Some Ideas on Gardening in Southern Florida

The winter issue of the Miami-Dade Extension Connection, a newsletter published by the county’s extension office (IFAS), contains an informative article titled “Easy Ways to Grow Vegetables.” Since mid-winter is a great time to cultivate a home vegetable garden, Richard Lyons’ Nursery would like to direct your attention to setting up the garden for maximum satisfaction. It’s essential to understand that the ‘easy’ part of the process really refers to the relatively carefree approach a grower can take with many vegetable species after preparing the planting site. But getting the planting space ready for the season requires some exertion.

For growers with limited room in which to do their gardening, the most important advice offered in the IFAS article is not to plant and cultivate vegetables in rows, because that method “wastes space and provides more opportunities for weeds.” The article mentions square foot gardening (SFG) and the French intensive method (FIM) as alternatives to row planting. They are not identical, but what they have in common is that they conserve space and can increase the crop yield. In square foot gardening, a technique that’s been around since the early 1980s, the plot is divided into squares, either literally 12 in. by 12 in., or somewhat smaller or larger. Each square can be used for a different vegetable species, and, depending on mature size, a given square will contain one or more plants. The method has been refined in the last 12 years. Now the recommendation is to plant on raised beds that substitute a blend of compost, peat moss and vermiculite for topsoil, an approach that short-circuits the time-consuming need to improve the soil.

The much older French intensive method of gardening involves improving the soil itself instead of overlaying it with a blended potting medium, and accordingly is more labor-intensive and time consuming. The process requires double-digging: Ideally, the topsoil is augmented with manure or other nutrient source, then dug out to create a trench 12 in. deep. The excavated topsoil is kept nearby for later use. The trench is then turned 12 in. deeper by shovel or fork. The gardener repeats the process adjacent to the first trench. The topsoil/nutrient mix excavated from the second trench is used to fill the first. The final trench is filled by the topsoil conserved from the first trench. Because the topsoil and the underlying soil have been broken up in the digging process, the trenched planting beds will tend to be higher than the surrounding untreated ground. The double-digging can be repeated from time to time over a period of years, so that the soil being farmed is slowly improved.

But the French intensive method, in its strictest definition, is hard to implement in southern Florida. In those parts of the region underlain by limestone, it is daunting, if not impossible, for a home gardener to hand-excavate a trench 24 in. deep. And where the soil is sandy instead of rocky, the sparse natural organic matter exposed by digging can quickly dissipate from heat and wind action.

According, what the IFAS article recommends most closely matches square foot gardening. It calls for creating a raised bed on a site that receives at least seven hours of full sun daily and then installing a compost-potting soil blend. The topsoil is not used in the composition of the bed and thus doesn’t need to go through the lengthy improvement regime. The raised-bed technique enhances drainage, and the proximity of the plants to one another tends to discourage the growth of weeds.

After the labor of creating the planting site is completed, home gardening can be fairly uncomplicated. IFAS describes the following dozen crops as easy to grow: Beans (bush or pole), broccoli, carrots, collards, kale, leaf lettuce, onions (green), peppers (sweet or hot), spinach, sweet potato/boniato, and tomatoes. Richard Lyons’ Nursery would like to supplement that list with the following recommendations: Beets, cabbage, celery, eggplant, herbs (oregano, parsley, thyme), kohlrabi, leeks, peas, radishes (including Daikon), Swiss chard, and tomatillos.

For more information on this and related topics, open the following link: http://miami-dade.ifas.ufl.edu/lawn_and_garden/home_gardening.shtml

Good gardening!

 

Firespike (Odontonema strictum)

Firespike can really fool you. You might think that a plant native to Central America would perform poorly in cold weather, but this species is capable of doing quite well along a huge swath of the U.S. running almost uninterrupted from southern South Carolina to southern Washington. And it’s beautiful to boot!

This evergreen shrub, known botanically as Odontonema strictum, bears stiff, mostly upright, sparse branches that reach about 6 ft. in height. Its dark, shiny, oblong leaves are pinnate, measuring 4-6 in. in length. Its native habitat is semi-forested, and so it comes as no great surprise that Firespike has become naturalized in disturbed hammocks around peninsular Florida. In the coldest places where it is found in the U.S., it dies back to the ground in the winter, but in southern Florida, it grows as an evergreen semi-woody shrub. This species thrives in moist soils, but they should be well-drained. It can tolerate considerable drought, and in residential settings, watering can be reduced during the winter. It is not particularly salt-tolerant.

