Clay

It's been said that soil is the foundation of civilization. If society does not take care of its soil, it will eventually fail. This may or may not be an exaggeration, but it is definitely no exaggeration that soil is the foundation of any garden.

Clay, or better put, too much clay, can, at worst, be the downfall of your garden, or at best, make gardening much more difficult and challenging.

I have had some experience with clay. I gardened for 29 years in Clemson, South Carolina, an area made famous by a book written in 1942 by Ben Robertson. The title of Robertson’s book is Red Hills and Cotton. By the phrase, red hills, Robertson was referring to, red clay. When the first European settlers began farming the northwestern corner of South Carolina in the latter half of 18th century, it was covered by a foot or more of rich, dark brown humus, which had been building up on the forest floor for thousands of years. For farming, it was like having money in the bank. But good soil, like a bank account, is something you must take care of, or you will eventually go broke.

Underneath the topsoil was hard, red clay. Unfortunately, due to the combination of hilly terrain and poor tilling practices, the topsoil slowly eroded away. By the 20th century the topsoil was gone, but the farmers continued to try to eke out an existence, in a place that now resembled more of a moonscape than a landscape. The arrival of the Great Depression in 1929, and the collapse of the demand for their crops (mostly cotton), was the last straw. Many farmers were wiped out, losing their farms to the banks, or selling them off for as little as a dollar an acre. These farmers were cursed by their forefathers, who, instead of improving the soil for a better tomorrow, farmed for short-term productivity, allowing the soil to slowly erode away.

Surprisingly, clay soils in general tend to be fairly high in plant nutrients. The problem is the structure and texture of the soil. Clay particles are extremely fine and flat. They fit tightly together, making it difficult, if not impossible, for plant roots to penetrate, and even if the roots do manage to grow, it allows little or no air to reach them. Plants breathe through their roots, and if they cannot do this, they die. When it rains, water fills what little air pockets there are in the clay, and the roots cannot breathe. During a dry spell, clayey soils maintain moisture longer than sandy soils, but when they do eventually dry out, they become as hard as rocks.

Sandy soils, on the other hand, are made up of larger particles, with a loose structure, and are easily penetrated by plant roots. In counterbalance, sandy soils tend to be lower in plant nutrients than clayey soils; they also dry out faster. What you want in your soil is a nice balance between clay and sand, and most importantly, you want lots of organic matter.

Quoting from Home Vegetable Gardening, a publication of the Clemson University Extension Service, “Oftentimes gardeners get caught up in the beauty and bounty of the vegetables without remembering that the foundation for any healthy garden is soil. A good soil allows air, water and nutrients to be absorbed by plants’ root and lets those roots roam freely. How do you build healthy soil? Add organic matter.” Organic matter improves drainage in heavy clay soils. It holds the clay particles apart, improving air and water movement in the soil.

My garden in Clemson was located in an area that had once been a flood plain next to a creek. When our house was built in the 1960s, the builder covered the rich soil of the flood plain with a heavy clay loam. When I began gardening I added huge quantities of organic matter to it in the form of tree leaves, horse manure, and wood ashes. Within a couple of years I had a soft, rich loam. Plants thrived in it. I continued adding organic matter, and the garden just kept getting better and better.

When we purchased our lot in Costa Rica in 2006 it was covered with a silty, dark (almost black) volcanic soil. Unfortunately, this rich topsoil was only a foot or so thick. Underneath was hard red clay. During the excavation process for our house a lot of subsoil was dug up, and, unfortunately, bulldozed over the top of the topsoil. A couple of inches wouldn’t have been too bad, but the average depth of the clay is eight inches. If I were to start a brick factory, I would have been in business. As far as gardening, it was a catastrophe.

It was in April of 2009 that I got my first inkling of how bad the situation was. It was near the end of the dry season and I was going to dig up an area in preparation for planting some grass. I tried to drive a shovel into the soil. It was solid clay, and the shovel just bounced off. It didn’t matter how hard I banged on it with the shovel. It wouldn’t budge. The next day it rained. I tried with the shovel again, and this time the shovel went in, but it was almost impossible to get it back out -- it was a sticky mess. It was so sticky, in fact, I could not shake the clay off of the shovel, and had to use a knife to scrape it off. Breaking up sod is a hard enough job as it is, but breaking up heavy clay is next to impossible.

