Monitoring soil moisture with a plant

[Javaman4373]

I am curious if people are using a sentinal plant to monitor soil moisture on potted trees. I am thinking of intentionally planting an indicator plant beside a bonsai tree that would droop or otherwise indicate when soil moisture was getting too low. What plants would make a good monitor of this type?

 

[ShadyStump]

I don't know of anyone doing it intentionally, but many people do leave the weeds in a pot and use their condition as one of many indicators of soil conditions.
To do it intentionally you'd have to know the needs of your sentinel plant relative to those of your tree, while remembering that it's taking up space and resources in the pot as well. Really there so many factors that would have to be taken into account that I don't feel it'd be accurate, or generally worthwhile.

Gardeners, and to an extent some farmers, do use sentinel plants in a was when growing in the ground, but this is generally just knowing the needs of the various things they have planted, and what deficiencies affect which of them first. They see something in one type of plant early on, and treat the whole plot to maintain a healthy balance.

 

[nuttiest]

I like to leave 'cute weeds' right in the pot, easy droopy test, but some decorated with oxalis got rust last year when the plant was fine.
Switching to cherry tomato seeds.

 

[Colt Carson]

Unfortunately, most of the weeds I've known were much tougher than a Bonsai Tree
Maybe a small, thirsty tropical plant would work.

 

[Javaman4373]

I read somewhere that a strawberry plant made a good sentinel for a larger potted plant. Supposedly it telegraphed that moisture levels were too low by drooping. That got me thinking if there were better options for such a planting on bonsai pots. A plant that is small, unobstrusive, sensitive to dryness, and shows low moisture clearly.

 

[ShadyStump]

Companion planting is common in container gardening, a little less so in vegetable gardening. There it's usually plants/flowers that have complimentary nutrition needs, or are pest repellent.

I've thought about it for penjing, but not looked into it seriously. I do know from research that curl leaf mountain mahogany is nitrogen fixing, so planted with another type of tree or two as a scene it might benefit the whole bunch. A similar strategy that seems more like you're thinking would be a group planting with a hardy but water hungry tree planted with water tolerant trees.
Otherwise you're just combining your accent plants in the same pot as your tree

 

[nuttiest]

strawberry sounds great, I am getting some seeds.

 

[rockm]

I would be EXTREMELY careful with this method. There is a huge margin of possible error, from inappropriate species, to soil types. Bonsai soil typically dries down from the surface and it dries much more quickly than potting soil (by design) A plant with shallow root systems in that soil will show stress long before the interior and bottom of the container where the tree's roots are, is dry, which can lead to over watering. Additionally, bonsai are typically placed in full sun, speeding the drying of the top of the soil.

Best way to learn how to water is the hard way. Learn what to look for in the soil and the weight of the pot.

 

[nuttiest]

I would be EXTREMELY careful with this method. There is a huge margin of possible error, from inappropriate species, to soil types. Bonsai soil typically dries down from the surface and it dries much more quickly than potting soil (by design) A plant with shallow root systems in that soil will show stress long before the interior and bottom of the container where the tree's roots are, is dry, which can lead to over watering. Additionally, bonsai are typically placed in full sun, speeding the drying of the top of the soil.

Best way to learn how to water is the hard way. Learn what to look for in the soil and the weight of the pot.

yep... if i check roots on the dry pumice ones the bottom is sopping wet where pumice is in contact with plastic. but this is due to using plastic. Only thing better than metered water on the plastics is maybe an absorbent clay tile at the bottom... and some veggies!

 

[Cadillactaste]

No need...this is the best method.

Watering Bonsai Trees

Watering Along with proper siting, proper watering is among the most critical tasks to master to become successful in the art of bonsai. Water too frequently, or too infrequently, and the tree's health declines. Usually, the symptoms of...

www.bonsainut.com

 

[bonsaiDerek]

stick a bamboo skewer, like from a shish kabob, in the soil, pull it out daily to see if its moist, if not, water

 

[Paradox]

When I was learning I used a wooden chopstick in the soil to monitor soil moisture

 

[bonsaiDerek]

very similar but i think skewer is more accurate

 

[Paradox]

very similar but i think skewer is more accurate

I was not using a skewer. They were chopsticks left from eating Chinese food.

They are both made of wood/bamboo. Acts exactly the same. The size/diameter makes no difference

 

[dbonsaiw]

strawberry sounds great, I am getting some seeds.

FWIW, strawberries are one of the most invasive things in my yard. I planted a few three years ago and the runners spread all over the place. Each plant had several runners each year and they multiplied exponentially. My 9 year old likes eating them off the plant, otherwise I'd rip em out.

 

[nuttiest]

In NY?! I can't do them any time I buy the crowns even. Now that I derailed here already I wonder what plants would do as a good ph pre- indicator, I could use help with azalea I kill them and then go back to nursery to see if they have the same stock, theirs are fine. I think the difference is well water.

 

[nuttiest]

And sorry Javvaman, what to you think of a ph indicator plant as well?

 

[Paradox]

And sorry Javvaman, what to you think of a ph indicator plant as well?

Generally in bonsai we dont want additional plants in the bonsai pot with our bonsai because they compete for nutrients and moisture
You arent going to be able to use "monitoring plants" to fix the problems you are having

If your azaleas are dying and you think its because of the pH of the water, you might look at the soil you have them in. Put them in soil that is slightly acidic (a common one is Kanuma) and try feeding them fertilizers good for acid loving plants which help to keep the pH on the acid side where they like it.

 

[Javaman4373]

And sorry Javvaman, what to you think of a ph indicator plant as well?

I would be interested in that subject as well. I don't think the concern about competition for water or nutrients by a single companion plant is significant since the person supplies both as needed and they are not rate limited. There would be at least a theoretical concern about a plant that might produce chemical inhibitors of other plants, similar to juglone produced by black walnut trees.

 

[nuttiest]

Generally in bonsai we dont want additional plants in the bonsai pot with our bonsai because they compete for nutrients and moisture
You arent going to be able to use "monitoring plants" to fix the problems you are having

If your azaleas are dying and you think its because of the pH of the water, you might look at the soil you have them in. Put them in soil that is slightly acidic (a common one is Kanuma) and try feeding them fertilizers good for acid loving plants which help to keep the pH on the acid side where they like it.

Well I meant same soil as purchased, I get it home, trim heavily, and dead in 2 months. I see other people taking up to 1/3 off azalea.