As presentable as it is out of flower, Firespike is really impressive in bloom. Starting in late summer and extending through the winter, it produces numerous upright 9-12 in. panicles featuring inch-long, tubular, waxy, brilliant red/scarlet, purple, or lavender flowers. (It should be noted that many botanists consider the purple variety to be a separate species, O. callistachyum.) Although it is at its best in full sun, O. strictum can still put on quite a show in filtered light. The combination of bright flowers and glossy leaves is eye-catching, especially at the time of year when blooming peaks. It is particularly effective in mass plantings.

Firespike is not only good-looking, but it also attracts hummingbirds and butterflies. The plant spreads underground, but can also be propagated easily from softwood cuttings that will flower in their first year. O. strictum is also very amenable to pruning. You can either cut it back hard or prune it lightly several times during the year to maintain the look that you prefer. This desirable shrub is available at Richard Lyons’ Nursery in 3-gal. containers.

Odontonema callistachyum (Purple Firespike)

Odontonema callistachyum (Purple Firespike)

Odontonema callistachyum (Purple Firespike)

Odontonema strictum (Red Firespike)

Odontonema strictum (Lavender Firespike)

A Few Words on Dealing with Winter Weather

Judging from some of the recent news headlines, one might get the impression that southern Florida is setting records for cold weather. Nothing could be further from the truth. The winter of 2009-2010 was the coldest since 1940, and there was another cold outbreak in December 2010, but since then we have had unusually warm winter seasons.

Reaction to cold nights around the middle of December 2017 and again during the first week of the new year has been a little bit frantic in some quarters, but the truth is that we simply have become spoiled by our abnormally warm recent winters. Low temperatures in southern Florida this winter have come nowhere near record readings. Nevertheless, there has already been enough cold weather in 2017-2018 to cause damage to tropical plants, and additional cold weather is likely to invade our area from time to time over the next couple of months. Accordingly, the staff at Richard Lyons’ Nursery wishes to address the subject of dealing with the effects of cold weather on our tropical plants.

In deciding what to do to protect plants from cold weather, you should first become acquainted with the cold-hardiness of each of your species. If you didn’t ask the seller at the time you bought the plant, then talk to neighbors or friends who have grown the species that you have. That approach avails you of people’s experience locally. But you can also supplement their input by way of an Internet search for the plant name along with a term such as ‘cold-hardiness.’ The steps you take to learn the cold tolerance of each of your species will allow you to rank the relative sensitivity of your plants and help you avoid wasting time on those that don’t need special care.

Next, pay attention to the details of the forecast. Frost can cause the fluids within plant cells to expand and rupture cell walls. A breezy night can be protective, because it prevents the formation of frost on leaf surfaces. However, at some level of intensity, winds can themselves cause damage; accompanied by low humidity, they can desiccate leaves. On the other hand, if winds are expected to be calm, it is possible for frost to form at a temperature above 32 degrees, particularly if the humidity is high. (Following passage of the cold front in mid-December 2017, even though lows in urban areas were in the 40s, temperatures in parts of the farming area dropped to 36 degrees, with frost.) It is not uncommon even on a breezy night for winds to cease right before dawn, and that can be devastating, because just a few minutes of calm can allow the formation of damaging frost.

On the rare nights when a freeze is expected in our region, the duration of temperatures under 32 degrees become important for the well-being of those plants which have enough hardiness to tolerate some frost. Consider citrus, for example. The trees themselves can handle considerable cold, but their fruit is less hardy. Cold can be both beneficial and detrimental to fruit. A certain amount of chill will cause it to sweeten, but if subfreezing temperatures persist for more than six hours, fruit cells begin to sustain damage.

Once you know the relative cold-hardiness of the plants in your possession, you can take steps to prevent, or at least minimize, damage. Obviously, you will have more choices at your disposal if you are dealing with containerized plants, at least those small enough to be moved. An easy and effective tactic is to relocate them beneath the cover of a large, dense-canopied tree. The tree’s crown keeps heat that is stored in the soil from radiating away as quickly as it would from open locations. Just a few degrees’ worth of extra warmth may be enough to protect your plant. If your containerized plants are too heavy to move, you may nevertheless possess a slight advantage if they are on higher ground on your property, since cold air drains to the lowest spots as it invades an area. In pancake-flat southern Florida, ‘higher ground’ is a fairly subtle concept, so even if you have placed your large containers in sites that are only a foot or two above the surrounding soil, that can help them escape the worst damage.

You may also put a cover over a plant, but be aware of the limitations. A cloth cover can help a bit, but it permits heat loss through the fabric. A plastic cover can be more effective, but you must avoid allowing it to come into contact with plant surfaces, since the plastic will act as a conductor of cold into the plant. If sub-freezing temperatures are predicted and your containerized plants are too numerous to move, you can employ the technique used by vegetable farmers: Icing. A layer of ice applied by a sprinkler can protect plant surfaces from the worst effects of cold. However, if you opt to go that route, you must be sure not to turn off the water too early. The best policy is to continue watering until the sun is high enough in the sky to melt the ice from plant surfaces.