Clay on left; loam on right

So, how does one tell if they have a heavy clay soil? Many clays are red; so a red color can be a good indication. But there are also yellow, gray, and even white clays. Take a fistful of soil in your hand and squeeze it as hard as you can. When you open your fist, if the soil maintains its shape exactly, you have a clay soil. If you then take it between your fingers and roll it, like you would with modeling clay, and it comes out ropey, you have a heavy clay soil.

Both clay (on left) and loam (on right) have been squeezed. The clay maintained its shape.

WHAT TO DO?
Okay. So, we know clay is a blessing for brick-makers, and catastrophe for gardeners. The question now is: What to do?

Plan A was to attack it piecemeal, and see what would happen. I bought two dump-truck-loads of topsoil, a couple of cubic meters of sand, and several bags of lime, and I began composting organic matter like mad. For my shrubs and trees, I dug large holes and filled them with my new homemade potting soil mix. It was the dry season, so I watered everything about twice a week. Things looked pretty good. When the rains began in mid-April (almost a month ahead of schedule) the plants really began to look quite good. Then on July 20th we got a four-inch rainfall in about three hours. Heavy rains continued several times a week after that. Soon I began to notice the plants were stressed. Leaves turned yellow and began to fall off and some of them began to wilt. What I had done was to make rainwater collection basins. The rain hit the clay soil, which it could not penetrate, so it ran downhill until it found the holes of good soil, where it collected, and rotted the roots of my plants.

About two weeks later I called my gardener in a panic and he and his helper came over and the three of us dug drainage ditches around everything. The plants began to recover, but then in August and September we averaged not quite an inch of rain a day. We shall see if anything prospers, or even survives.

Plan B is to scrape off the top of the soil with a backhoe, exposing the rich, organic soil underneath. But we will have to wait until the dry season for this, due to the difficult texture of the soil and the potential erosion and flooding that could result. And what will we do with all of that clay?

Today's blog has been a rant about clay. I apologize, but I had to get it off my chest, at least, for a while.

Happy gardening!

Angel's Hair Mimosa

Here is another very neat plant for your garden -- Calliandra calothyrsus, commmonly known as angel's hair mimosa (pelo (or, cabello) de angel). It captured my imagination the very first time I saw it. I don't remember where it was, but I was in a garden at an ecoloodge somewhere in Costa Rica. It was early morning and I was out looking for birds. A shaft of sunlight shown down through the shadows onto some dewy blossoms. The bright red staminal filaments glistened spectacularly, like one of those fiber optics lamps. At breakfast I told the rest of our group about the dazzling flowers I had seen. "come on, come on," I said. "You simply have to come and see this amazing tree . . . the flowers are absolutely psychedelic." But by then the garden was flooded with light and the blossoms, though still very pretty, could not compare with what I had seen an hour earlier. It was impossible to capture the moment.

Fiber optic light (see any resemblance?)

One morning, not long after moving to our new home in Concepción de San Rafael de heredia, my wife, Maria, and I were out walking on Ciénega Road, which follows an intermittent mountain stream. We noticed several angel's hair mimosa growing wild near the stream, and it just happened to be the right time of year for them to bloom (late in the rainy season). Maria pulled up several young saplings and brought them home. The tree seemed to like moist soil and partial shade. We looked around our property and found the right spot. She planted several of them, and one survived (I accidentally cut down some of them, not recognizing them among the weeds). A year later it is over ten feet tall and has set out a large array of blooms. When the buds first appeared the grayish saltators (a type of bird) began eating them (the locals call them "point eaters (come puntas). But the birds eventually moved on to other types of buds to eat.

