Watering Houseplants With Science?

Hi. Posting from Scotland. My background is in polymer technology and specifically developing hydrogels for medical, controlled release, biomaterials and sensor applications. My hobby is cooking and growing fresh kitchen herbs which I used to water to a fairly strict regime - although sometimes from above and sometimes from below. My plants did ok for awhile but usually then suffered from overwatering.
I decided that I should be able to control the flow of water to plants using my hydrogels in membrane form. After a few prototypes my invention worked spectacularly well with basil, achieving plants 2ft - 3ft in height! I extended it to using common houseplants like begonia, chrysanthemum, poinsettia, orchids, streptocarpus, hedera, areca, peace lily, gerbora, bromeliad and african violets with similar success.

My invention uses osmosis whereby water diffuses from a reservoir through a hydrogel membrane into a plant container. When the water reaches the soil it dissolves nutrients and salts within the soil to form a solution which in turn creates an osmotic potential across the membrane. This causes more water to be drawn through to balance the relative concentrations either side of the membrane. At the same time the plant is drawing water and nutrients from the soil and "soil solution" through its root system. In effect the plant is controlling the rate of transport of water from the reservoir through the hydrogel membrane. The worry is taken away about how much? and when? to water as all that needs to be done is to maintain water in the reservoir. The plant then maintains the equilibrium. I've gone from keeping only a few plants, mostly herbs, to having lots of plants around my home. I have an african violet that has flowered 10 consecutive times in 4.5 years. I monitor when I fill the reservoir and can now predict when it is about to flower as there is an increase in water uptake. It is amazing how little water the plant uses, especially as it is now about 12 inches in diameter. I think this has been achieved by removing the lottery of feast and famine watering, whether from above or below.

 

Hi Chris.
Sounds perfect for my better half ,who drowns plants because"They looked thirsty" :rolleyes:

So com'on, how do we get some :confused:

Paladin

 

Yeah, lets know a bit more, like how much does it cost, for example.
:D

 

I'm happy to answer any specific questions on the technology.

I've gone from keeping just a few houseplants around my home to having loads. My aunt uses it for propagating cuttings and growing from seeds. She has had success with strawberries and cherry tomatoes! I have even managed to grow a little orange tree from a seed to the delight of my 4 year old daughter. I used a perlite\vermiculite growing medium to do this but I think compost will work just as well. More info etc is available at www.osmogro.com .
Chris

 

Very interested I saw a filmclip on gardners world about 'hydroponicum' in scotland where they are growing produce on a commercial level. as I am limited to space in my garden and would like to increase the range of fruit and veg i grow i would be interested in your system. what i did not understand is how to get oxygen into the roots. I could only think of using an aquarium pump and air stone system. What would you suggest?
Thanks

 

Meggie,
Funnily enough the perlite\vermiculite mix that I used for my orange tree came from the Hydroponicum. I had some interaction with them a couple of years back when they successfully tested their growing media with prototypes of my watering system. It was mostly kitchen herbs that they tested and I did similar tests at home using their "Hydroponicum Gold" medium - it worked really, really well as long as the nutrients were replenished. I have not needed or tried to introduce oxygen into my water reservoirs so I'm not really in a position to make an informed suggestion. I understand that the highly porous perlite\vermiculite mixes 'naturally' hold quite a lot of air\oxygen.

 

Here is a picture of my first African Violet during its second flowering. It was described as "almost show standard" by the UK St Paulia Society. I think this was achieved because my membrane controlled watering method allowed the plant to establish its own happy and dynamic equilibrium. The 10th consecutive flowering has just started. If anyone is interested I can post a chart of the water useage for the 4.5 years that I have had the plant. The flowering and watering pattern and rhythm are quite clear to see.

Chris

 

See below charts of my african violet's water usage since I put it on my membrane osmosis watering system at the beginning of February 2001. I've included an exploded chart with clearer detail of the increase in water use prior to flowering.

The plant was originally about 4 inches in diameter. Its peak size was about 16 inches between the second and third flowerings. As it begins its 10th consecutive flowering, the diameter is about 12 inches. The average leaf size is now smaller and more regular than during the earlier flowerings - there are 4 (maybe 5) concentric leaf rings compared to 2 - 3 rings at the beginning.

I think it is interesting to see how the overall rate of water use has decreased as the plant has grown in size. I guess this is due to the larger plant being able to hold and retain more water in its structure. I think that I am also seeing a pattern of 2 flowerings per season. From beginning to end, flowerings last on average 10 weeks.

I have not used any specialist fertilizers, just regular houseplant Miracle Gro Pour and Feed (capful every 2 - 4 weeks directly into the compost). The plant has been re-potted once.

I have kept watering pattern data on many plants including chrysanthemum, begonia, basil, rosemary, poinsettia, hedera (ivy), small conifer, orange tree (from seed), cyclamen and others. They all show variations in the rate of water use (like rolling steps) but differ from the african violet in that the water use generally increases as the plants get bigger.


Hope this makes sense
Chris

 

Interesting product, ChrisM.

I checked out the w/s but notice it only comes with pots of 13/14cms diameter. I have much bigger plants than this I'd like to try it with. Why no bigger pots?

 

mmd,
I couldn't do all pot sizes from start due to costs. The majority of core line houseplants grown and or sold in Europe e.g. chrysanthemum, begonia, poinsettia, gerbera, african violets, kitchen herbs etc etc come in pot sizes of 13cm or 14cm. These sizes are also good for growing seeds and propagating cuttings. Larger flat-based pot sizes are planned but moulds are expensive. Some larger pots can be made completely flat by removing the "feet". No problem making larger gels. 13 - 14cm pots are also good for becoming familiar with the new and unique technology. Chris

[ 05. July 2005, 07:48 AM: Message edited by: Chris_Moran ]

 

That sounds most logical, Mr Spock!
Best of luck with it! :D