March 30, 2011

My Potted Plants are Dying ! Now What ?

If you have ever grown more than a few potted plants at one time, you will have experienced the drama of seeing your plants fail. This is usually accompanied by dropping leaves, wilted stems, and occasionally some seriously bad odors. There are myriad reasons why plants fail, but in the vast majority of cases, the problem is your fault. There are innumerable reasons why plant failure is your fault, too many to list, but let's make sure you realize the problems had to do with you, and I'll list some of the main reasons why.

  1. Hands down, the major reason for plant failure is improper watering. There is an old sage about killing plants with too much water, but this is a misnomer. "Improper" watering is more accurate, since a common scenario is to see a plant wilting due to drought, then water it too much, causing a root rot. The question would then be: did the plant die of too little, or too much water ? The answer would be"both". 
  2. One of the most frequent reasons for plant failure is a poorly chosen potting mix, or a soil medium that has decomposed. In either case, the roots of a plant are suffocating, and the plant will look weak, dried out, and "tired". 
  3. It is also common that people will place an indoor plant into a pot that has no drainage hole in it. This is a great way to suffocate a plant if you over-water the plant. I have seen plants in interior plantings that were literally floating in water due to a kind hearted person who kept watering a failing plant, thinking it was thirsty. If you do use a sealed container, plan to place drainage material in the bottom of the pot, such as broken pot chips, gravel, styrofoam peanuts, hardwood charcoal, or a similar inert material to prevent the plant's roots from sitting in wet soil at the bottom of the pot. Plan for about 1/3 of the height of the pot to be used as drainage. 

Once you discern that the plant is failing, then you need to figure out how to repair it. This is usually  a matter of repotting the plant into fresh soil, removing the dying plant parts, and renovating your growing methods to avoid a recurrence of the problem. If you repot plants every year when the plants start to grow, you'll find that the problems of poor quality soil, rotted roots, and slow growth usually go away. In the case of orchids and bromeliads, annual repotting is a must. In these cases, removing dead roots and repotting into fresh media is key to their survival. Especially in areas with municipal water or well water, the buildup of fertilizer and calcium salts is profound, and will lead to plant failure.

One critical thing to remember is that root rots are caused by a group of fungi called water molds, and are treated with systemic fungicides specific to root rots. The vast majority of fungicides available at retail vendors are for leafspotting  fungi such as black spot or anthracnose. The difference between leaf spotting fungi and root rots is the difference between acne and smallpox; the treatments and cures are quite different ! 

The moral of this story is to watch your plants carefully. If the plants are indoors, they will need watering differently than those that are outdoors exposed to wind, heat and sunlight. Even in near-perfect ouitdoor conditions, plant roots are still confined or imprisoned in a pot, and not allowed to grow out into the drainage of native soil. Keep this "root prison" concept in mind when you decide to overfertilize and overwater. The concept is a good one, especially for those plants used to growing on trees and rocks in their native habitat !

Craig Morell
Pinecrest Gardens        

March 23, 2011

Spring Flowers- Part 1-  Periwinkle ( Vinca)

Every year in Miami, Spring sneaks up on us. The official date is on the calendar, but we are caught by surprise every March or April. I hear the same comments about the heat every year. I hear myself saying the same thing: " it's getting hot really fast", and "wow, that afternoon sun is really intense". This increasingly intense sun also leads to some drought problems, and we seem equally surprised that we have to water our Impatiens or Pentas more often. The Impatiens in particular are looking tired, beginning to get thin, and need more fertilizer than just a month ago. Many other annuals wilt every afternoon, since the sun if getting higher in the sky, and the early Summer rain is still a month away or more. The "mean season" of late March through the first week of May results in bleached plants, sunburned gardeners, and frazzled nerves. What can we do to relieve these problems, and are there really better plants to use as annuals ? There are many answers, and they can help make your garden a much easier place to work in. 