Finally, you should give some consideration to what remedies to undertake following a damaging cold event. In most instances, the best approach is to assess the damage, but do nothing initially. In particular, don’t prune dead leaves from shrubs or trees; they tend to insulate the plant from further problems in any subsequent cold weather outbreaks, Wait until the chance of frost for the season is safely past. By that time, the plant may generate new growth that provides you the perfect natural indicator of where to prune away dead material.

Even if your plant exhibits no outward signs of cold damage, don’t assume that it came through unscathed. Palms in particular may look fine even though they have suffered internal damage to the bud that may lead to the plant’s death months later. To be on the safe side if you own a species known to be cold-sensitive, pour or spray a fungicide (diluted according to label instructions) directly into the bud at the spot where new leaves emerge, and administer a second dose 7-10 days later. Alternatively, you may apply 3% hydrogen peroxide, the strength found in drugstore formulations, into the bud. But avoid the temptation to treat your palm with both types of chemicals; they are not compatible.

Maintain standard watering habits. While periods of rainy weather may relieve you of the need to provide supplemental water, you should stay alert for the sudden onset of dry weather that requires intervention on your part.

Tropical Bonsai

When you hear the word ‘Bonsai’, you usually think of temperate zone conifers, Japanese maples, and other assorted deciduous trees.  However, in South Florida, ‘Bonsai’ takes on a whole new connotation.  The choices for plant material are almost endless.  There are our natives to choose from, such as the Stoppers, Lignum-vitae, or Christmasberry to name a few.  Then there are tropical fruit trees, like Jaboticaba, Barbados Cherry, and Cherry of the Rio Grande.  Oh yes, the biggest category of all, the ornamentals with such standbys as Bougainvillea, Ficus neriifolia, and Tropical Dwarf Holly (Malpighia coccigera).  Of course, we too have our conifers, although most of them are of a tropical nature, bonsai enthusiasts have grown them into nice specimens for years.

If you are an experienced grower, or just want to get started, Richard Lyons’ Nursery has plenty of the plant material available to get you started.

Palms for Autumn Planting, Part V

The survey of palm species available at Richard Lyons’ Nursery in 3-gal. containers concludes this week:

Dictyosperma album var. album is commonly known as the Princess or Hurricance Palm. It is a pinnate, self-cleaning palm that features a yard-tall, waxy crownshaft. Endemic to the Mascarene Islands in the Indian Ocean, it is reported to be nearly extinct in the wild due to farming activities. In southern Florida, this water-loving species matures to about 30 ft. and performs best in a sunny site. It is more capable of tolerating a cold night followed by a rapid warmup than sustained periods of cool weather.

Licuala grandis, the Ruffled Fan Palm, is native to Vanuatu and the Solomon Islands. It is a striking small species featuring nearly circular leaves that look as if they’ve been cut out by pinking shears. Best grown in shade when young, L. grandis tolerates more sun later. Given generous irrigation, it will reach 15 ft. slowly in southern Florida. Because it does not have an aggressive root system, it can be maintained successfully in a container, particularly if a saucer is placed underneath it to hold water.

Syagrus botryophora, known as the Pati Queen Palm, is a fast-growing species endemic to the coastal woodland of Brazil. It has a thinner trunk than the standard Queen Palm (Syagus romanzoffiana). Its crown contains graceful recurved leaves with ascending, or V-shaped, leaflets. Rainfall in its native range is even throughout the year, so irrigation during the southern Florida dry season is a must. It matures to somewhere in the 20-50 ft. range, and responds well to nutrition that includes minor elements. Plant in full sun.

Thrinax radiata, the Florida Thatch Palm, is native from southern Florida into the Bahamas, the Caribbean, the Yucatan Peninsula, and Central America. Its palmate leaves are dark green on top, light green beneath. Pea-sized fruits ripen from green to white. Inground plantings mature to 30 ft. after many years. It is also recommended for both small yards and container culture. T. radiata is best grown in full sun to light or high shade. It is tolerant of winds, salt, drought and poor soils.

The series concludes with some recommendations on planting these palms in the ground, advice reinforced by our recent hurricane experience: Do not skimp on preparing a planting hole. Particularly in areas where limestone is near the surface, dig a large hole so that root system growth over the years will not be inhibited by the rock. However, it is better to refill the excavated hole with the broken pieces of limestone than to introduce a richer planting medium. The material within the planting hole should not be better than the surrounding soil, even if it is not highly nutritional. Nutrition can be provided through sound fertilizing and mulching practices.