Lux Your Plants

Light and water are essential requirements for healthy plants with light as the first priority. Without adequate light the plant will die and there's no need for water. This is about the most important first step you can take to provide adequate light and end Black Thumb Syndrome (BTS).

Use a light meter to measure the light in your indoor space to determine if you have enough for the plant(s) you wish to maintain.

Forget about window direction. Using window direction to judge light is advice usually given by outdoor gardeners and horticulturists with insufficient indoor plant experience. They typically don't understand the vast difference between indoor and outdoor "shade".

You may be familiar with foot-candle light measurement here in the U.S. Most of the world, however, measures light in lux, which makes more sense linguistically.

Whether you measure in lux or foot-candles do yourself and your plants a favor by buying a digital light meter. It’s a wise decision to buy one if you count the cost of your plants and your time.

Once you have a meter you’ll find that a difference of just one foot in location can mean the difference between a healthy and sick plant.

It's a waste of time and money to spend six months killing an indoor plant because there just wasn’t quite enough light. If you’re ecologically conscious, also think about the energy used to produce the plant that was wasted unnecessarily.

What does a digital light meter cost? Not too many years ago, you’d need to spend a hundred dollars or more.

Today you can buy a digital lux meter online on eBay for about $35 including shipping. You can now eliminate the importer and buy direct from sources in Asia. There are “Buy it Now” lux meters available directly from Shanghai, Hong Kong, and Tokyo. You can also bid on one from Sacramento, CA starting at $19.00 (without a case or light sensor cover).

My pick would be the one from Shanghai with a padded storage case and light sensor cover. I have very positive experience buying on eBay however no experience with this particular seller. I'd have no reluctance to buy one here but I already have six light meters.

Read the following about lux measurement and then look at the photo above. You'll then understand that a lux meter is really a combination lux and foot-candle meter. All you need do is move one decimal point to the left in your head.

The meter is reading 276 lux or about 27 foot-candles. That's close enough for indoor plant work.

It's not, however, enough light for the majority of indoor plants. So, don't put a plant there! That bit of information could easily save you the cost of the digital light meter.

Read a lot more about indoor plant light and lighting here.

Lux versus footcandle (from Wikipedia)

One footcandle = 10.76 lux. The footcandle is a non-SI unit of illuminance. Like the BTU, it is obsolete but it is still in fairly common use in the United States, particularly in construction-related engineering and in building codes. Because lux and footcandles are different units of the same quantity, it is perfectly valid to convert footcandles to lux and vice versa.

The name "footcandle" conveys "the illuminance cast on a surface by a one-candela source one foot away." As natural as this sounds, this style of name is now frowned upon, because the dimensional formula for the unit is not foot • candela, but candela/ft2. Some sources do however note that the "lux" can be thought of as a "meter-candle" (i.e. the illuminance cast on a surface by a one-candela source one meter away). A source that is farther away casts less illumination than one that is close, so one lux is less illuminance than one footcandle. Since illuminance follows the inverse-square law, and since one meter = 3.281 feet, one lux = 1/3.282 footcandle = 1/10.76 footcandle.

In practical applications, as when measuring room illumination, it is very difficult to measure illuminance more accurately than ±10%, and for many purposes it is quite sufficient to think of one footcandle as about ten lux.

Sub-irrigated Desert Garden

Click to enlarge and read more details. Okay, you got me. I don’t know the names of all these plants. I do know, however, they’re happy in their sub-irrigated soil based media inside a microwave food cover. Witness the cute red flower and the healthy look of all the plants.

No, these are not growing in special cactus and succulent soil mix. They’re growing in the same potting soil mix as all the other plants in the Greenscaper Consumer Lab. This includes the moisture loving Spathiphyllum (Peace Lilies). It is the commonly available Supersoil (13 Western US states).

I can hear the chorus of horticulturists and gardeners and the cry of “you can’t do that!” Oh yes you can and as always you do not need to take my word for it. It’s easy enough to prove it to yourself.

They’re also going to tell you that sub-irrigation which they erroneously call “self-watering” is only for moisture loving plants. They conclude this only because they foolishly maintain water at too high a level in the reservoirs of these planters.