"wild" type Periwinkle

Consider that in most parts of the country, water is getting scarcer. Although there may be some very rainy periods and even flooding, the overall availability of ground water is getting worse and worse. We should look at water saving techniques in every venue of gardening, as well as every other venue in our daily lives. Let's look at one variety of annual that likes drier soil conditions than, say, and Impatiens, the gold standard of annuals. In many parts of South Florida, we see the wild Madagascar Periwinkle, a cheery little plant that pops up in dry parking lots, rock piles, and unexpectedly on rooftops. One would think that someone would harvest the seed from it, grow it, and make a lot of money by selling a totally drought tolerant plant, but the plant is rather fussy to grow commercially; it hates being potted, and is none too fond of being watered as are many annuals in commercial production.

There are numerous hybrid versions of it, one of which is the Cora Series of Vinca ( Periwinkle), produced by Goldsmith Seeds, this series has great resistance to the disease which has plagued Vinca growers for decades. It has excellent growing properties in a very sunny area, not so good in heavy shade. In containers on a balcony, in ground beds in parking lots, and garden center edges, this plant keeps cranking out flowers through the hottest weather, and seems indifferent to our heavy Summer rains. Of course, if you live in a dry climate the old garden types can grow well for you, and I envy the people of the semi-arid climates since they can grow many things we cannot. ( They probably envy us our ability to grow the moisture loving plants). 

The old methods of annual-bed preparation still hold true: deep soil cultivation, addition of bone meal and slow-release fertilizer, good drainage, and sufficient water to keep plants healthy. Please notice I did not specify a schedule for watering. I think far too many people believe that plants grow on a fixed schedule, no matter the weather ! This is not only a waste of water, but a prescription for failure. I am not suggesting you watch your plants all day long, but a careful eye toward the weather helps a lot in keeping plants healthy. In the case of Vinca, raised beds of very well-drained medium are required. Enough water to establish the plants before the rainy season followed by irrigation-on-demand watering during the rainy season is all that is needed. The reward is a long term show of flowers, sometimes 6 months or more. Choosing a different type of plant to meet your needs is easier than changing all the conditions to meet the plant's needs, unless you have a prerequisite for having a certain kind of flower in your yard.Some gated communities actually specify what type and color of flower needs to be planted in your yard, and when to plant. These communities need to better understand the diminishing groundwater situations, and the more realistic sensibilities of xeriphytic or low-water landscaping options. Water is a resource we cannot live without, and the water wars of 150 years ago will come again, sooner than we think. Periwinkle is another tool we can use to bring color to our gardens, save us some gardening effort, and save a great deal of water in the process. 

Craig Morell
Pinecrest Gardens 


"wild" Vinca- Periwinkle


March 18, 2011

The Tantalizing Prospects of Hydroponics

I am fascinated by technology, both in my field of horticulture and in most other venues of the modern world. I remember going to Disney World about 25 years ago and seeing "the future of gardening" at Epcot. The future looked pretty bright, with mechanized automated planting of vegetable and grain crops growing in hydroponic media, or in no media at all. The sight of mature lettuce plants sliding around on an elevated rail system with their root systems totally exposed to the air was a sight to remember, tagged with the term "aeroponics". Long before there was a Green movement, hydroponics had the potential to save huge amounts of water, produce huge amounts of  food or foliage, and save huge amounts of fertilizer runoff.

tomato seedling
 Hydroponics has enormous potential for growing plants in controlled environments to produce high yields of product, without the conventional in-the-ground techniques of sunshine and soil. Some of the greatest promises of hydroponics are that the methods can be employed in hostile environments, indoors, underground, or even in space. Israel, Japan ( until recently) and the UAE are leaders in closed-environment hydroponic systems, and produce staggering amounts of food per acre. There is a gentle resurgence in combining hydroponic growing with aquariums, using the water from the aquarium to fertilize the plants, and letting the plant roots filter the aquarium water. There have been substantial experiments done in this hybrid style of system, and the results were impressive. Fish farming and hydroponic horticulture go together perfectly and everyone seems to win. The success would beg the question: why hasn't hydroponics caught on a lot more, and why don't we see huge hybrid aquaculture / hydroponic farms all over the country ?