Angel's hair mimosa is native to Central America and Mexico. I bears beautiful feathery leaves on thornless branches. The leaves fold up in the evening. It grows rapidly and can reach 12 meters in height. It can get a little straggly and weedy looking -- we might try pruning it in the future to give it some kind of shape. It can tolerate a wide range of soils, but does not tolerate poor drainage, and grows in either light shade or full sun. It can be grown from sea level to over 5,000 feet, but seems to do best at the higher elevations.

The Calliandra mimosa genus has about 200 species and it is in the fabaceae (legume) family. These trees take nitrogen from the air and with the help of bacteria growing in their roots, fix nitrogen into the soil -- a good tree to have around. It is occasionally grown as a shade tree in coffee plantations and in hedgerows.

Angel's hair can be started either from seeds or seedlings. The seeds should be soaked in cold water for 48 hours (some say soaking it in very hot water for several hours works too). Many Costa Rican gift shops carry small packets of the seeds, distributed by El Arca Verde de la Plantas, S.A. I went ot the web site printed on the package, but was unable to pull up any information about the company.

Happy gardening!

Fuchsia Triphylla

When we first moved here we noticed that our neighbor, Victor,  had a type of fuchsia growing in his yard that always seemed to have hummingbirds hovering around it. We looked for it in local nurseries, without any luck. So, my wife Maria pulled some rhizomes off one of Victor's plants, with his permission, of course. It has been doing very well, and is visited regularly by hummers. The more I get to know this plant, the more I like it. It is very healthy and has bloomed continuously for a solid year now. It seems to have no pests and requires almost no upkeep, other than weeding around it every couple of months, and maybe watering it every two weeks or so in the dry season. Besides the beautiful crimson flowers, the velvety foliage is attractive, and the plant has required no pruning or staking.

Fuchsia triphylla

But what got me absolutely raving about this seemingly perfect plant was an incident that happened this morning. The fuchsia is located near our backdoor, and happens to be the first plant our golden retriever encounters when he goes outside. As a result, it gets peed on several times a day. Maria and I agreed that I had better put a fence around the fuchsia before it got burned by the nitrogen from the dog urine. I decided to do a good weeding before I put up the fence. The soil, I discovered, was almost solid clay, and the plant was growing on top of a 40-pound chunk of cement. Wow -- what a plant!!! I removed the cement and some of the clay and gave it some nice potting soil.

I didn't know what kind of fuchsia it was, so spent quite a bit of time searching the fuchsia images in Google. At first I thought it might be a Fuchsia boliviana, but eventually found some photographs that matched what we had -- Fuchsia triphylla. It is native to the islands of the Caribbean and is now grown throughout the neotropics. It likes full sun, but also does well in partial shade, and it likes high temperatures of around 80 and lows around 60, which matches the average temperatures we have here to within a few degrees. It only grows about 2-3 feet tall, whereas the Bolivian version can grow to 5-6 feet. We have a seedling of a Fuchsia boliviana that we got from the Trogon Lodge in San Gerardo de Dota, again, with permission (see photo below).

Fuchsia boliviana seedling

 The flowers of the boliviana are at least twice as long as the triphylla. One important difference, we noticed the hummers were piercing the sides of the boliviana flowers, near the base, meaning they were probably NOT pollinating the flowers, whereas the hummers visiting the triphylla flowers were sticking their beaks up through the center of the corolla, meaning they were probably pollinating the flowers.

Fuchsia triphylla flowers

Oops! I just noticed in the close-up photo above of our triphylla blossoms that there is a telltale scar at the base of one of the flowers . . . maybe a hummer hole. I'll have to pay closer attention.

Happy gardening!

One Year - an Assessment

We've been gardening in Costa Rica for a year now. There have been many successes and failures. It is time to tally the results.

