...and move it all around

Tempus fugit! It's already been more than a year since our first post (Hello there world - August 9, 2011). Wow! Never thought we would still be doing this after a year. But here we are, non the wiser. Well, maybe just a bit wiser.

When we started everything was going great, full steam ahead. We were producing lots of tomatoes, peppers, cucumbers, flowers, strawberries, etc. Happy times! All that stopped a few months ago. Plants languished, production went significantly down, growth stalled. Part of it was poor care and maintenance (mea culpa) but that couldn't be the whole problem. Something else must be at work. After some deep thinking (and online research) I think we might have stumbled upon the root of the problem: Soil.

Soil!? But isn't soil one of the advantages of container gardening. Not having to worry about it. So we thought. In sub-tropical climates container gardeners rarely have to worry about soil. They plant at the beginning of the season with fresh soil and at the end of the season when plants die soil is discarded (or even better, used towards the compost bin). Fresh soil is then used when spring comes around. In tropical climates where perennial plants are common soil becomes an issue.

Here's what happens to soil after time passes.

1. Nutrients are depleted - Nutrients are depleted from the soil as plants consume them. Not a real issue with containers since we administer fertilizer on a regular basis (you are administering fertilizer, right?).
2. Soil collapses - Soil tends to collapse and become compacted. Nutrient absorption may be reduced due to this. However, this is usually not a big concern in containers.
3. Pests and diseases - Pests and diseases develop in soil as time goes by. These organisms may become dormant until the right conditions (temperature, host, etc) are present. Diseases typically affect a family of plants rather than a single species. Very important since a few common plants (tomatoes, peppers, potatoes) belong to the same family (Solanaceae).

Pests and diseases are the biggest concern to reusing soil. Soil harbors many types of viruses and bacteria. Healthy, mature plants are barely affected by these organisms. However, young plants are vulnerable (plants behave similar to humans, the young and the old are usually the most prone to disease). Therein lied our problem. We had a few combopots with spices, greens, ornamentals, and fruits. Spices are, with some exceptions, perennials; greens are annuals; ornamentals may be either annuals or perennials. Fruits usually have to be replaced after a season, two at the most, since their production is greatly reduced as time goes on. Since we didn't want to lose our spices and herbs we kept out pots intact, soil and all. Mistake 1. Then we went and compounded our mistake with Mistake 2: Replanting species in the same containers. Right on cue diseases started attacking our young plants with most plants never being able to produce fruits.

If you have monopots the solution is simple: Discard soil at the end of the growing season. But what to do with combopots where soil cannot be completely discarded? There is a simple solution. Crop Rotation. This technique is used by large scale farmers around the world. The idea is to move crops around and not grow plants from the same family in consecutive seasons. So if you planted tomatoes in one container your next crop could be arugula or lettuce. If you had peppers then you can alternate them with strawberries or onions.
Simple, right? So learn from our mistakes and rotate your crops.

Sometimes neutral jing is your best option

Today's title is a homage to one of our favorite cartoons: Avatar - The Last Airbender (highly recommended for both adults and kids). In this cartoon there are jings which represent options for directing your energy. There is positive, negative and neutral jing. Positive = advancing, progressing, attacking; Negative = retreating, evading; Neutral = not doing anything.  A lot of times when gardening the best option is to do nothing. Just sit back and let nature take its course.

Remember those whiteflies we were battling (see Pests: Whiteflies)? Well, they're gone. How did we eradicate them you ask? To be honest we don't know. Here's what we tried. We bought some sticky traps and set them around our plants (negative jing). The traps caught every insect imaginable but very few whiteflies. We also tried to kill with our bare hands (oh, the humanity!) as many of the flies as we could find early in the morning when the flies are not very active (positive jing). None of these things were very effective. In the end we just let them be and nature took its course (neutral jing). We believe the whiteflies were eradicated by a combination of factors.

Biological: Spiders set-up shop where the whitefly population density was highest. They probably helped control the adult population.
Environmental: Temperatures dipped which normally results in less whiteflies. If true it means they might come back in spring or summer.
Luck: A highly likely candidate. Never underestimate the power of pure dumb luck.