a simple hydroponic plant watering system

The primary answer is simple, yet depressing: large agricultural hydroponic systems cost big money up front, and venture capital is hard to come by for a "farm". Secondarily, I believe there is  resistance to the idea of growing food plants hydroponically, for many more subtle reasons. It may be because of the complicated-looking equipment needed, or the maintenance of the pumps and tanks. It may possibly be due to the idea that hydroponic fertilizers cost more, are constructed differently than "mainline" brands, and are often harder to find at your local garden store than the types we are all used to using. I have heard people talk about losing the connection to Mother Earth by using the "sterile" methods of hydroponics and that the food tastes different. Let me see if I can de-mystify some of these ideas.

Suncurve experimental hybrid aquaculture-
hydroponic system

Eurofresh Hydroponic Farms- Arizona

Hydroponics is the science of growing plants without soil or in water. Many people have grown an ivy or spider plant in a bottle of water on the kitchen windowsill for years; hydroponics at its simplest.  Loosely stated, plants can be grown in anything that supports their root systems, and allows roots to respire. Many inorganic soil-less media are quite successful  in other venues of horticulture, namely in the orchid business. Fired clay pellets, glass beads, and rockwool are all common media in the orchid world, many of which were borne of the hydroponic world. European growers have used hydroponic methods for decades in growing a great many plants in very small areas under dismal weather conditions. Orchid plants can be grown to magnificent dimensions in the stable and stress-free world of artificial light and on-demand fertilizing.

Table-top hydroponic gardens have been showing up in retail catalogs for the last few years, showing a group of vegetables large enough for a Texas ranch growing in a table-top garden 2 feet long. ( This is misleading advertising). The idea is sound, though, that a unit with a self-contained, recirculating water environment with a predictable light source can grow plants in otherwise difficult situations. Taken to a larger scale, desert states and countries have been using such closed-loop systems for 30 years or more, and all that's necessary for inputs is electricity for the lights and pumps. The numbers are impressive; it is easily possible to produce 3 to 10 times as much per acre with hydroponics than by conventional farm methods. It is easy to produce hydroponic organic vegetables and food products, given the exclusion of pests and diseases from the environment. Without the need for routine pesticides, organic gardening comes easily.

There are, of course, downsides to hydroponics. One must keep the system clean and running smoothly, and take extra care not to contaminate the plants or fertilizers with outside pathogens or pests. One would need to do routine pH and fertilizer tests to make sure the plants adequately tended, and that light bulbs are replaced on schedule. This is routine hygiene for many venues of gardening, just in a different mode. If we can get past the fear of the technology and the up front costs even for small units, I think people will find that hydroponics can make gardening a lot easier and more productive than they'd ever thought possible. After all, how else could you grow a tomato in a condo in Minneapolis in the winter, or have a vertical garden in an apartment in Manhattan ??

Vertical Garden- courtesy of Arch Planners

March 16, 2011

 The Business of "cloning" Plants

One of the hottest topics in horticulture in recent decades has been that of tissue cultured (TC) plants. I have been part of heated arguments for both sides of the equation, wherein both commercial growers and private plant collectors weigh in with heavy arguments. In short, TC provides very large quantities of very consistent, high quality plants to growers at very good prices. With great accuracy, the plants are statistically identical. This is the primary argument both for and against TC plants. Let's look at some of the pro-and-con aspects of tissue culture.

Alocasia lutea
the brilliant color and variegations
due to a stable virus, no longer
propagated by TC  

On the plus side of TC, growers can produce a very predictable crop of plants with nearly identical characteristics on a very predictable schedule. If a grower wants to produce 100,000 Spathiphyllum 'Supreme', a registered and patented plant, he can get the TC plantlets he needs to produce a uniform crop that will grow predictably, with a LOT of background data available to him on how to produce the crop. Many TC plants flower in the same period, and this is especially valuable in flowering plants like Spathiphyllum, Anthurium, and some orchid groups. I left bromeliads out of this group since they can be induced to flower on schedule, with a few months of lead time. Some companies have produced limited quantities of really rare plants such as Amorphophallus titanum, one of the "Holy Grail" species on plant collectors' lists. The plant was hard to find and rather expensive until TC producers made them by the hundreds.

