Plants are NOT toxic. In fact sanseveria is used medicinally in some places. The fact that slugs and snails eat the leaves to no end is surely a clue that these plants are not toxic. There are some plants with very sharp tips and spine tips that pose more danger than consumption of leaves or roots. BTW elephants do eat this as I have seen them relish these when ever they can sneak a few leaves with their trunks. I bet the spine tipped adaption is a way to deter these relished plants from being eaten. I have seen wild pigs eat them to the root and they don't appear to be sick from eating massive amounts of this.This was the common S. laurentii variegated forms.

MsGreenFinger GW(8 Ireland) I didn't base my post on scientific research. But I did look up articles about 'air purifying plants based on a NASA research' which are actually the most common house plants. (Palm, spider plant, Sans., english ivy, peace lily, boston fern etc) Maybe it does matter what kind of plant one has, how many, what size and how fast they grow. But I am sure, having a dozen large specimens in your home will make the air quality better, just as they make the life quality better. You also can read this interesting aticle: Can House Plants Solve IAQ Problems? The idea of common plants solving IAQ problems is attractive. Most people like having plants in their homes and offices and in the hotels, stores, and public buildings they visit. However, important questions exist as to whether plants can actually affect indoor air sufficiently to warrant their use as air cleaners. Can House Plants Solve IAQ Problems-2.pdf (PDF document 38Kb) This is from this article: To date, advocates have not reported the results from actual field tests. One field study was begun and failed, according to a strong advocate of the interiorscape approach to IAQ control. Stuart Snyder is the president of Aqua/Trends of Boca Raton, Florida, a firm that sells irrigation systems for interiorscapes. He offered his explanation as part of a 13-page letter to Robert Axelrad, Director of EPA's Indoor Air Division. Responding to what he calls EPA's criticism of the NASA work, Snyder wrote, “In many ways small systems are better able to isolate factors, and more clearly define mechanisms at work.... Larger environments are too subject to conflicting variables. Real life, field studies with their complex dynamics are also valuable, and should be implemented at later stages of research -- they are however, more difficult to accurately stage and evaluate” Snyder continued, “Scaled up studies must be made at some point. Associated Landscape Contractors of America have already attempted a controlled study in an office building. It failed as a study because of these difficulties.” The office-building study was done for over a year under realistic conditions and with as much control as can be achieved in a field study, There was no indication that the presence of plants had any measurable effect. HBI Inc., which conducted the study, reported virtually no effect of plants on the VOC concentrations. John R. Girman (Chief of the Analysis Branch at EPA's Indoor Air Division) has prepared a memo that details some shortcomings of the NASA study's claims for the efficacy of plants. The memo was included in correspondence between Axelrad and Snyder. Girman's memo responds to some of the technical issues presented by Snyder and other advocates of IAQ control with house plants. The memo's title is “Comment on the Use of Plants as a Means to Control Indoor Air Pollution,” (undated.) Girman analyzes the notion that NASA research shows plants are effective at removing indoor air pollutants at realistic concentrations and time frames. He calculates that at the most favorable conditions, it would take 680 plants in a typical house to achieve the same pollutant removal rate Wolverton and his colleagues reported they achieved in the test chamber. However, scale-up considerations are also important. It appears that the average chamber volume used in Wolverton's tests was 0.5 m3. This means the results must be appropriately scaled-up for use in a larger environment to allow for differences in volumetric loading (the number of plants per volume of space). This does not appear to have been done. The volume of a typical house in the U.S. is 340 m3 with a floor area of 139 m2 (1500 ft2). Thus, the recommendation that one plant be used per 100 ft2 implies the use of 15 plants in a typical house. [ALCA recommends 1 plant per 100 ft2. Wolverton recently told us he now recommends 2 or 3 plants/100 ft2, but he says “he is “just throwing a dart."] This would provide for 340 m3/15 plants or 23 m3 per plant, not 0.5 m3 per plant as in the chamber. This means that each plant would have to clean 46 times more volume than it did in the test chamber or, as would actually happen, it will clean the larger volume less effectively. To be more precise, each plant will have a pollutant removal rate which is only 1/46 of the rate it would have in the chamber, i.e., only 0.002 h-1. Thus, plants at the volumetric loading recommended would be expected to contribute relatively little to pollutant removal in any indoor environment with typical ventilation To achieve the same pollutant removal rate as realized in the test chamber, one would need to have the same volumetric loading, i.e., 680 plants in a typical house (340 m3 divided by 0.5 m3 per plant). This does not seem practical and this forms the basis for concern that adequate and realistic scale-up considerations are necessary before the use of plants can be recommended as a means to control IAQ. Similar concerns apply to the use of plants to control IAQ in office environments. It is hardly surprising that the attempt to validate the test chamber results by Associated Landscape Contractors of America did not provide measurable success ellenr22 - NJ - Zone 6b/7a(6b/7a) another option would be to not pollute the earth, the air. I agree with you but people need to vote for the right people in the elections to do that.

I wonder why they said sphagnum and not peat. I wouldn't use sphagnum for anything but a top dressing. There are many plants you can grow semi hydro but Sans isn't one I'd try. I wouldn't use sand either. I have never had luck with sand as a soil additive. The particles are too small and compact. When I did use sand it was the only time I had cats interested in my plants.

I don't grow many of these, but when mine became a tangled ball of roots like this I just broke each cluster apart and let them dry out of soil for a day. Then potted them in their new home. They seem to be doing well as I find these plants impossible to kill. Sometimes they sit without water for months when I forget / ignore them and still look perfectly fine, not to mention they seem to grow like weeds. Also, you may want to check out the Sansevieria forums here on GardenWeb.