Background
When we bought the property in 2006 it was covered with a dark volcanic soil. The northeast quadrant was especially good. The owner was growing corn and squash at the time. In 2007/08 it lay fallow, and became overrun with African star grass, an invasive, exotic species. During construction in 2008/09 the builder ended up with a huge pile of red clay, which he (in our absence and without our knowledge) bulldozed over the top of the volcanic soil, to an average depth of about eight inches. When we arrived in 2009 about three quarters of the lot had been basically destroyed by the red clay. The northeast quadrant was still rich, black volcanic soil, but in several places had been compacted by heavy equipment and mixed with building debris -- sand, gravel, chunks of cement, broken glass and ceramic tile, rusty nails and wire, pieces of wood, plastic, Styrofoam, etc. The red clay was also filled with debris.

We began digging up the northeast quadrant and removing the debris. After two months we had restored, and actually improved the soil -- sand had been added to the silky smooth volcanic soil, giving it excellent drainage. We are gardening this area intensively.

In the red clay area we had two dump-truck-loads of black soil delivered. We mixed this with sand, lime, rice hulls, and compost, and began digging large holes for planting trees and shrubs. Things went well until July 20, when we received 3.7 inches of rain in about three hours. Most things in the red clay area went downhill from there. What happened was this, the rain could not penetrate the red clay, so the water ran downhill until it found the shrub/tree plantings (with the good soil), where, having no place else to go, it soaked in and sat there, damaging the roots. We have added drainage ditches since then, and most of the plants are hanging on, and some seem to be actually recovering.

Other major problems encountered were: grubs, stalk borers, gophers, leaf-cutter ants, and high winds (in December and January).

We are also working on a vegetable garden featuring a windbreak and raised beds with wooden siding.

There have been many failures and some complete catastrophes. Most of the failures are in the red clay area. Most of the successes are in the black soil area. Originally I called our gardening a "work in progress." Since July 20 I refer to everything as "an experiment." We have learned many lessons, which we are now applying to create our future garden in paradise.

THE BIGGEST SUCCESSES (Top 20, ranked)

1. Impatiens -- planted five New Guinean impatiens near the front door in black soil, each a different color, They are the first thing guests comment on. The white one is two and a half feet tall!
2. Angel's hair mimosa -- (Calliandra calothyrsus) -- my wife, Maria, dug up some very small saplings along the side of the road. One survived and is now eight feet tall and covered with flowers (planted in rich, black soil, in a shady area).
3. Sunflowers -- now on our third planting of medium-sized, multicolored sunflowers. They can grow in almost any soil; just give them lots of sun; hummingbirds and honeybees love them.
4. Targuá (Croton draco) -- a native, fast-growing pioneer species; planted a foot-tall sapling, dug up from the side of the road; now seven feet tall and blooming.
5. Wandering Jew (Tradescantia zebrina; Cucaracha) -- two varieties acquired from coffee plantation next door. Doing very well in shady area; they make a nice, lush ground cover.
6. Poró (Erythrina lanceolata, coral tree) -- full-size tree that came with the property, growing on north property line; sheds its leaves and blooms from November till march; Baltimore orioles love it.
7. Jacaranda (Jacaranda mimosifolia, Nazareno) -- brought to us by our gardener; doing very well in less than average soil.
8. Avocado tree near driveway -- native (criollo) species that came with the property; all of the cement mixing took place around it, and it made it through like a trooper; loaded with fruit, May - July.
9. Purple taro (black magic) -- planted in good soil; prolific.
10. Grapefruit -- pink variety; planted on steep slope, in average soil; doing very well.
11. Tree tomato (Solanum Betaceum, tomate de palo) -- my wife dug it up in a nearby coffee plantation; huge leaves; already bearing fruit (fruit, leaves, and branches resemble an egg plant more than they do a tomato).
12. Fuchsia (Fuchsia triphylla) -- my wife pulled up a seedling along the side of the road; hummingbirds love it.
13. Caladiums -- green with cream-colored freckles; given to me by a sister-in-law; planted in rich black soil in partial shade; prolific.
14. Güitite (Acnitus arborescens, wild tree tobacco) -- native species; produces fruit for the birds; planted in 2008; doing very well; many volunteers popping up around the property.
15. Coleus -- many varieties planted from cuttings in shady areas; tolerates many types of soils.
16. Porterweed (Stachytarpheta frantzii, rabo de gato) -- purple ones doing very well (pink ones doing okay); hummingbirds love them.
17. Agapanthus -- planted in the dry season (when they normally bloom); they began blooming almost immediately.
18. Banana -- several on the property planted in clay are doing poorly; one planted in black soil doing very well.
19. Jalapeño peppers -- bought a small flat at EPA (Costa Rica's equivalent to Lowe's), not knowing what variety of pepper they were; prolific.
20. Brazilian red cloak (pavoncillo rojo) - planted four-inch high seedling; now five feet tall and growing vigorously.