Sometimes the plant that was cultured had extraordinary qualities, and these extraordinary plants can be made available to buyers at very reasonable prices. This has been the case in many rare aroids such as Alocasia reticulata, notorious for dying on no particular cue. A strong variant of it was grown via TC in Homestead at Fennell's Orchid Jungle, and the "new and improved' version is a lot easier to care for. The same easy care goes for hybrids that might have unpredictable qualities if you try to grow them from seed, whereas TC can produce a lot of plants that have all the good qualities you want. The big ideas of TC are consistency of plantlets, and predictability of the resultant crop, with very minor variations. Consequently, the price of the finished plant is a fraction of what  vegetatively produced plant would be. Sometimes, though, growers intentionally grow plants from seed or spores in order to get the natural variations that Mother Nature intended. Tc is not genetic modification as some people think, it is rapid propagation with consistency in mind.

Alocasia reticulata

Alocasia infernalis
photo courtesy of Agri-Starts and
Monrovia Nursery

Phalaenopsis hybrid with unusual coloring
via tissue culture

Paphiopedilum rothschildianum
propagated only by seed or division

Wollemi Pine
until  recently, one of the rarest plants in the world
and widely thought to be extinct, now available at
nurseries worldwide via tissue culture

On the "other" side of TC devotees is the seller of rare plants who makes his living by vegetatively propagating plants in limited quantities to keep the price high, and by ensuring that the number of plants is fairly low. This is classic supply-and-demand economics; keep the interest in a rare plant going by limiting the supply of it. For this type of plant seller, tissue culture is disastrous, akin to the difference between custom built hardwood furniture and mas produced particle board materials at a discount store. For those who have spent hundreds of hours and many thousands of dollars collecting plants, sometimes risking their lives in the process, it is rational to expect a return for your efforts. To nearly fall off some tropical mountain cliff to collect a prized plant, grow it for years while worrying over it through storms and cold weather, sell it at a princely sum to recoup the collecting costs, and then see dozens of it at Kmart two years later is a serious disappointment. This disparity in ideals brings about a quandary. For those who can afford the collector's plants, part of the thrill is the hunt for rarity. For those who enjoy mass-marketed plants, the lower costs bring neat plants into their buying range.

Where can TC go wrong ? The ways it can go wrong are when plants are badly handled in the laboratory, and lots of mutations or inconsistencies show up. While the mutations might yield something really desirable like Alocasia lutea, more often than not the plants come out stunted or warped out of proportion. There have been instances where a plant was 'TC'd' only to lose the parent plants AND the cultures. These plants have been lost forever. There are many tales of horror about labs losing the identity of plants, only to have the plants pop up unexpectedly in another nursery under another name. Patenting a plant can help quell the problem, but problems still arise.Sometimes mutations go badly, sometimes they turn out interesting plants. The positive spin on this is that occasionally a mutant goes in a good direction, e.g. when a plant is more floriferous, shows better flower color due to increased chromosome count, or shows a better plant habit than its "parent".

Perhaps more importantly, where is it best to use TC tactics ? Sometimes a virused plant can be cultured and the virus can be removed from the culture, yielding clean, virus-free plants.  In some cases, rare plants have been saved from extinction with TC tactics such as the Wollemi Pine of Australia. Many top botanical gardens have used TC methods to propagate hyper-rare plants, wherein the plant may not flower often, if at all. Breeding plants the "old fashioned" way by cross pollination is still the method of choice for making new or better varieties of plants. This is the preferred way to see the differences between seedlings, and a breeder will look for variations with good characters.  Unfortunately this is a slow way to make millions of uniform plants. Fueling a large demand for uniform plants requires the rapid propagation techniques of tissue culture. There are places in the modern plant world for both of these tactics, and each has a permanent home in our world. Especially in agriculture, TC changes the way we eat, feed the hungry, and bring about positive change in under-developed countries.