Using measured sub-irrigation, you can easily feed a small amount of water to desert type plants with pipette like precision. This cactus and succulent bowl consumes just 1 ½ ounces of water per day, just about all of it going to the plants. It isn’t wasted down a drain hole or in moistening the upper soil level where there are little or no roots.

Just know that all of the “special” soil mixes you read about on so-called “houseplant” forums are necessary only because of drench and drain top watering. These mixes are used to counteract the weaknesses of drench and drain watering that is difficult to control, compacts the soil and leads to a lot of over watering.

Using measured sub-irrigation, the soil media is merely to support the plant and facilitate capillary action. There is very little soil compaction and the water is evenly distributed much like a perfectly baked cake. Try it. You and your plants will like it!

Tabletop Tree

It may not be the star attraction, but it's nice to see this tabletop tree at least on the stage of a professional interior design. What a beautiful home kmr2069 has created. Take a look at a baptism party setting for his baby daughter...here, here and here. It must have been a memorable celebration.

I regularly search through hundreds of Flickr pics with design tags and find very few with plants in the photo. This was one of the rare finds in the interior design pool.

I have no idea how this little tree is maintained or if this is its permanent location. It doesn't matter. It's a welcome relief from the mainstream "houseplants" I encounter on the web, most of them in unadorned plastic grower pots or outdoor clay pots sitting in saucers. I often wonder if gardeners show photos of their kids or animal pets that look as unappealing.

It's no wonder most professional interior designers and architects are reluctant to include indoor plants in their portfolio photographs. That's a sad commentary. Plants in buildings deserve a lot better.

Ralph Waldo Emerson Quote

Ralph Waldo Emerson said: "People only see what they are prepared to see." and:

“Whatever course you decide upon, there is always someone to tell you that you are wrong. There are always difficulties arising which tempt you to believe that your critics are right. To map out a course of action and follow it to an end requires courage.”

If I didn't believe what Emerson said, this blog would have ended a long time ago.

Peace Lilies and Remembrance

Click to enlarge. It’s an appropriate day to talk some more about Peace Lilies. Spathiphyllum are one of the most popular indoor plants. Because they are often received as memorial plants, people naturally have a strong emotional attachment to them and don't want to see them die.

The Peace Lilies in the foreground were purchased as 4” plants growing in soil. I converted them (hydroconverted) from soil mix to clay pebble sub-irrigation (aka hydroculture) while they were in full bloom about a month ago (August 7). The plants have shown absolutely no sign of shock from having the potting soil carefully washed from their roots.

The one on the right front has already put out a couple of new flowers. You can see one of them in the center of the photo coming off at an angle.

Even though I’ve found Peace Lilies to be perhaps, the easiest plants to hydroconvert I would recommend practicing as I did on one or two 4” plants.

Incidentally, I purchased the plant in the middle as a 6” plant. When I hydroconverted it I discovered that it was a recently potted up 4” plant sold as a 6” plant. There were no roots in the new soil surrounding the 4” pot size plant. It’s interesting what you find when you unpot indoor plants immediately after purchase.

I regularly read pleas for help from “black thumb” (non-gardener) Peace Lily gift recipients who don’t know anything about indoor plants. This information is for them.

• Be sure to use sub-irrigation, either soil or expanded clay pebble media. Personally, I would convert all the plants in the Greenscaper Consumer Lab to hydroculture. I do not because I want to continue testing soil based plants since they are the only choice in the U.S. “houseplant” market.

• About flowering, the white (or green) “leaf” is botanically termed a spathe. The white “corncob” is the flower.

• Plants with flowers need significantly more light (to flower) than plants grown just for their decorative foliage. Flower production requires much more energy than foliage production. The energy comes from light.

• Even with adequate light and precision sub-irrigation, your gift plant will not likely bloom again in such abundance. Greenhouse growers use chemicals such as gibberellic acid to induce flowering. This is not feasible for indoor plant maintenance in your home or office.

On Your Desk for About $30 Complete

Click to enlarge. Here’s a sure cure for Black Thumb Syndrome (BTS) for about $30 complete—plant, clear glass bowl and compact fluorescent desk lamp. Wouldn’t this look nice on your workspace wherever it is? With this lamp, you don’t need to worry about having window light.

