eGarden © 2006 Ed Mues

From The Garden of Ed. Submitted for publication in The Towne Crier on September 6, 2006

Diagnosing Houseplant Problems.
(Adventures with Flora continued...)

When Flora's in the house, we expect all kinds of rewards. Cleaner air to breath, a more peaceful indoor ambience, a melding of the verdant outdoors with that contained inside. Blossoms unexpected and most welcome, colors that surprise, especially as the outdoor season's finish is more of the foliar variety, glorious as it is, but not long lived. Soon to come is the bleakness that accompanied late fall and winter, starkness in gray light, and, in some years, a lasting cover of whiteness occasionally recharged by not infrequent snow events.

Houseplants lift the spirits in winter as do some fresh flowers or a blooming plant. The sharp contrast with the outdoors enlivens us, rekindles thoughts of the coming season and the real turn-around, as far as day length is concerned, the "first day of winter". It is the first day of this period that is longer than the day before. I sometimes think of renaming the seasons or having more than four. Isn't the "first day of winter" a misnomer? The next day length is longer than the previous.

Continuing to follow up on my searching for answers to some of Flora's problems, we look closer than anywhere else: Inside the house, or perhaps on the porch or the deck for a few more weeks before cold weather and frosts threats coerce us to rescue them and bring them inside, hopefully after a close examination for insects or unhealthy looking foliage. Remove these out of doors as soon as seen. A decent cleaning with a spray bottle of gentle soap and slightly warm water solution will have then clean and shining and ready to assume their respective assigned spots in your interior-scape.

This is always a very exciting time for me because I must have plants around in every room in a place where they will nobly survive or thrive. I do not want any casualties. Following on the heels of my previous columns, do you know the common name and variety of your houseplant?

How about the botanical name? Do you know what conditions it prefers regarding light, temperature, moisture, and soil pH? Describe the problem for yourself and don't leave anything out, including when the problem was first noticed, okay? All of this is already providing a wealth of information.

Houseplants are found in a wide variety of containers, all of which should contain a hole or more in the bottom to provide for drainage of excess water. The plant temperature requirements are intuitive as they are tropical or semi-tropical and few will survive, much less thrive, in temperatures outside the range of 55 to 85 degrees F. This is our preferred temperature range, too, depending on our desired creature comfort level.

How long have you had the plant? Clearly, a plant that's been with you for several years is properly cared for and understood, and only problems outside the average might need to be looked into. If you are having a problem with a new or recently introduced plant, care must be taken to inspect carefully to be sure you aren't importing pest problems. Remember, pests are animals (insects in this case) as well as diseases and fungi. Conditions indoors can easily support pests and their ability to survive and reproduce. Be careful about newcomers.

Regular readers of my columns will recall my saying that a stressed plant is a waiting victim, with a reduced immune or defense system. So, the next set of questions are somewhat intuitive and the answers almost self-educating. How large is the pot in which the plant is growing? When was it last repotted? How large is the plant in height and breadth compared to the container? Have you looked at the root system recently? Is there sufficient room for new root growth?

Perhaps the most important questions are: What is the source of light? Natural or artificial? How far from the source? Number of hours of direct light in fair weather? Hours of daylight in poor weather? Natural light from north, south, east, west? How far from windows or source? I've used the "source" word because some spots in a home are just too dark to support a plant without artificial light. These can be put on timers, but too close can scorch or burn the foliage.

In previous columns, I've singled out environment as a most important factor. Each houseplant is living in a micro-climate: One of temperature swings, changing light, humidity and dryness fluctuations, and possible threats of attack from nearby pests. So, along with the above mentioned light needs, plants have moisture needs that are almost exclusively correlated with light and temperature. As our plant grows, we are seeking as near a perfect balance as can be obtained between moisture, light, and temperature.

If we accomplish this, there is near zero stress on the plant. If it contracts a pest problem, it is likely that it will hang on until we (constant observers that we are) discover an attack, resolve the conflict, and restore our plant to good health and vigor.

This is not meant to be a winter column. It is just that we are more closely attuned to our houseplants when they are nearest at hand. Houseplants have summer problems, too. An important question rises to the surface. When is the best time to be feeding houseplants? The answer is "When they are actively growing." This may well be answered "Spring through fall." But, not in every case, believe it or not.

Some are able to weather their favorite houseplants outdoors in dappled light, which they seem to relish for most of the summer months. Outdoors they experience warm days and cooler nights. This is actually closest to their natural habitat. Even sun-loving plants seem to compromise, accepting longer days in place of stronger light. Some, including my plants and several others I've visited, have such an abundance of excellent southern exposure sunshine in winter, that the reduced day-length and occasional darker skies has reversed the growing cycle, as if our collections were in the southern hemisphere and actively growing.

So, feeding of houseplants should truly take place when they are actively growing, and this might mean summer for most, but might mean winter or spring for others. It's all about location.

Do you follow a watering schedule? Every Sunday? Every Wednesday and Saturday? Are you so dedicated that you check your plant's soil surfaces for dryness or use a probe-like moisture meter that tells more about the sub-surface moisture? This latter is ideal, but maybe a bit obsessive to some. How much water is supplied each watering? Remember that the soil surface of most plants needs to dry moderately so roots can obtain necessary oxygen. Constantly wet soil prevents this, and can lead to root rot, usually fatal.

Do any of the leaves of your plants ever have shiny or sticky areas? This almost always indicates the presence of the waste products of a sucking insect. It is known as "honeydew". The most likely suspects are mealy bugs, scales, aphids, spider mites, or white flies. These had to be brought into the house.

Aphids will hitch a ride on your hat or tee shirt. Bright yellow on your clothes attracts these and white flies. Aphids and white flies are noticeable with every contact you have with your plants if you look closely and pay attention. No so with scales and mealy bugs. These two often reside in leaf axils, and the scale has additional camouflage as another way of escaping detection.

Do you ever notice any fine webbing over the leaves? Spider mites are usually found on the back of the leaf and they are very small. The leaves begin to appear stippled with small yellow dots. A spray of water will usually reveal the fine webbing these pests weave and use as a matrix.

Would you characterize the air around your plants as humid or dry? Kitchens and bathrooms are generally more humid, but is the light there adequate to support houseplants? Has any insect control been applied to your plants? Do you keep a record of the brand names and dates applied?

Some plants love fresh air and some abhor even a draft. Do you have a plant that is subject to a regular draft? A frequently opened door or window is a draft source that many plants enjoy but some, such a Ficus benjamina, dislike and will drop leaves in response. You have before you a lot of questions that I hope will enlighten and motivate you to seek answers as well as solutions to problems. Don't hesitate to let me know of your questions and concerns. It's horticulture, not rocket science or brain surgery. The answers are out there, and here.

From The Garden of Ed. Submitted for publication in The Towne Crier on September 6, 2006

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