Have we finally found Mrs. Calabash?

Students of television history know that entertainer Jimmy Durante closed his weekly variety program with the cryptic message, “Good night, Mrs. Calabash, wherever you are.” Theories abounded as to whom, or what, the salutation applied. Durante’s first wife? A restaurant in North Carolina? An old flame?

We at Richard Lyons’ Nursery are sad to report that, despite exhaustive research by our Trivia Department, we don’t have a clue as to the true identity of Mrs. Calabash, but we do know about the Calabash Tree, and we think you should, too.

Known botanically as Crescentia cujete, the Calabash Tree is native to lowland habitats of Central and South America, but has been cultivated around the New World tropics for thousands of years. It is now grown in tropical lands worldwide. Its popularity is owed to a couple of features. First, it is ornamentally interesting. It produces flowers directly on the plant’s stems, a trait known as cauliflory. The gourd-like, nearly round fruits that follow can reach about a foot in diameter. While developing, the fruits are soft and can be coaxed into unusual forms, but eventually they develop a hard, thin shell.

The Calabash Tree grows slowly and may eventually reach 20-30 ft. in our region. It features long, spreading branches that, combined with the plant’s cauliflory, impart a distinctive, easy-recognizable appearance. As an added attraction, the tree’s rough bark makes it ideal for supporting epiphytes, including bromeliads, orchids and ferns.

Another feature accounting for the popularity of C. cujete is its utility to humans. For example, the mature fruits are made into bowls, cups, and rattles, and larger shells tend to be used as storage containers. The tree’s wood is sufficiently dense to be incorporated into tools, stirrups, and vehicle parts, and it has some construction applications.

The calabash also has a role in folk medicine. It is said that various plant parts are processed to treat headaches, colds, pneumonia, intestinal woes, asthma, wounds, and toothaches.

Homeowners will find this species easy to grow. It prefers a sunny exposure and ample water. It is not particular about soil type––the alkaline soils of our region are no challenge––provided that there is good drainage. Richard Lyons’ Nursery grows these trees in 15-gal. containers.

By the way, C. cujete has hermaphroditic flowers, so it is at least conceivable that it could have produced either a Mrs. Calabash or a Mr. Calabash. Durante probably didn’t know that.

Let’s Get Back to Basics

As you know, April is one of the most stressful months on the calendar, and it has nothing to do with the dreaded income tax deadline. Homeowners in southern Florida also need to worry about the cumulative effects of the long dry season. In a normal winter, April is not only mostly sunny, but also windy and increasingly warm. That combination puts a premium on diligence in caring for plants in containers and in the ground. A few days of inattention can have detrimental––and even lethal––effects on plants in the landscape.

Unfortunately, the early months of 2018 have been even drier than normal for most of our region. Through April 12, rainfall at the international airports in Miami-Dade and Broward counties is 5½ and 6½ in., respectively, below average for the year.

Since many plants have already resumed active growth, now is the time to start preparing for the summer months. With the rainy season still about five weeks away, it is especially important to keep plants well-irrigated. Even the occasional rain shower may not be enough to hydrate thirsty shrubs and trees. Be sure to water inground plants thoroughly so that moisture reaches deeper parts of the root system.

The next concern is fertilization. With the risk of frost long-past, now is the time to make the first application of the year. Be sure to use the product in accordance with label instructions. Do not succumb to the notion that if a little fertilizer is good, a lot is even better. The salts inherent in the chemical compounds of commercial fertilizers can kill, or at least burn, shrubs or trees if applied in excess.

The choice of fertilizer formulations is also important. Since the soils of southern Florida are mostly bereft of important nutrients, it is beneficial to use a fertilizer that contains a variety of elements. A good palm special fertilizer will fill that need for a wide array of plant species. To see what you’re getting, be sure to read the guaranteed analysis that, by law, must appear on every bag of fertilizer. Beneath the major elements––nitrogen (N), phosphorous (P), and potassium (K)––is a list of other elements present in trace amounts.

Richard Lyons’ Nursery recommends that homeowners apply fertilizer 2-3 times a year. If you choose two treatments, do the first now and the second in September. If you prefer to make three applications, do the first now, the second in June or July, and the third in September or October.

There are several important caveats to observe in fertilizing your plants: (1) Avoid application during cold weather. Generally, when soil is cold, the ability of roots to take up nutrients is greatly diminished. However, a nutritional spray can be used at any time of year, since it is applied to the undersides of leaves and therefore bypasses roots. (2) Distribute fertilizer evenly over the root system of the plant. For trees, the key area is that lying within the edges of the canopy. Leaving little piles of fertilizer can burn roots. (3) Make sure that soil is moist before applying fertilizer, and then water the product in afterward. (4) Do not use fertilizers intended for inground plants on containerized plants; their formulations tend to be too strong.

Shrubbery Recommendations for Screening

With winter quickly receding into the background, we turn our attention to a subject of perennial interest: how to develop foliar barriers. You may want to cover up a fence or a building, create the illusion of size by installing circuitous pathways, or simply enhance privacy. In our subtropical world, there are many species that help achieve those goals. Here’s a survey of a just a few of the choices available for those purposes at Richard Lyons’ Nursery.

