4-inch volcano of loose mulch on top, and watering abundantly. Rhodies need acid soil with a high humus content and moist but well-drained soil. They absorb water through their leaves as well as their roots, so they prefer overhead irrigation. Take care to soak the entire root zone. This is one shrub that does not perform well with soaker hoses or drip irrigation since the root zone is not uniformly dampened. Water in the morning so that leaves are dry before temperatures drop at day’s end. This will help to prevent fungal diseases.

Rhodies hate heavy clay soils, so amend the planting area with ground bark or peat moss or both. Partial shade or filtered sun is best. They have an affinity for the shade cast by tall pine trees. Too much sun bleaches and crisps the leaves; too much shade means few or no flowers. Avoid planting in windy areas. Fertilizer is rarely needed unless one wants to increase the growth rate. Any fertilizing should be done after blooms fade, using a product that is labeled “for acid-loving plants” like camellias, gardenias, hollies, and hydrangeas. Use particular care in removing weeds, since Rhodie roots are shallow and resent damage from cultivation. Limit pruning to the removal of spent flower heads. Such removal will prevent the plant from trying to form seeds and will result in a stronger plant. A gangly plant can be made more attractive by pinching the growing tips of limbs to force branching.

In the warm southeast, search for heat-tolerant cultivars like ‘English Roseum (light rose flowers), ‘Roseum Elegans’ (lavender pink flowers) and ‘Nova Zembla’ (red to dark pink flowers). These will range in height from six to ten feet at maturity, with an equal spread.

All parts of the plant are highly toxic to humans and pets.

I inherited this Rhodie with the property we bought, so I don’t know the variety. I love her freckles.

The leaves of this Rhodie are not diseased; they are covered with pollen shed by the oaks and pines overhead.

Sturdy Spireas for Spring Color

Spirea was one of the first shrubs whose name I learned as a child. There was an enormous plant next to our kitchen door. In early spring, it was covered with clusters of white blooms on arching stems. It had almost no scent, but the flowers were impressive although short-lived. When I asked my mother what kind of “bush” it was, she told me (semi-accurately) that it was a Spirea Van Hootie. Now I know that it was a Spirea x vanhouttei. Moving to the front garden, I asked her for the name of a shorter shrub with deep pink blooms.“Spirea,” she responded. “How can this be Spirea if the other one is Spirea,” my six-year-old self inquired, “because they’re not the same color and they’re not the same size and they don’t look alike.” Her response: “Go ask your father.” (A lot of our conversations ended this way.) As an adult, I realize the smaller, pink-flowered cultivar was ‘Anthony Waterer,’ one of the oldest and still one of the most tolerant of heat, poor soil, and bad pruning.

As a genus, Spireas are hardy and long lived. There are numerous species, and new cultivars seem to arrive on market every year. Sizes range from tiny to giant; flower colors can be pink, white, or red, and can occur on branch tips or all along the stems. Old varieties have narrow blue-green leaves that neither impress nor disappoint. Some of the newer cultivars have brightly colored foliage which extends the beauty season beyond the bloom period. In the Mary Snoddy garden, a pair of Spirea japonica ‘Limemound’ throw bright yellow foliage in early spring, which darkens to a lime green when weather turns hot. Limemound has bright pink flowers that scream for attention against the yellow foliage. Viewers either ooh and ahh or walk away muttering something that might be “eyesore.” The Limemound’s foliage turns orange in autumn and then sheds entirely, leaving a winter framework that resembles a jumbled ball of sticks. I underestimated the mature size of these shrubs (three feet with an equal spread), so I am forced to prune hard every winter to keep them within the bounds of available space. This major pruning has no evident impact on the plants’ health.

Among the white-flowered variety, Spirea nipponica ‘Snowmound’ is a 3–5-foot shrub that looks like a fireworks display when in bloom. If you have space, old Van Hootie, Spirea vanhouteii will grow to ten feet tall and twelve feet wide. Nurseries may label the vanhouteii species as “Bridal Veil” or “Bridal Wreath” Spirea, but these terms are also used in marketing Spirea prunifolia and Spirea cantoniensis, similar but smaller in stature.

Spireas bloom heaviest on young stems, so pruning will force new growth and result in more flowers the following year. Pruning should be done as soon as the flowers fade and fall. Cut stems to varying lengths with hand pruners rather than using hedge trimmers to create a round ball. Plants are most attractive when one-third of the oldest branches are cut back hard and the remainder are pruned lightly. This maintains their graceful arching appearance. These shrubs look best when grown in groups or hedges rather than as single specimens. They perform well on slopes where mowing is treacherous.

Spireas tolerate most soil types and will withstand half-day shade, although flowering is better in full sun. Avoid wet sites. Most species are cold hardy zones 5-9 or even colder, but check the plant tag to confirm zone for your selection. They are rarely bothered by diseases, insects, or deer.

Spirea japonica ‘Limemound’ elicits comments that range from “Outstanding” to “Yikes!”

A close view of Spirea cantoniensis ‘Reevesiana’ flowers

A young planting of Spirea cantoniensis ‘Reevesiana,’ perfectly sited at the top of a steep bank near a creek.

Wonderful Weigela

Weigela is one of those shrubs that puts on a heart-stopping bloom display in the spring, then fades into obscurity the rest of the year. Mature shrub sizes vary from two feet to ten feet. They don’t mind acidic clay soil, and will tolerate limited drought once established. They prefer morning sun and afternoon shade. Weigela florida sounds like they are Florida natives, but they hale from Japan, Korea and North China.

Most funnel-shaped flowers are white or pink with a darker pink reverse. The blooms occur the entire length of the stem, so the pink buds are seen along with the white blooms. I have seen true red and purple varieties offered in catalogs, but have not found them in local nurseries. All colors are loved by hummingbirds and bumblebees. One of my favorites is ‘Variegata,’ which has white edged leaves, making it pretty even when not in bloom. ‘Wine and Roses’ cultivar has a burgundy leaf and a dark pink bloom. ‘My Monet’ has variegated pink and white leaves, pink blooms, and is dwarf (no more than two feet tall) which makes it easy to incorporate into a mixed border.

This deciduous shrub is round and somewhat loose. There is no fall color. The branches of a mature specimen arch similar to Forsythia. Through experimentation in the Mary Snoddy garden, I have found that the shrub looks best if about one-third of the branches are cut back hard (half their original length) immediately after bloom. This forces new growth. Heaviest blooms occur on the youngest stems. I follow the hard pruning with an overall shaping, to restrict size. If pruning is done mid-summer or later, there will be little to no bloom the following spring.

Weigela grows in zone 4 to 8. The further south, the greater the need for a little shade during the hottest part of the day. Deer think they are delicious, so site them away from easily accessed areas. (We all know that deer will take a bus and climb a ladder to reach something they find tasty.)

The name is pronounced wye-JEE-lah. There is not an “i” in the last syllable, so it is not wye-JEEL-yah.