Passiflora (before the gopher got it)

THE WORST FAILURES (Bottom 10, ranked)

1.  Passion flower (passiflora vitifolia) -- did terrific until gopher ate the entire root system; planted a second one with an underground wire cage to protect it from the gophers.
2. Chayote -- planted in unprotected area with less than ideal soil; 70+ mph winds in January tore it up.
3. Impatiens -- my wife pulled up several plants from a nearby coffee plantation (where they were growing wild); by accident they were planted in organic fertilizer from a nearby coffee processing plant; we think the fertilizer was very acid; they died.
4. Vinca -- same thing happened to them as the impatiens.
5. Celery -- planted them twice in different locations, and their leaves seem to just burn up.
6. Eucharist lily (Eucharis grandiflora) -- tried planting them in various habitars, with no luck.
7. Corn -- wiped out by grubs.
8. Bamboo -- planted a bamboo fence in the dry season; not weeded or watered because we thought the bamboo could fend for itself; we were wrong.
9. Mango -- we purchased a variety that does well at high elevations; it did well for a while, but was attacked by fungus; now spraying with copper sulfate.
10. Bougainvillea (veranera) -- did okay in the dry season, but when the heavy rains came they began to look poorly and shed their leaves.

Happy gardening!

The Bird Feeder, Part 1

One of the neatest things we did during our first year in Costa Rica was to put up a bird feeder. It is a chore to stock it each day, bit it provides us with endless hours of entertainment. In South Carolina we had three types of feeders: seed, suet, and nectar. On our trips to Costa Rica, however, we never saw a seed feeder, but saw lots of fruit feeders. We tried putting up a fruit feeder back home, but succeeded only in attracting butterflies and wasps. As for seed feeders at our new location in Costa Rica, we knew it would probably attract rufous-collared sparrows, and maybe some pigeons and doves; we have put this project on hold.

Family of mot mots having dinner

Soon after our arrival we explained to our handyman, Don Oscar, that we wanted a platform-type fruit feeder that would allow the small bits of fruit to fall through the bottom, and would not collect rainwater. After a little thought, he designed a feeder with a square, wooden frame, with one wooden slate across the middle for support. The top is covered with one-inch size metal screen. It measures about 15 inches on a side, and is mounted on a 2-inch square iron pipe, which sits on a cement base. The platform sits about five feet off the ground. Later we added some metal pegs on which to stick the fruit, so that the birds would not accidentally knock it off the platform.

In South Carolina we had had problems with squirrels, and built or purchased various devices to keep them away. We have squirrels here too, but so far they have been almost no problem. We did see an opossum on the feeder one evening, something we never saw back home.

We stock the feeder regularly with plantains (the birds don't like them too ripe) and sometimes with papayas. We have tried bananas, oranges, lemons, mangoes, and pineapples, but the birds seem to prefer a diet of plantains and papayas. Our neighbor puts up watermelon, and says the birds love it.

We have been surprised by the different types of birds that come to the feeder. Would you believe, woodpeckers eat fruit? The birds that come on a regular basis include; clay-colored robins, grayish saltators, black-headed saltators, great kiskadees, blue-gray tanagers, Hoffmann's woodpeckers, and blue-crowned mot mots. Occasionally we have flame-colored tanagers, Baltimore orioles, and melodious blackbirds.