Craig Morell
Pinecrest Gardens     

March 14, 2011

Flowering Bulbs for the Subtropics

Cornukaempferia aurantiaca
"Kaempferia Jungle Gold"

Curcuma roscoeana
"Jewel of Burma"
 Earlier in my life, I lived in temperate Milwaukee. I remember planting bulbs in the Fall, and if you staged  and designed them right, you could have a long running show of flowers starting as early as March, with Crocus flowers and Siberian Iris coming up through the snow. What a switch from Milwaukee to Miami ! There is a far smaller list of bulbs to work with in Miami than in temperate climates, but there are some choices available. Many of the stalwart choices, like tulips, crocus, jonquils, and gladiolus, are hard to grow in the extreme south. In California, there are lots more options due to to the more Mediterranean climate and cooler winters of the coastal areas. In South Florida, we have to cheat a little. There are some bulbs that can offer diversity to a garden collection, but they need some extra care to bring on floweringListed below  are some of my own choices, with myriad others to choose from.

Hippeastrum papilio
Butterfly Amaryllis

Caladium 'Gingerland'


Hippeastrum 'Merry Christmas'

There are swarms of hybrids in each of the genera seen above, with more on the way. Even with the old-fashioned Caladium types, there are new varieties arriving from Thailand, as well as from breeding programs in Florida. The winter-deciduous Kaempferia and Curcuma species are excellent container plants, and can make a great flower show in Spring when the plants are left to grow to specimens.Some of the larger Curcuma species like C. elata make handsome landscape plants, but remember to turn off the water when the plants go dormant.

In most cases, these bulb plants need a dry winter rest of at least 6 weeks, preferably in a rain-free area, out of the ground ( insects love to munch on the bulbs), and in bright filtered light. When the new growths appear, put the plant into as much sunlight as it can handle, and resume normal watering and feeding. Especially with the tropical tubers and bulbs, the plants enjoy frequent fertilizing and almost daily watering to keep up with their rapid growth. A rich organic soil that has good drainage is a prerequisite for good growth. Slow release fertilizers such as Osmocote and Nutricote are excellent sources of ongoing nutrition. The old fashioned methods of adding bone meal and superphosphate to the soil at planting time still work well in making great, stocky tubers or bulbs. The tactics for success are strong light, plenty of food and water during active growth, a watchful eye for snails, and attention to their winter dormant periods. One notable oddity is the Jewel of Burma, which wants to go dormant in mid-Summer ! Give this plant its due attention, and the tangerine-orange inflorescences are well worth the effort. Many growers have set aside their efforts to grow deciduous plants, yet I feel that the plants deserve a Renaissance. After all, the plants save you several months of care !

Craig Morell
Pinecrest Gardens     

March 8, 2011

Those Marvelous, Mystifying Medinillas

Medinillas are in the same family as Tibouchina, Melastoma ( for which the family is named), and a number of other popular plant genera, most of which have attractive flowers. In the case of Medinilla, many of the cultivated species and selections are of special interest, since they are attractive plants, often bearing spectacular flowers heads. These plants are frequently tree dwellers, and are easily cultivated as basket plants. In the larger species such as M. magnifica, M. myrianthina, and M. miniata , the plants can form small trees ! Here in Miami, these species can be grown  with some success as either very large containerized plants, or in 20-30" diameter wire baskets filled with a moisture-retentive epiphytic mix suitable for Phalaenopsis. There are well over 100 species in the genus, some of which are very petite species that climb around on rocks, some of which reputedly attain tree status, with some eye-popping inflorescences. Most of them are appreciative of moderate temperatures, even if they come from wet tropical areas. A great many species come from moderate altitudes in tropical mountainous areas. In Europe, several species are cultivated as houseplants, which may indicate that the plants don't need hot, humid conditions, but rather, moderate, stable conditions with filtered light. Even in downtown metro areas in temperate cities, I see champion quality begonias and gesneriads growing in store windows with a little extra attention to watering; I believe many Medinillas willl grow in the same conditions.

