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Need a little help. I have a moisture probe that you stick into the soil to get moisture readings. It has been over a week since I have watered my tropical indoor plants. The reader still says that the soil is wet. The meter goes from 1 to 10 and it flys all the way to the 10 spot (wet),as soon as I plunge it into the soil. It has been humid lately, as it has rained the last couple of days. The humidity level in the house has been between 45 and 60 percent for the last week. Is it possible for the soil to stay that moist for more than a week?

Yup, it is.... but have you checked the batteries in your probe? What types of tropicals do you have? (Got pictures?)

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Thanks for the welcome Patty. I don't think the probe uses batteries. There is no compartment to take out batteries or install them as the back does not open. I believe it works in some other way. Testing it though as shown to me that it is very accurate. I also have some aloe plants that are in very dry sandy soil and it reads them accurate. I am not very good with the difference between the scientific and common names but I will give it a shot. I have a 4 foot Arbicola Capella, a 5 foot Dracaena Massangeana Cane, and two braided plants that are some type of hybrid mixture of Ficus and Philodendron. One is about 3 feet and the other 6 feet. I do not have pictures at this time.

Ah, one thing I forgot. If the meter is showing wet does that mean I should stay away from watering? At one time I was watering twice a week because I thought once was not enough. I know the most common mistake is to overwater so I am trying not to do that. I believe when I thought once was not enough it was less humid around here. Now maybe once a week is too much with the humidity level being higher lately.

As far as I know, your Arboricola Capella likes to be watered frequently during most of the year, & not much at all over the winter months. (I have no idea how house plants know what season it is, but they do!)

Thanks Patty, I will see what I can do about pictures in the future but I am not making any promises right now. It sounds as if you are saying that I could actually go weeks without watering these plants, except for the capella. I must have lots to learn about taking care of these plants.

P.S. I only have gravel on the bottom of my aloe planters. I did not place gravel on the bottom of the pots with my tropicals. I put soil all the way to the bottom. They do have drainage holes though and I do not let them sit in the water. They are taken out of the saucers and placed outside when watered so the water runs through for a few hours before they go back to the saucer.

Jimmy, The symptoms you've mentioned ALL seem to me, to be from over-watering. Which, no... doesn't mean "watering every day", but rather, keeping certain plants wetter than they can handle & not giving them a chance to "rest" between drinks! (If your humidity is high, they ARE getting SOME water!)

It sounds as though you're going to HAVE TO get those plants out of the soil that's keeping those roots too wet, or I'm afraid that you could wind up with root rot! Get some rocks in the bottoms of those pots (at least 2 inches) & get them in a light soil that doesn't hold water well. (If you can make a mud ball out of the soil, you'll know that it's too dense to drain properly, for those types of plants.)

I really don't know what to tell you about the symptoms of over-under watering not showing up for a while... it's probably different with each plant type, & you really have to analyze each of them, individually. Let me do some hunting & see what I can come up with for you, & hopefully, some of the people around here who actually have more experience with the particular plants you have, will pop in & tell us what works for them.

Meanwhile, go next door here, & read what I wrote about my Dracaena . (Be sure to read the archive link there, too. It was VERY helpful to me, in understanding that plant!)

By the way.... I know exactly what you mean, But... I would like to think that THIS is NOT just "one of these sites"! Just keep asking questions, & if that same person doesn't come back & say more, then someone else is bound to come along who can and will explain things better!

The people here on the Garden Forum aren't perfect, but they ARE the best bunch going! Stick around, my friend, & you'll see!

We DO want you be a successful gardener, & to be able to enjoy your healthy plants!

Thanks Patty, I guess you are saying that I can't just wait for the soil to dry out? It seems amazing to me that everything was good for the last couple of months and now I haven't watered in the longest and the soil won't dry. I am going to give it a few more days and hope for the best, if they don't dry I will have to repot. Dang it!

Patty, two things I forgot to mention. First, the soil I used is a high quality potting soil and it is peat moss based. Second, I have a decorative green moss on top of the soil which probably holds moisture in. Everything I have seen on this has said this is a good thing.

OK, you have the right kind of soil in the pot, but it does need to have better drainage.
We might be back to the subject about things not reacting right away. Like anything else, plants will sometimes tolerate less than perfect conditions for just so long, before they can't ignore them any longer. I hope that when you repot, to get the rocks in there, you don't find mushy, water-logged roots that stopped taking in moisture.

