October 19, 2006 2:31 PM PDT

Sensor battles senseless houseplant death

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September 13, 2006
Plants can't bark. That's why Matt Glenn founded PlantSense.

The San Francisco-based start-up has developed a 10-inch, stake-shaped sensor that obtains information about light, moisture, soil composition and other factors that can affect plant growth and health. The sensor is placed a few inches into the soil and connected to a computer, via a USB interface, where it downloads the information to PlantSense's Web site.

PlantSense can then tell users what they're doing wrong (too much sunlight, not enough fertilizer, etc.) as well as provide recommendations on what plants might grow best in a particular microclimate in a home or garden. Subscribers to the site can also keep records of the health histories of various plants and microclimates in their house and yard on the site.

"What we have developed is a plant lifecycle development platform," he said, co-opting some of the buzzwords he likely used while working at Cisco Systems and Xircom.

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Killing plants is one of America's favorite pastimes. In 2003, Americans spent $18 billion on indoor and outdoor plants, not including grass. That's $160 per household, on average.

Roughly 14 percent of plants die in the first few weeks after being bought, and another 18 percent die within five months. That 32 percent mortality rate partly explains why Americans also spent $23 billion on fertilizer and plant food in that same year.

A big part of the problem is that most Americans have moved off the farm and into cities and suburbs years ago. Plants are also not great communicators: If a dog or cat is hungry, they will let their owners know; plants are more subtle with their signals.

The PlantSense stake will likely sell for around $49.95 when it comes out in the fall of 2007. Buyers will be able to access the PlantSense Web site for a year. A second year's subscription will cost about $20. Buyers only need to buy a single stake to test all of their soil. The battery in the stake lasts about a year.

That price range is in line with what consumers would expect to pay, according to Glenn. He polled about 200 consumers about whether they would like a product like this--81 percent said yes, and the median purchase price was about $50. An informal poll (conducted by the author at a lunch event) reflected similar results.

Glenn came up with the idea in January 2006 while getting a haircut and staring at some dying plants in a window. He asked his hairdresser why they were dying. She said she didn't know, but that it always happened.

By April, a prototype had already been designed. Initially, the PlantSense stake only provided recommendations on what kind of plant might thrive in a particular microclimate in the home or yard. A University of California botanist, however, told him he should add plant diagnostics for sick plants. To the sensor, those two jobs are identical.

The technology for sensing moisture in the soil, he added, comes from the same people who designed software for soil composition sampling on the Mars rovers.

Right now, the company is trying to land venture funding. It has retained a retail expert who worked with iRobot on the Roomba to craft a marketing strategy. In the first phase, the device will be available from the company's site and specialty retailers.

Over time, PlantSense will try to get onto the shelves at big-box retailers. Ultimately, the company would like to get plant growers to put a code on their plants, so that a consumer could get a soil/light/moisture score on a particular plot of land in their yard and then buy a plant with a corresponding rating.

But won't large retailers like Home Depot recoil against such a device? They make money right now by selling new victims to homeowners, after all. It turns out the big-box retailers may actually like the idea, according to Glenn. According to retailers, if people fail at gardening, they stop doing it; if they succeed, they buy more plants.

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Something's wrong with the calcs!
It mentioned that in 2003, Americans spent $18 Million dollars in plants at an average of $162 per household? There are about 100 million household based on latest survey, and perhaps in 2003 it was not far off. So at $162 per household, that would be $16.2 billion at least, not $18 million, no way!

plus how can you spend $23 Billion in fertilizer and chems to feed $18 million worth of plants?

Perhaps, there was just a typo, it meant $18 billion.
Posted by Joe Real (1217 comments )
Reply Link Flag
Thanks for the correction.
Wow, it was corrected in under 30 seconds of my post!
Posted by Joe Real (1217 comments )
Link Flag
A correction
Hi All,
A couple of notes...

According to the USDA it is an 18 Billion dollar market. I think that the writer missed the mark there.

I've tested the cheap pH sensors and found the same thing. We are addressing this via additional 'tops' that you put on it. This is also licensed technology that is very accurate.

Posted by Matt_glenn (3 comments )
Link Flag
perhaps minimal impact.
Based on my speculations, the sensors would be neglected also. I have yet to find a decent sensor that can measure properly soil moisture around the root zones and soil pH (the second major problem, but the most problematic to determine). There are plenty of cheapo pH sensors that you can buy for $4.99 but they don't work. The light sensors are cheap, as well as moisture sensor. Accurate pH meters on the other hand are at least $299.00 So I was wondering the accuracy of fertilizer application when pH is unknown.

The most common causes of death would be moisture stress (under or over depending on plant type) and light levels. Next to that would be nutrition which is strongly affected by pH and plant cultivar.
Posted by Joe Real (1217 comments )
Reply Link Flag
One more item
the 23 billion is not just for fertilizers. It is for Plant Care products - watering cans, sprinkler systems, lawn mowers, etc.
Posted by Matt_glenn (3 comments )
Reply Link Flag
Don't Take This Away!
"Killing plants is one of America's favorite pastimes."

Yes, that's right! And why take it away from those of us who enjoy it? ;-)

On a more serious note, I have to wonder why I must pay a subscription fee after the first year. Why not sell me the software that is undoubtedly used at the other end (you don't believe that a real human being is analyzing your plant growth, do you?) instead of making this a subscription model?

mark d.
Posted by markdoiron (1138 comments )
Reply Link Flag
Good Question
I am not sure about the subscription fee yet. I've been told by a few investors it is something that must be done to get funded.

I'm hoping that once I produce the product there is enough uptake to where it isn't necessary.

Posted by Matt_glenn (3 comments )
Link Flag
Headline is confusing
The problem is 'senseless'. What does it modify...death or
houseplants? Death as in wasteful or houseplants as in lacking
senses (touch, taste, smell, etc.)? Either way it's unnessary, unless
there are houseplants that have senses (and therefore could,
perhaps, monitor their own condition, or are there houseplant
deaths that make sense as in euthanasia for a terminally ill
Posted by Mac User Too (172 comments )
Reply Link Flag
But I want one for each plant, and have them wirelessly connect directly to my computer and provide a "dashboard" that shows which plants are in need. Believe me, I've replaced half my plants with plastic ones. I NEED this device!
Posted by ss_Whiplash (143 comments )
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