"Indicator" plants for knowing when to water your palms

[Justin]

This is always a tough time of year in SoCal to know when to water. We get hot, dry winds during the day, but it really cools off at night, and occasionally we'll get (for us) big rainstorms. I'm tempted to just go without any supplemental watering for long spells, but with palms its difficult to tell when they're starting to get thirsty. The thought crossed my mind that I could plant one or two "indicator" plants - plants that would start to wilt when they get thirsty. This would let me know it is time to water everything. Of course, such an indicator plant would need to be something that would bounce back immediately after getting watered.

I was wondering if anyone used any indicator plants, and if so what plants they used.

Thanks in advance.

[MattyB]

DeanO taught me that impatients (the cheapo standard kinds) are a great plant for that.

[CromulentKevin]

Eucomis (i.e. pineapple lilly) seems to be a pretty good indicator, as it droops quite easily and perks up quickly once watered. Obviously this doesn't work too well in the winter months when they are dormant. . .so I haven't figured out anything good to indicate when I should water in the winter since nothing is really doing anything. For example it rained pretty heavy this past weekend and rain is forecast for next weekend, so I'm tempted not to water all week, but I might turn on the system once just cause daytime temps are still kinda warm.

[richnorm]

Coffee plants are good as are ligularias (sp?). I have also tried Achontophoenix in areas which I may plant later but don't want to ever have to water. Indicator plants are good to test general growing conditions eg tamarillos grow really fast but need good drainage and light so you can observe them for one year and get an idea of how all the factors add up. They also provide good temporary canopy but are heavy feeders. Watch the impatiens or you will be over-run by them!

cheers

Richard

[MattyB]

I think that getting to know you soil is a key factor here. Anytime you dig around, if you take note of the garden location, the last time you watered or when it rained, what the temps were like during that duration, and the mulch thickness or lack thereof, then you can get a feel for how your soil performs and what it's watering needs are going to be for plants that like it wet, moist, dry, etc. Don't underestimate the power of mulch and proper deep watering. For average soils, even plants that are "water lovers" once in the ground for a year, properly deep watered and heavily mulched, will possibly not require water more than 2 times a week even in the hottest time of the year. I'm a firm believer that overwatering is a major problem for many gardens. Also regarding drip irrigation; I've found that providing drip irrigation to the roots of a plant that is surrounded by unirrigated ground around it is a very good condition. A deep watering can be provided at infrequent intervals forcing a deeper, more drought tolerant root system at the same time that the dry earth around it is wicking away any excess moisture providing a form of lateral drainage, even in clay soils. Plants love the oxygen of soils that aren't constantly wet. Just some stuff I've discovered. Hope some of it helps.

[DoomsDave]

Hmm.

That is a fascinating, clever idea, particularly to avoid the mindless, water-wasting "clockwork orgy" of watering that most people with timers use. There's a tendency to "set and forget" which leads to overuse. At least in theory. In my case, I water once a week, unless it rains or it's cool, in which case less often. So, I'm Clockwork Orgy Lite.

But . . . .

I can see problems, too. There are many variables in individual gardens, particularly relating to wind exposure and soil conditions.

Impatients wilt at the slightest provocation, which is exactly their problem, particularly if your palms are better at resisting drier conditions. Impatiens will be good, IMHO, for situations dealing with jungle understory palms that just can't take the dry at all. They'd be less useful in dealing with, say, Queens that take drought much better.

That said, I'll continue to watch this post with interest.

[MattyB]

That's true Dave, Impatiens, will be a good indicator for the area of the garden that needs to stay constantly moist. But why would you need an indicator for the other areas with plants that don't mind drying out. Let 'em dry out regularly and water them regularly and they'll do fine.

[LJG]

Justin, don't you have DG over there? I do here in Vista and even through winter, I water twice a week (down from 3 in summer). That is the beauty of DG! I even have Crotons that hate wet, cold soil here in socal. I have no issues with them in winter.

[NakaB]

Check out Farfugium japonicum 'Gigantea'. Synonym:Ligularia tussilaginea. Beautiful plant with thick glossy leaves and fairly easy to find in San Diego. I water when the leaves start to hit the ground. Usually twice a week. The leaves are back up by the following morning.

[doubravsky]

wow... that Farfugium is pretty! Just looked it up. Will it handle Riverside summers?

I find this topic interesting. I probably water too much... as i'm always worried about stuff drying out. I do have drip, so I figure even if I'm watering 30 minutes per day during the hear of the summer, the DG will let it drain quick enough.

Matty, how long would you water on a drip system to ensure deep watering?

[DoomsDave]

Hmm.