Hamelia patens (Firebush): H. patens is a native shrub that is remarkably amenable to various soil types, from the alkaline rockland of southern Florida to the deep acidic soils of the temperate South. It flowers best in full sun, but performs well even in some shade. The species is reasonably drought-tolerant, but can handle plenty of water, so long as good drainage is ensured. Once established, it is quite easy to maintain; cutting it back periodically will promote compactness and encourage blooming. And it doesn’t even require much fertilizer!

Firebush has a huge native range, from north central Florida and Bermuda in the north through the Caribbean, Mexico, Central America, and into Paraguay in the south. In southern Florida it is a semi-woody evergreen shrub or small tree that reaches about 12 ft. high. Its leaves are oval to elliptical, up to 6 in. long, featuring reddish veins and leafstems. It produces clusters of ¾-in. red-orange or scarlet tubular flowers throughout the year. Its berries are also attractive, developing through a range of colors from green to yellow to red to glossy black. In the ground, Hamelia can be used as a solid hedge or can be mixed with other materials, but it can also be featured to great advantage as a stand-alone specimen. It is quite popular in hummingbird and butterfly gardens. In colder locations that experience a distinct winter, Firebush makes an outstanding container plant that can be brought indoors and kept in a bright location until the return of warm weather.

Jasminum sambac (Arabian Jasmine): This popular species, while native to a confined region of the eastern Himalayas, has become naturalized in many places around the world, due largely to its very nice fragrance. In fact, the flowers are the source of an oil which is incorporated in perfumes and Jasmine tea. Somewhere along the way it took on the common name Arabian Jasmine, but that is misleading, since it does not like arid climates. It grows as a small, informal shrub or vine, with glossy, dark green leaves, and matures somewhere between 1½ and 10 ft. in height. It bears sweet-smelling waxy white flowers about an inch across. The cultivar ‘Grand Duke of Tuscany’ is especially appealing, since its blossoms grow as doubles which resemble miniature gardenias.

J. sambac performs well in sunny to partially-shaded exposures. It likes abundant water, provided that there is also good drainage. Once cooler weather arrives, its moisture requirements diminish.

Aloysia virgata (Sweet Almond): Plant lovers appreciate the vast array of fragrances encountered in tropical and subtropical species. One of the best of them introduced to our region is the Sweet Almond, Aloysia virgata. Its strong fragrance is optimally enjoyed at a distance from the plant, where breezes easily carry it. Native to fairly dry subtropical areas of Argentina, Sweet Almond can be grown in the ground all the way into Climate Zone 8, where it is treated as a perennial. But in southern Florida, it is an evergreen capable of reaching 15 ft. in height. It has an upright, informal habit with some horizontal branching, and is amenable to hard pruning for owners preferring to maintain it as a shorter shrub.

A. virgata blooms in flushes on and off most of the year with spikes of tiny white flowers. The leaves are dark green to gray-green and feel sandpapery to the touch. Happily, the plant is not very demanding. It tolerates average soils and, once established, is sufficiently drought-tolerant to perform well in a xeriscape. Sweet Almond provides more than just an appealing fragrance, as it also attracts bees and butterflies. In particular, it is popular with the Atala Butterfly, Eumaeus atala, which is still in recovery from near-extinction.

Bougainvillea spp. (Bougainvillea): Maybe you’ve noticed lately that knowing what is true has become rather elusive. For instance, can both of the following statements be true? (1) Bougainvillea is one of the most colorful vines in the world. (2) The flowers of Bougainvillea are small and inconspicuous. The answer is yes. That’s because the features that produce the spectacular colors found in this genus are actually bracts, modified leaves located at the point from which flowers develop. Thus bracts are an integral part of the flowering process, though they are not flowers themselves.

There are over 300 cultivars (cultivated varieties) of Bougainvillea! Plants produce sprawling, arching branches, but can be trained to grow as a standard. Often used in the ground as an impenetrable screening material, it can also be grown in containers or hanging baskets where pruning following bloom will keep the plant compact and encourage side-branching. And as a container specimen, Bougainvillea is particularly amenable to thriving on high-rise balconies, because it is very resistant to winds. Although not extremely cold-hardy, the genus can stand enough frost to be widely grown as an ornamental in southern Switzerland near the foot of the Alps.

The best color production occurs in full sun. The genus is highly salt-tolerant, so coastal exposures are no problem. Bougainvillea is also quite drought-tolerant, and once a plant installed in the ground becomes acclimated, it will require little supplemental watering. In fact, the very rainy and hot summers of southern Florida inhibit color displays, so in our region Bougainvillea flourishes best during the dry season. It responds well to light applications of fertilizers, but use of a high-nitrogen formula will produce rampant vegetative growth without much color. A balanced formula is a better bet, and some experts recommend fertilizers formulated for roses or other flowering plants.

The cultivar ‘Pixie’ deserves special mention. Not only is it almost thornless, but it also produces color later into the summer than many other cultivars.