Opossum raiding the feeder

If we let them, the birds could eat us out of house and home. After much debate, we decided to limit our hospitality to two plantains and a quarter papaya per day. The robins are the most regular, and voracious, eaters, followed by the mot mots. Frequently after sunset, if we peer out our window, in the dim light we can make out a mot mot getting his last bedtime snack.

Happy gardening!

Edible Landscaping -- Xanthosoma Sagittifolium and its Cousins

I love this plant. It makes a statement in the garden, and , it is so . . . well . . . tropical. It is easy to propagate, easy to grow, is native to the American tropics, and has both decorative and nutritive qualities. Wow! What more could one ask for?

Xanthosoma Sagittifolium

In Costa Rica it is called tiquisque. In many other countries it is called malanga. Its close cousin Colocasia esculenta, originally from Asia, is called ñampí in Costa Rica, yautia in some other countries, and taro in hawaii. To make things interesting, in some countries the names are reversed.

Colocasia Esculenta

 Xanthosoma, Colocasia, and related plants are in the araceae family, sometimes referred to as the arum family, or singularly as an aroid. Almost by definition, they are tropical. Only a few species are native to temperate North America. They tend to grow in either shady or swampy locales. These include Jack-in-the pulpit and eastern and western skunk cabbage. At our old home in Clemson, South Carolina, in addition to Jack-in-the-pulpits, we grew some tropical araceae. We had to mulch them heavily in the winter. These included both Xanthosoma undipes (elephant ear) and Colocasia esculenta (sometimes called "black magic"). We have seen both of these in Costa Rica (we have some black magic near our front door). There is also a larger form of elephant ear from Malaysia (Alocasia macrorrhizos).

Black magic

 Characteristic of the genera Xanthosoma and Colocasia are large, more or less arrow-shaped leaves and thick, succulent stems. The flowers feature a pale yellowish-white spathe enclosing a spadix. They typically grow about four feet tall, but can get taller. Xanthosoma can be distinguished from Colocasia by the way the leaf is attached to the leaf stem. In the Xanthosoma the stem is attached at the edge of the leaf, on the backside of the arrow shape. In the Colocasia the leaf stem is attached within the area of the leaf blade (peltate).

Xanthosoma spathe and spadix

 These are all light-loving plants, but they will take a little shade. They need rich, moist soil. You can frequently see them growing wild on the sides of streams. They can be grown from sea level to over 5,000 feet elevation. To propagate them , break off offshoots of the corms, or pieces of corms with shoots, and plant them a couple of inches deep in the soil. They multiply rapidly and should be divided at least once a year.

Tiquisque tubers

 The starchy tubers of both Xanthosoma sagittifolium (tiquisque) and Colocasia esculenta (ñampí) can be found in any market or vegetable stand in Costa Rica. They are eaten in soup and sometimes served slice and fried. They are purported to be good sources of vitamin A. Do not attempt to eat the tubers raw because they contain calcium oxalate crystals and other toxins, which irritate the mouth and throat.

Happy Gardening!

August Weather -- Rain, Rain, Rain

This is the first year we have measured the rainfall here, so we can make no comparisons with previous years. However, the locals say they can't remember a rainier August than this one. We had measurable rainfall for 28 of the 31 days. I kept telling myself I liked the sound of the constant pitter-patter on the roof, but when we had a rainless day on August 30 I realized what a relief it was. In the afternoon, when it normally would have been raining, we sat on our balcony to enjoy the view, put on Enya's A Day Without Rain, and reveled in the dry, balmy weather.

Total rainfall for the month was [roll of drums] . . . 27.2 inches. The month came in like a lamb with .1 inch on August 1, followed by two rainless days, and left like a lamb, with no rain on August 30 and only .1 inch on August 31. In between, it was all lion. Ten days had more than an inch, the heaviest coming on August 6, with three inches. Most of the time it was overcast.

The high temperature was 80 degrees, on August 23; the two lows, 57 degrees, on August 18 and 19. Winds were light to moderate, generally from the west.

It was a tough month on those plants located in the clay soil. The ones in the "tierra negra" did fairly well.

September and October are normally the rainiest months of the year. We shall see. 

Happy gardening!