So there you have it, our experience on how to control whiteflies. Do nothing and just enjoy your garden. Join us next time when we might actually do something.

Pests: Whiteflies

Adult whiteflies (photo from Wikipedia)

Today's lesson: Cause and effect. A few weeks ago we noticed some very small, white flies on one of our verbena plants. When the leaves are moved around all the little flies started flying everywhere. It looked as if you had shaken one of those toy snowglobes. It was just a curiosity and we paid no additional attention to it. In retrospect this was a mistake.

We have two verbena plants. One is in a pot with a tomato and oregano while the other is in a pot by itself. We noticed something was amiss when the plant in the mixed pot was flowering while the one by itself started to languish. We also noticed that the bottom of some leaves were covered in black spots. Curiosity turned into dread. These little flies were no good.

These flies, called whiteflies, are a common pest in most types of gardens. Sadly for container gardeners in Puerto Rico these flies thrive in hot weather. There are two common types of whiteflies: the greenhouse whitefly (Trialeurodes vaporariorum) and the silverleaf whitefly (Bernisia sp.). Whiteflies lay small, oblong eggs on the underside of leaves. They go through four nymphal stages with the final stage being the flying adult. Through all stages they feed on plant juices which weakens the plant. They excrete a substance called honeydew which as its name suggests is sweet and sticky. Ants love this stuff. If you see many ants in your plant you may have an infestation of whiteflies or aphids (Editors note:Always follow the ants. They'll lead you straight to the problem.).  Besides weakening your plants whiteflies are capable of transmitting viruses such as tomato yellow leaf curl. They also cause leaves to develop a black sooty fungus.

Controlling whitefly populations is difficult. They are usually resistant to most insecticides. The best approach is prevention. Carefully observe your plants every day for signs of weakness, yellowing or emergence of eggs. Removing affected leaves or plants will ensure control of whitefly populations. If you are past prevention (as we are) there are several things you may try.

• Vacuuming adults early in the morning when it is still cold. Use a small hand vacuum to avoid damaging your plants. Place vacuumed flies in the freezer to kill them off.
• Application of an organic insecticide soap will kill some flies.
• Yellow sticky traps will attract flies. These traps can be used to monitor and control populations.
• Natural predators. Ladybug larvae, Green Lacewing, predatory mites and some birds are known to kill whiteflies.

So which methods will we try? We don't know yet but stay tuned to find out.

Pests: Leaf Miners

Leaf miner damage on our tomato

Sometime ago we noticed some strange markings on some of our tomato and cucumber leaves.  They were silvery and looked like trails made by a drunk animal. We looked around for signs of additional damage but we didn't find any. Since the plants did not seem to be suffering any ill effects from it we let them be. However, our curiosity remained. In search for answers we went to the bible, The Bountiful Container by McGee & Stuckey's (highly recommended). It mentioned that silver trails are usually a sign of slugs. We searched and searched but we never found a single slug.

Yesterday, I went to one of my favorite garden blogs (and quite possibly the inspiration for this blog), Life on the Balcony,  and right there on the main page was the answer to our question: Leaf Miners. The larvae of some insects burrow themselves in leaves and eat the soft layers inside. The white or silvery trail left is the mine or path being made by the growing larvae. Be warned that the mine is filled with frass (insect poop). So eat greens, such as lettuce or spinach, that show any signs of leaf miners at your own risk.

Killing leaf miners is not easy since they are protected by the leaf itself. Therefore, any spray pesticide (which I don't recommend anyways) will be ineffective. In this case control through other means is necessary. Removing affected leaves is recommended, however, not necessary unless you are eating the leaves (think spinach or lettuce). Nature, in its awesome wisdom, has provided a means of controlling leaf miners; parasitic wasps that preys on this larvae. If you are lucky to have some of these in your garden you may not even have to do anything.

Have you had leaf miners in your garden? If so, let us know what you've used to control them.