JimmyGreen, I don't have experience with your specific plants but I do with Overwatering the result of overwatering <drat>. You don't mention what kind of pot (plastic or clay), but in plastic, plants will stay more wet.
May I suggest, in addition to good stone drainage at the bottom, that when you repot and if you find the root ball is wet, set your plant on some newspaper for a day or two (not exposing the roots to hot sun). This will wick out excess moisture. Definitely repot in a clay pot that breathes.

Can you post pics of your plant?

p.s. I'd believe your moisture meter

Thanks Patty. I hope the roots are ok when I take them out. I think these plants are in pretty good shape right now. I am sure they will be fine. I wanted to add another plant anyway so rearranging some of them in different pots was going to take place regardless. I will do what I can as far as pictures. I actually lost my digital camera on a trip a little while ago so I have not taken many pictures lately.

I repotted two of them. I used the same high quality soil as before and even added a little extra peat moss and a little extra perlite for aeration. I also lined the bottom of the pots with stones about 2 inches high. The new soil before I even water shows a 5 to a 6 on the water meter. I wondering if I even need to water these things at all. If you were going to throw out an estimate, what would you say for watering with a nice humidity level? Once every two weeks?

I respectfully disagree with much of what already has been said.

Water meters are notoriously unreliable. They don't measure moisture levels but rather, soil conductivity, which can be affected by several factors, of which moisture level is only one. Other factors include soil composition, the presence of minerals, pH levels. More reliable is to poke your finger deep into the soil to test moisture or use a soil probe which takes soil samples and provides aeration at the same time.

Contrary to conventional wisdom, placing gravel in the bottom of the pot can compound the problem. The physics is a bit complicated but the gravel or pebbles can cause the lower soil to remain moist too long, placing plants as risk for root rot. Always pot plants in pots with drainage holes.

Watering by the calendar is never a good idea as factors such as amount of available light, pot size, humidity levels, even the health of the plant can all affect how long it takes soil to dry and different plant species have unique water requirements. If you think the decorative moss is retaining too much moisture, you might want to experiment by removing it to see if it makes a difference.

OK great, now I am really confused. Thanks to all anyway. I have repotted all my plants with stones for drainage, all pots are clay based, I have used high quality soil with peat moss and perlite, and I am going to say prayers. HA

I am begining to doubt the moisture meter also. I stuck it in a new bag of soil that was probably sitting in home depot for 3 month and it read 10 on the moisture level. Highest level. What?????

JimmyGreen, Often, I have gotten bags of soil from HomeDepot, Lowes, and a local nursery and they ARE wet if it's been raining in the area within the past two weeks. More often than not, these bags are stored outside. I have even gotten bagged mulch that was mouldy in the center of the bag.

Does this "10" soil you just tested hold together when you squeeze it in your hand? Spread some of it out to dry, pack it in a cup and try your meter again.

Please don't write off a moisture meter. It is merely a guide in addition to other efforts we all make in determining when to water.

Tending potted plants is trial and error. If at first we don't succeed, we try something different until we do succeed

Now THAT'S interesting!

Please explain it to me. While it may be complicated, I'd like to know more about this & I have time to listen... or, can you put up a link to information that you may have come across?

Thanks.

Initially it seems counterintuitive that adding pebbles could impair drainage but the science supports it. Principles of gravity, cohesion, and adhesion all interplay in the drainage of water in potted plants. A simple but good explanation can be found in this forum's archives https://www.agardenersforum.com/old/ubbthreads.php/ubb/nolongerexists?ubb=get_topic;f=27;t=001130;p=0

Sorry for the typed out URLs but the UBB code doesn't seem to be working, at least on my computer.

Happy reading!

It seems the forum administration has blocked the URL of that site but searching the keywords gravity, water adhesion, cohesion, perched water table, potted plants will net lots of interesting reading.

Thanks, Star! I'd never given any thought to the principles you mentioned (or to surface tension) in relationship to "drainage rocks" in a plant pot. VERY interesting... I'll have to mull it over for a while, so it can sink in!

I've never had a problem with plants such as my Dracaena, Spiders & Lipstick, & I do have rocks in their planters. I'd never seen it before... (entertaining, too)!

**By the way, Jimmy said that he replanted in clay pots. Uhhh, I don't think that was a good thing.. what do you think, Star? (Sorry Jimmy... I know it was a lot of work, but you might have to do the whole thing over!)**

You're welcome, Patty!