THose Farfugii - whatsis are cool, but they get a bit big for some applications . . . . .

[Creekside]

I watch the resurrection ferns (Polypodium polypodioides) on the oaks for this very purpose. When they're green and "resurrected" I don't need to water. Of course, most of the time they're brown and crispy-looking, but when they're not, I know that everything else is happy, too. That being said, they don't grow in Cali (naturally, at least.)

[Justin]

Hmm, I water once a week only as it is. I was hoping to get it down to less, but since my watering is already fairly infrequent, I don't want to take it too far.

I do like the plant ideas so far, and am curious to see what else gets mentioned.

[osideterry]

We are likely in an El Nino, and rain is forecast for December 7-10. In years like this, I just leave the irrigation off until we go 3 weeks without rain. In 2005 that was several months without touching the clock.

My soil isn't quite DG, but I have mound planted several palms. I water about once a week starting in December, if there is no rain. I'm convinced one of the reasons I saw so much damage in January 07 was that I was under-watering.

[Bennz]

I've found Archontophoenix in particular surprisingly drought tolerant. Weed grass growing in the same pots as them dies from drought before they start to suffer.

As for true indicator plants, there is a major difference between plants that indicate conditions dry enough to limit growth, and conditions dry enough to cause damage.

[MattyB]

Matty, how long would you water on a drip system to ensure deep watering?

Dave,

I have rock anywhere from 12" to 24" below. I'm assuming that dicots can penetrate it and palms cannot.

For dicots I water with 1 GPH drippers (spread out around the crown of the tree, usually 4) for 4 or 5 hours, once a week in hot summer, less as we get colder. Note: Bismarckia, D. onilahensis, Copernicia are also on this schedule because they can tolerate possible drying out but I really don't think it's getting dry down there.

For palms I water with 2 GPH drippers (usually 2 for each palm) for 1 to 2 hours, twice a week in hot summer, less as we get colder.

[epicure3]

I think it really depends onthe type of palms you want to keep an eye on. More tropical palms don;t want to be over watered in the winter whilst more hardy ones do. I don't think that impatiens are a good way to know if your palms need water. Impatiens need a lot more water than most palms in socal need (in winter). I think that crotons are a good indicator plant. They don't like much water in the winter, but they still need it. I had some start to wilt (get droopy) last March (I think it was March) after not watering for some time. After giving them some water, they came back. Crotons are fairly drought tolerant for such a tropical plant, so I knew it was time to water.

[doubravsky]

Matt... thanks. I use 2 gph drippers too... 1 - 3 emitters depending on size and type of palm. when it gets up over 100f I go to 30 minutes/day, which would be 3.5 hours/ week... about the same total amount of water. Maybe I'll try backing the days off and upping the time per watering to encourage deeper root growth.

[MattyB]

I think that's a good strategy especially if you have deeper soil than me, which most people do. And you can always go out and spray down the leaves and trunk bases real quick with relatively little water on those super hot days to add some moisture to the mulch. But even if it gets to above 100F there's no way your soil will dry out if it's saturated down 2 feet deep and mulched. Imaging if it's saturated down to 2-4 feet with ample roots occupying that deep zone. Your plants will be very resistant to hot dry periods and your watering schedule won't need to be adjusted. I can recall several times I've put a sprinkler out on low and ran it for half an hour thinking that I was deep watering, only to find that the water was actually just spreading out on the surface below the mulch and digging down revealed that I had watered only a couple of inches deep and used a lot of water to do so. The drippers apply water so slowly that it has no choice but to go down.

[Jerry@TreeZoo]

Justin,

Good Thread!

I use a particular Croton that probably gets too much sun. It is on the north side of my yard while on the south side I watch both a Cocoloba pubescens and a Stemadenia litoralis. When they wilt it is pretty dry but they are the first ones to show stress. They also respond well to water and recover quickly.

[epicure3]

Justin,

Good Thread!

I use a particular Croton that probably gets too much sun. It is on the north side of my yard while on the south side I watch both a Cocoloba pubescens and a Stemadenia litoralis. When they wilt it is pretty dry but they are the first ones to show stress. They also respond well to water and recover quickly.

Stemmadenia is another good one but it is more of a tree. I have one about to go into its first winter. It's about 5' high with an equal spread. Very nice tree.

[daxin]

I guess most plants will give you indications when they get really thirsty, but some are more obvious than others. For very sensitive ones, most of the tropical herbaceous perennials will work very well. Personally I like Iresine and Crossandra. For moderate sensitivity, broad-leaf tropical shrubs are pretty good. Examples are Tabernaemontana divaricata and Murraya paniculata. For good drought tolerance, Aeoniums and Echeverias will shrivel and tighten up their rosettes if not getting enough water, but they do have dormant seasons (Aeonium in summer and Echeveria in winter) so you may need both for all year indication.