Thunbergia erecta (Bush Clock Vine or King’s Mantle): Here is yet another plant recommendation that adds color on the purple and white side of the palette to the parts of your garden where lighting is muted. Thunbergia erecta, a native of western Africa, is a woody shrub that reaches about 6 ft. high and wide, bearing small glossy green leaves.  It produces tubular yellow-throated, deep purple flowers 2-3 in. across which may appear singly or in clusters. There is also a white flowering cultivar with similar growth habits as the purple variety.  In addition to their beauty, the blooms are also mildly fragrant. Flowering occurs throughout the year, but most profusely in the summer months.

The fast-growing Bush Clock Vine—‘vine’ being a misnomer borrowed from this species’ climbing relatives—makes an outstanding hedge for foundation plantings or borders. Left to its own devices, it will develop a sprawling habit, but it is very amenable to pruning. This desirable plant is also seldom affected by insect pests.

Myrcianthes fragrans (Simpson’s Stopper): This species commemorates Charles Torrey Simpson, botanist, conservationist and Sage of Biscayne Bay, for whom Simpson Park just south of downtown Miami is also named. Its species name refers to the sweet aroma of the flowers, but the leaves also produce an aromatic smell when crushed. This stopper grows as a large shrub or small- to medium-sized tree with reddish peeling bark. It usually matures in the 10-20 ft. range, but 50 ft. is not unheard of in southern Florida. The growth rate is slow to moderate.

M. fragrans is native from Lee, Okeechobee and St. Johns Counties southward through the Keys and into the West Indies, Mexico, Central America and South America. Leaves are 1-2½ in. long and semi-glossy on the upper surface. Dots on the leaf surfaces contain the aromatic substances which are released when the leaves are crushed. Simpson’s Stopper produces clusters of white flowers year-round, but most heavily during the spring and summer. The flowers are followed by orange to red globose berries that provide a food source to a variety of wildlife.

The species is native to moist, well-drained limestone or sandy soils. Like the other stoppers, it does not like long exposures to salt air or salty or brackish water. Drought tolerance is moderate once a plant is established in a new site. For best results, grow Simpson’s Stopper in full sun to light shade.

Polyalthia longifolia (Mast Tree)

About 40 years ago, a Miami couple fresh from a long trip to Asia brought seeds of an attractive Indian evergreen tree to Fairchild Tropical Garden. Over time this species, Polyalthia longifolia (a/k/a P. longifolia var. pendula), has proven to be a very successful introduction to the landscape of southern Florida. Commonly known as the Mast Tree––ship masts are among the products manufactured from its wood––it is pyramidal, or spindle-shaped, and capable of reaching 30+ ft. in height. It features long drooping branches and dark green, lance-shaped, glossy leaves with undulating margins.

Polyalthia provides an excellent alternative to Italian Cypress, which in southern Florida is prone to spider mites and fungal disorders. Another advantage of the Mast Tree is its cleanliness; it does not shed. Needing light pruning just every 1-3 years, this species fits the definition of low-maintenance. Not surprisingly, P. longifolia trees in southern Florida have recovered well from Hurricane Irma.

The Mast Tree is classified in the same family as Ylang-Ylang, Custard Apple and Soursop, which were introduced to our area much earlier.

In the landscape of bustling Asian cities, the Mast Tree is often used to soften noise. Aside from its ornamental appeal, Polyalthia is said to contain medicinal properties. (In fact, the genus name itself is derived from the Greek words for ‘many cures.’) Studies reputedly confirm antifungal and antibacterial capacities, as well as usefulness in combating ulcers, fever, hypertension, diabetes, and certain cancers. At Richard Lyons’ Nursery, these handsome trees are available in 3-, 7- and 15-gal. sizes.

Our Trees Six Months After Hurricane Irma

It’s a little bit hard to believe that Hurricane Irma occurred six months ago. Many trees in southern Florida, including some in the ground at Richard Lyons’ Nursery, took a walloping thanks to a number of factors previously addressed in this space (see “Lessons Learned from Irma,” September 30, 2017). Now, half a year later, the bad news is that if you have not staked up a downed tree, it is too late. But there’s also good news: You still may be able to salvage the tree.

Provided that your toppled tree remains partially rooted, the first step in attempting to save it is to cover any exposed roots with soil. Then prune the tree back to a much shorter height. Even without a full root system, the tree may leaf out and, over time, develop new stems. Since sprouting may take until May or June to begin, do not be in a hurry to dig up a tree that appears dead.

While waiting for the tree to begin showing signs of recovery, make sure to provide regular watering. After some time has elapsed, you can select the most vigorous and upright of the stems to become the new trunk of the tree. However, you may still want to leave some of the formerly upright, but now supine, branches in place to contribute to the new, unusual – and perhaps even artistic – shape of the tree.

As we head into warmer weather, it would be helpful to fertilize your storm-damaged trees lightly to promote more vigorous growth. As is always true when applying fertilizer, water it in well. A palm special fertilizer is recommended, because the better formulations contain a number of elements in trace quantities that benefit trees and other plants growing in our nutrient-poor soils.