Like you, I've also had some success using drainage rocks in the bottom of pots, however, don't recommend it because it is more difficult to accurately monitor moisture levels deep down and, well, why take the chance, especially for someone already prone to overwatering or having plant problems?

Soil in unglazed clay pots dries out a little quicker than in glazed clay or plastic pots, which shouldn't be a problem if moisture levels are carefully monitored. I think more important is to use correctly sized pots. Most of my plants are in clay pots, others remain in their original ugly plastic grow pots, double potted in decorative pots (kinda defeats the purpose to have gorgeous plants displayed in ugly pots, right? At least that's how I justify my purchases to DH!)

Walking on lava rock?! OUCH!!! Sand is much easier on tender tootsies and very Zen. Bet it looks fantastic!

BTW, is there a trick to inserting those cute graemlins? Nothing happens when I click on them and I only know the code for a smilie.

Star

OK guys and gals, I will go over the entire set up since it seems you all may be picturing something different based on my lack of providing full info. For one I didn't mention the drainage holes and that may have led to confusion.

I have 6 pots and all of them are what I would call clay-based. I don't know too much about pots. Is there anything other than clay and plastic? These are what you would typically find at home depot. Polished on the outside but rough on the inside. They all have 3 to 4 drainage holes on the bottom. They all sit on top of a saucer. I have now placed a level of rocks in the bottom.

Now based on what Star said about the science behind the gravel, which sounds highly probable, I still don't think that would cause a problem because I do have the drainage holes. My soil is not going to be affected by being packed into the drainage holes because of the barrier of rocks and the rocks are not going to let the water sit because there is drainage. I see that this should be the best possible way to water and get the water to flow through.

I have not given up on the water meter although I will also test with the finger. The soil I bought was at home depot and it was in the area of the tropical plants. It was not outside where it could get rained on and it was on one of their typical pallet set ups where it probably had been sitting for a while. It is the greenhouse area which I am sure is a little more humid than the rest of the building but certainly should not have had water hitting it. It must be that the conductivity and minerals in it make the reading high. It is pre-fertilized mix. When you take it out of the bag it is black and a little moist. You can't make a mud ball with it but it isn't exactly dry powder either.

Jimmy, you sound like you're well on your way to success with your plants, because once a person gets a grip on all the interesting things like the ones we've covered in this thread, they have a lot better chance of being able to monitor the plants & watch for symptoms. (Lots to keep track of, huh?!)

Star dancer, if it isn't too much trouble I would like to inquire you on the soil probe you talked about. I am becoming more unsure of the moisture meter. This is what I typically see. The soil looks only slightly moist at best. Even a little dry and light brown on top and as I put my finger down an inch or two I find it to be slighty moist at best but it still does not stick together like a mudball. The moisture meter reads moist at two inches and then wet the farther I go down. I believe now that this is because of mineral composition and not the actual water level. How does the soil probe work and are they available at most places like Home Depot?

Jimmy,

My soil probe is made of durable, sturdy, yet inexpensive, plastic, 12" long plus handle, with 5 evenly spaced notches along the length of the probe to gather soil samples.

You insert the probe deep into the soil all the way to the bottom of the pot, twist the probe 1/4 turn, then pull out. Small soil samples are scooped up into the notches so you can more easily and accurately tell how dry or moist the soil is at different levels of the pot. I usually repeat the process 3-6 times to aerate the soil. If a plant is potted in a poper size pot, you will likely strike a root or two inserting the probe. Though unnerving the first few times it happens, don't worry, it won't harm the plant.

Pinch the soil in each notch between your fingers; dry soil will crumble into a fine powder and will easily blow away with gently blowing. The other extreme are the mud pies you refer to. Slightly damp and moderatly moist soils will fall in on somewhere on the continuum,, sticking to itself to varying degrees.

Soil probe results are another tool in an indoor gardener's arsenal to help accurately determine one of the most challenging aspects of houseplant care, after appropriate lighting. The finger method works well with smaller pots but is impractical with pots too large to deeply insert a finger.

Because I purchased my soil probe online, I've never looked for one in Home Depot or other retailers. In case it is against forum policy to post links to commercial sites, I'll PM you with information about mine.

BTW, it seems there is still some confusion about pots and drainage layers. I will return to this post, time permitting, to address why it is that even with drainage holes, potted plants are still at greater risk for root rot in a pot that has a bottom drainage layer. Unfortunaely, I'm half asleep and probably wouldn't make any sense if I tried to explain it now. Class starts early, so I'm off to bed!

Star