One other thing to watch for is temporary wilting, which could happen in summer or when the Santa Ana winds are blowing. The leaves lose more water than the roots could supply and thus they start wilting. However, if the soil is already saturated, more water would not only be wasteful but also might suffocate the root system. In this kind of situation, the indicator plants might also give you false alarms. If you suspect that the soil is pretty wet, you can wait overnight and see if the plants can recover. A more accurate way to check is a soil moisture probe (~$5 from Home Depot or Lowes) and spraying anti-transpirants such as Cloud Cover will help the plants stay hydrated.

In general, much more plants die from over-watering than from under-watering, so it is usually better to err on the under side and adjust up. I am not sure if there are similar palms, but certain fussy garden plants such as Boronia megastigma require well-drained acidic soil with constant moisture. For these it is almost impossible to get the watering right and thus they are treated more like annuals since they often only last one or two years in gardens.

[Dypsisdean]

DeanO taught me that impatients (the cheapo standard kinds) are a great plant for that.

So you do pay attention - sometimes.

[MattyB]

DeanO, I take the role of the unassuming genius. And a humble one to boot.

By the way (sorry to keep straying off topic) I just remembered that I punch a deep hole, with a pointed digging bar, next to all of my drippers and pour granular fertilizer down there and cover with mulch so it dosen't fill back up with dirt. Basically, the poor man's version of a fertilizer spike. But with a 18" deep hole punched in the dirt this changes the saturation pattern to a very cilindrical one at the surface. So the water is going straight down pretty far before hitting undisturbed soil and spreading out. This watering technique is similar to those fancy dancy subsurface tree watering tubes that have an emitter far below the surface. Just thought I'd finish my dripping thoughts to be thorough.

[Dypsisdean]

I wish I could attribute your genius to my side of the family.

[Kris]

For me the crotons & verigated hibiscus works as indicators,when i forget to water our garden,these plants leaves all drop and looks quite shabby.So naturally we have to water the garden soil area !

love,

kris

[tropicalb]

i sometimes allow the growth of certain types of plants in some of my containers that tell me precisely when i need to water.....very inexpensive and accurate method.

they're called "weeds".

[Jasen]

Florida wild coffee (Psychotria nervosa) is a great indicator plant for those in usda zone 9-11. While it is tolerant of drought, it does tend to wilt a bit during prolonged dry spells. The wilting is a benign reminder that I need to get the watering hose out. Honorable mention goes to rouge plant (Rivina humilis).

[BS Man about Palms]

i sometimes allow the growth of certain types of plants in some of my containers that tell me precisely when i need to water.....very inexpensive and accurate method.

they're called "weeds".

Burt-

Didn't you learn that secret when you came by my greenhouse?

Anyway, I stumbled on an "expensive" indicator plant a month or more ago. I have 2 Cycas daeboensis with about 4" caudex or so and both with 2 long leaves. During the "house final push" I did not water the Cycad area much. When I went over there, I saw the one with the two "taller" leaves at almost a horizontal plane. I checked the soil and sure enough, very dry. I watered it and the rest around quite well and over the next 2 days, the two leaves came back up to about a 75 degree angle, basically where they were.

I don't think I want to do that on a regular basis.

[_Keith]

OK, it would seem that there would be no single indicator plant. The indicator plant would need to have roots that penetrate at the approximate depth of the palm being monitored to be relevant. I mean if a palm has roots 2 to 3 feet deep, then an indicator plant with roots in the top 6 inches of the soil, it would not really be an indicater of water stress on the palm.

[DoomsDave]

WAIT!

The [expletive] WEEDS in the pots, wilt beforethe palm does, oh, scream, hee hee hee

[Moose]

Florida wild coffee (Psychotria nervosa) is a great indicator plant for those in usda zone 9-11. While it is tolerant of drought, it does tend to wilt a bit during prolonged dry spells. The wilting is a benign reminder that I need to get the watering hose out. Honorable mention goes to rouge plant (Rivina humilis).

Or crotons ...

[_Keith]

Thanks Moose. This might be a nice thread to get some fresh input on. Although not common in other areas, I know if my established Azaleas start to show indications of dryness everything else will be suffering soon thereafter.

[KennyRE317]

Since I have a container ranch its been easy to check if its time for water, u sually once a week but twice during heatwaves. Once winter rolls around i will probably water every other week and only in the morning if there's no rain.

[fan palm]

_{i use a couple of black bat plants (tacca chantrieri) in my shadehouse - first things to wilt everytime!}