The natural light of this lamp will provide cheer for both you and your desktop plants during the coming winter. Do yourself a favor and ignore the advice to move them outside during the summer. It is simply bad advice.

Hurry to Costco. There’s a $5 rebate on an already affordable price for the 27-watt lamp. The output is equivalent to a 150-watt incandescent bulb. The net price is $21.99 after the rebate. Read more about the lamp here.

The lamp provides about 500 foot-candles, enough to support a flowering Spathiphyllum. I converted this new plant to expanded clay pebble sub-irrigation (aka hydroculture) in full bloom.

If you’re going to convert from soil to clay pebble media, I would recommend waiting until the flowers have expired. However, I wanted to photograph it in full flower. I’ve done this before and expect that the plant won’t even notice the hydroconversion.

You can even maintain high light requirement desktop trees like Ficus benjamina or Schefflera arboricola (dwarf Hawaiian Schefflera) with this lamp.

This is modern digital age indoor deskscaping. The plants need for light and water are met by modern methods. Anyone can cure Black Thumb Syndrome with this setup. Don’t let anyone tell you it won’t work.

If you have questions or need help, don’t hesitate to email me at bobhyland [at] insideplantslive.org

Some Things Don’t Change

The following is from a newspaper article of a few years ago. Who knows whether Egyptian physicians were warning about the same thing?

If you're striving to gain the claimed air cleaning qualities of indoor plants you might think some more about the potential problems created by drench and drain top-watering.

Coupled with insufficient light this arcane watering practice is without doubt the leading cause of soil borne mold problems, fungus gnats and dead and dying houseplants. I read about it every day when doing my research.

MALARIA FROM PLANTS. Ague May Be Contracted from the Soil In the Window Garden,

There is an undoubted prejudice against house plants in the bedroom, which has not seemed to be justified by anything that has been proved against the plants. Most of such popular ideas, however, embody a truth, and it is not wise to ignore them. It has been recently found that malaria has been propagated among persons sleeping in a room in which plants were growing in boxes filled with malarial soil.

Several cases of this disease in winter have been traced by physicians to this cause. The germs seemed to thrive in the heated air of the house. When we remember the source from which the house plants are obtained and the common use of rotted earth from often malarial swamps in preparing the soil, it is surprising that this complaint has not been made before

It is quite possible to have too many house plants. A few blooming house plants, are a pleasure in living rooms. It is however the practice of some families of filling all the sunny windows with bowls of dark earth for the cultivation of flowers during the winter and spring months. It is not to be commended.

The most essential thing in any home is the health and comfort of the members of that home. If out of the sunshine, often the flowers must be given up, however delightful their presence is. There is no such objection to a conservatory built especially for the accommodation of plants, though it is possible to introduce the germs of malarial earth even in this case.

The objection to flowers in many houses is that they may occupy the sunny windows that the members of the family should sit in and enjoy. During a great deal of their time of growth, house plants are not ornamental, but simply a promise.

While summer plants are resting from growth, it is better to keep them in a well-lighted cellar than upstairs, where they are not often ornamental and are certain to be in the way. This applies to geraniums, begonias of some kinds and to the vast majority of the summer blooming plants, which must be taken in during the winter.

Curious about the date of this article?

It's about 107 years old from the The Trenton Evening Times on Monday, March 27, 1899 (Trenton, New Jersey)

Maybe it’s time to take a fresh look at so-called “house plants” and “indoor gardening.” What do you think?

Note: *The text above was extracted from the image using Optical Character Recognition technology and may appear disorganized. Members enjoy access to full size newspaper images as they were printed and therefore in most cases experience 100% readability.

Wet Soil - Allergies and Mold

This is an article about indoor allergens. Those who think their top-watered “house plants” are virtuous should think again. Their green plants may not be as environmentally green as they think.

Contrary to popular belief, Fawcett said, bringing flowering plants inside will not aggravate allergy symptoms. However, she said, indoor trees could.

"I think the biggest issue in indoor plants is the amt of soil you pot those plants in because then you tend to over-water, and they grow mold spores," she said.

If you think this is a quack opinion read the rest of the 646,000 Google search hits on the subject.

