Monday, October 7, 2013


Well, after doing well  for two weeks with a determination to post twice a week, I faltered.  Nothing to do now but make a new determination, and continue.  I think I'll try for 1 post / week, and reevaluate at the end of the month.  6 weeks or so ago I sort of ground to a halt - not just with the blog, but all my writing - and I really don't know why, unless it was the difficulties I encountered with trying to put photos into a longer piece I'm writing, a guest blog about sanseveria.  Things like 'why is this so difficult' and 'why am I having such a hard time' and 'I need a new computer' and 'I need to win the Lottey'.  Then 3 weeks ago our cat Mickey, whom we've had for 15 years, had a heart attack, and the whole week was consumed by anxiety - would he get better, was he suffering, will he eat, will he drink, would we have to make the decision to let him sleep.  Took him back to the vet Tuesday, they gave him intravenous and some more medication, but he died in his sleep that night.  Now a new yellow lantana bush is growing in our backyard.

After that I went up to Pennsylvania for a high school reunion, driving with my brother who hadn't been up there since '84.  The planning for (app2600 mi round trip), accomplishment of, and recovery from that excursion has brought me up to current time.

Without further ado, then, here's another short video

Well, thanks to the evil wizards at Google, here will go another video if you cut and paste the link into your browser.  What used to be a simple select and click to put a video into a blog post now involves code embedding and menu locations that I haven't been able to locate yet.  So until I can solve this latest puzzle, or some kind soul will volunteer to enlighten me, it's cut-and-paste.

                          SPECIAL CARE FOR LOW LIGHT PLANTS

Very low light plants need to be treated with extreme care in watering.  You need to  find the balance between the amount of moisture the plant needs to support its slow life rhythms,  and the amount of air it needs to keep its roots from rottiWellng.   Remember, plants in low light just aren't using very much water.  If roots stay damp for long periods of time, they begin to rot,  and eventually the plant will die.  Plants in low light need to become fully aerated (80%aer) between waterings; some even need to reach the bone dry stage.

In general, when watering plants in low light, use only 2/3 the amount of water you would use on the same plant if it were in higher light.  Any water that collects in the liner should be siphoned off after an hour or so.  If the plant cannot tolerate even this level of moisture - if you start to see the over-watering signs of brown tips on the leaves - allow the soil to reach an even higher level of aeration, and/or reduce the amount of water added by 1/2.

While in most cases you don't want a plant to get bone dry,  sometimes in very low light this is exactly what has to happen.  The critcal factor is the amount of time the soil stays that dry.  For most plants, a few days at 90% - 100% aeration  is all the roots can tolerate before some moisture is required.  Not too much, though;  this is the only time you should use the  "small sip" watering technique.  The objective is to avoid any real  run-off, yet to provide enough water to moisten the entire root mass, and to maintain the moisture level at 20 - 30% for a couple of weeks.

Another tricky thing about plants in very low light is that they often don't show damage until it is too late to save them.  The sanseveria (mother-in-law's tongue, snake plant) is especially famous for this.  By the time you see some brown tips on the leaves, or notice that one or two of the leaves are getting soft at the base,  the roots are already wrecked.  Many people, when they see such signs of  over-watering, will cut down on the water as advised;  when the plant keeps getting worse,  and finally dies a few months later,  they are completely confused, and conclude they just can't keep plants alive, etc.

Such confusion can be avoided by testing the soil moisture, all the way to the bottom of the pot, before each watering.  If you find a sansie, or any very low light plant, too wet,  move it to a place with as much light as possible, without burning the leaves in direct sunlight of course, and let it dry down to 80-90% aeration without adding any more water.  This may take awhile,  several weeks even.  Once it has reached this level, you can move it to a darker spot if you wish, and continue with good watering practices as outlined above.

                            SPECIAL CARE FOR HIGH LIGHT PLANTS

Plants in high light locations also require some special strategies.  Because of the higher light, their metabolisms are running at a high pace, and they have increased water needs.  The main objective in watering them is to make sure they don't run out of water before your next visit, but still have an opportunity for their roots to reach the recommended %aer.   If you're on a weekly schedule,  leave a run-off of at least 3" in the liner; a two-week schedule will require a 6" (or totally filled) liner.  This is why you'll want to use the deep liners if you have any high light plants.

If you're not familiar with the plant, the wisest course is to fill the liner the first time you see it.  Don't forget to count so you know how much water it takes to do this.  If all the water has not been used by the next visit, you can make the necessary adjustments, coming gradually to the amount of water that is needed to sufficiently hydrate the soil, while allowing the roots to be sufficiently aerated.  You can take several weeks, even a couple of months to do this, because the high light levels allow the plant to be much more tolerant of wet soil than if it were in low light.

In the unlikely event that the filled liner does not provide enough water for the plant for the duration of your schedule, there are a  few changes you can make.  First, you can remove the liner and set the plant straight into the decorative container,  allowing you to pour in a lot more water.  Second,  you might need to put the plant into a larger pot, with more room for roots and soil  - more about that when we discuss roots and stress.  Finally, of course, you may just move the plant to a lower light location.

End of excerpt from The Color of Your Thumb Has Nothing To Do With It

Watch for the launch of website, on which the full text will be available for purchase, as well as the full video version of the text.

(By Marlie Graves)


  1. Hi Marlie, couldn't figure out how to contact you on houzz, so here I am, it's me Sara who writes about houseplants on Houzz. I have a small favor to ask, would you be willing to help me out by trying to identify plants in photos I find on houzz for the articles I write? While I am a houseplant lover, I'm certainly not a professional horticulturist, so I could use a more trained eye now and again.....have tons of photos of things I think are ficus, but not 100% sure about some of them, for example. Could I give you permission to view an idea book of questionable plant photos on houzz for your input? I'd really appreciate your help! To return the favor I'll try to include professional advice from you now and again in articles. Just do make the link to your blog clearer so folks can follow you there! Oh, please contact me at thanks so much!

  2. I am so sorry about your kitty, he was so pretty. I am really enjoying your videos and advice. After reading everything there is to read about various plants I find your videos give sound advice in an easy to understand way that just make things click better in my mind. Thank you so much for sharing.