M. magnifica

M. magnifica

M. magnifica

M. miniata

M. speciosa
courtesy Tropical Designs

M. alata, aka M. 'Lalique'

The stunning inflorescences on many species are actually aggregates of small flowers, often followed by numerous black berries containing minute seeds. The seeds often germinate well, but extra care needs to be taken to make sure they have stable conditions in which to germinate. Follow the same methods used for growing begonia seed or fern spores, and you should be quite successful. The plants do certainly appreciate calcium-free water when possible, and I've seen some fabulous plants grown in collections where rain water or distilled water was used as irrigation. Although the predominant color in the genus is pink-lavender, there are very pale pinks, a reputed pure white, and the relatively new-to-cultivation orange-red of M. miniata. In most species I know of in this area, the plants are fairly easy to cultivate, keeping in mind they are tropical ( they fizzle below 50 F), they like pure water, and they need ample growing room in a basket or pot of orchid mix.. The plants are becoming much more available due to tissue culture, and even grown as an annual in many states. The genus is worth a try in a plant collection, and is yet another option for color and style in the plant collector's array of  specimens.

Craig Morell
Pinecrest Gardens      

March 3, 2011

Tools of the Garden Trade-part 4- Shovels

Ah, the lowly shovel. So many people have them in their tool sheds, and probably have just one for all uses.As with so many tools, there is the perfect tool for almost any job, and rarely does one shovel do everything. There are shovels with very long handles and very narrow blades for drainage ditches, and short, stout spades for working in close quarters. Knowing a little about each type can greatly assist in digging  holes or removing plants or cultivating soil. 

Wide array of shovels

cap rock shovels aka root spades

There are numerous features of any shovel to consider when buying one. The handle material will greatly affect the cost and utility of a shovel. Some of the solid core or metal handled shovels can cost $ 60 or more, whereas the hickory handled tools of the local garden center may be $ 20. Extra long handled shovels and spades are used for digging very deep holes, or for root-pruning a tree. These spades are made of a steel that can be sharpened easily and often. Cultivating shovels or forks are made of a harder steel that resist wear when digging through rocky soil. The common point-tip spade is useful for digging holes in softer soil, but works even better when a sharp edge is filed or ground into the cutting edge. Square point shovels are often used as scoops, lifting sod, or edging beds, in addition to digging in very soft soil. Also consider your own size and strength; a 6 foot professional gardener will need a different shovel for a task than a 5 foot occasional gardener would. One item to note: shovels are not pry bars, although they frequently are used as one. The idea is that a sharp shovel blade with a long handle is used to cut roots or dig something up, not to lever it out of the ground under heavy stress. Pry bars are a far heavier steel and are perfect for levering a plant out of the ground once the roots are cut.

For digging in the very rocky coral soil in Miami, we prefer a rock spade with a very heavy solid handle. Locally these are called Pony shovels, cap rock shovels, or root spades depending on the area of town. These shovels can weigh 20 pounds, and are effective in cutting into and through the coral rocks in this area. Some shovels have very short handles, useful for digging underneath bushes and small trees while you work on the ground. One of the most frequent mistakes is that people will stand in one place and stab the ground with a shovel, trying to penetrate the ground. This is a lot of trouble, and causes a lot of stress on your wrists and shoulders. It is far more effective to place the shovel where you want to dig, and step solidly on the shoulder of the blade. Lift the soil out of the hole, and repeat, step by step until you finish the task. It is equally important to bend your knees when lifting soil or plants, and take the lifting strain off your lower back.

Many old-time growers will retire their shovels in the inactive season by wiping the shovel blade and any metal parts with heavy oil, then hanging up the tool for the season. This is an excellent tactic, useful in any climate for almost any digging tool. As with most tools, the right tool for the task + some careful instructions = success and less stress. 

Craig Morell
Pinecrest Gardens