Drench and drain watering of indoor plants is simply a bad idea. It's for outdoor gardening and not good for your indoor environment.

Remember that the soil surface is always dry when you provide water to your plants by measured sub-irrigation. If there's no moist soil, there's no environment for the propagation of mold. There's also no environment for the propagation of annoying fungus gnats.

Green Recognition

It was nice to be recognized in the company of the plants-in-buildings website and retired NASA scientist Dr. Bill Wolverton both highly respected sources of information about indoor plants.

You won't find any environmentally unsound "drainhole" advice on this or the other two referenced sites.

Click here and scroll down to Technical Guide 2: Plants and Indoor Air Quality Sources.

Excerpt: Technical Guide 2: Plants and Indoor Air Quality With most people spending up to 80% of their time in indoor environments, be it at home, in the office, at school or university, it’s becoming more and more important to ensure our indoor environment is a healthy place. This is even more necessary as buildings become increasingly air tight and ventilation systems become closed loop. The term “building ecology” has been coined to describe the interaction between building environments and their occupants (Levin, 1981). A healthy building is one that does not adversely affect the health of its occupants or the larger environment. An integral factor in this interaction is the indoor air quality of a building. Studies have shown that poor indoor air quality can substantially reduce the productivity and general health of workers in the office environment, with indoor air quality often being more polluted than outdoor air. Our appliances, decor, cleaning products and fixtures contain enormous amounts of potential polluting substances, so it is very important to ensure the internal air quality of all buildings is healthy and clean.

Back to School Advice

Good advice here, but whatever you do don’t listen to your mother about how to water them. She’s probably still trying to get them to drink compost tea and eat granola.

Be sure to use digital age plant care methods and help end Black Thumb Syndrome (BTS) forever.

So— what have you done today to help end BTS?

Along with the iPod, laundry bag and laptop, take a plant to college.

Why? It might humor your parents. They're nostalgic. They remember the 1970s, the heyday of dorm houseplants.

But this is really about you. Having a plant gives you good vibes. It's a feng shui thing.

Plus, studies by NASA researchers indicate houseplants help clean indoor air. You don't have to be a rocket scientist to appreciate how important that is in a dorm room.

So go green, even if you're really going purple-and-gold, or whatever school you're heading to.

Plants Where we Work

Plants at Work (PAW) is the name of an interior plantscaping industry website. I’ve always felt it should be a more inclusive name to encourage the use of indoor plants wherever we are.

Appropriate to Labor Day weekend, this post is about plants anywhere we work. I surfed through a slide show of all the photos in the Annotated Work Space group on Flickr. This was one of the few photos with a visible plant.

Monica , the owner of the work space is in Portugal. Two things were interesting to me. Even though the Dracaena marginata is center stage it isn’t annotated. Two, I wonder if she is using the glass globe to sub-irrigate it. I can see what looks like water residue on the glass.

As of this date, 564 members have posted 798 photos from a wide variety of places where they work. These are not just offices, as you will see if you view the slide show. Some of them are quite funny.

Of these 798 photos, I found about a dozen and a half with a plant visible in the workspace. That’s only about 2%. Obviously, this isn’t a scientific survey but it says a lot about the use of indoor plants in our lives.

We can likely attribute this to Black Thumb Syndrome(BTS).

Interior Plants Consumer Survey

Interior Landscape Business reported on a recent consumer survey conducted by Project Evergreen. The results are not surprising considering the low level of interior plants publicity I find when doing research for this blog.

Summary of consumer awareness turned up the following points:

• 70 percent of the respondents were not aware that interior plants save air conditioning costs before seeing the survey;
• 70 percent of the respondents didn't know that psychologists have found access to plants and green spaces provides a sense of rest and improves worker productivity;
• 70 percent of the respondents weren't aware that employees with an outside view of plants experience less job pressure;
• 65 percent of the respondents didn't know that employees with an outside view of plants experience greater job satisfaction;
• Half of the respondents were aware that trees, shrubs and turfgrass remove smoke, dust and other pollutants from the air; and
• 80 percent of the respondents were aware that well-placed plantings offer privacy and tranquility by screening out busy street noises.