How Much Annual Rainfall Do Your Palms Really Get?

[_Keith]

No, not the numbers from the National Weather Service, or even from your own weather station, I mean the real amount your palm can utilize.

After a nice little short drought of a month or two, I watched a couple inches of rain fall yesterday and get soaked right in. I watched another 2 inches fall today or which I am guessing a half or more was run-off. And as it goes in Louisiana, we will likely get several more inches in the next couple of days or which mostly all will be run-off. So, of let’s say 6 inches of rain, the actual rainfall that benefits my garden will be around in the 3 inch range, the rest of which runs down the streams and on to the Gulf of Mexico.

This is why in an area with 60 inches of rain fall a year, we still have spring and fall droughts and have to drag out water hoses for the unestablished plants. Looks like somebody like Axel’s situation is even more pronounced. I have never seen an attempt to quantify the useable rain an area gets as opposed to run-off.

So, when calculating rainfall needs for your palms, just something to think about.

[Mauna Kea Cloudforest]

I get 60 inches as well, but it's even worse than you in terms of run off because my garden is on a hillside. This is why my ground water recharging system is so critical. Runoff is captured in tanks and re-distributed while it's raining through the irrigation system and via leach lines.

[trioderob]

about 3" inches a year

praying for El Nino

[Kostas]

My garden is on the great plains of Helia and the whole lower part of my property is totally flat,while all planting beds are edged with a decorative, 2 brick high frame,so I have no run off from the 1m of rain my area gets. Plus my very shallow water table provides for the plants's water needs way longer than plain rain would

[_Keith]

My garden is on the great plains of Helia and the whole lower part of my property is totally flat,while all planting beds are edged with a decorative, 2 brick high frame,so I have no run off from the 1m of rain my area gets. Plus my very shallow water table provides for the plants's water needs way longer than plain rain would

Yep, I have a shallow water table as well, hence my comment about water hoses until established. It is rare to have to water anything after the first year unless it is super sensitive.

[DoomsDave]

Good question.

The times I've watched, I've had little run off. Most of my garden is on relatively flat land, and the slopes are left rough to let the water soak in. (I overhead water.)

But, when it rains hard and the soil gets really soaked, there is run off, though percentage wise I couldn't say.

[Jerry@TreeZoo]

I would say that in my yard I have absolutely no runoff. Even when we get a real toad strangler, it all stays in my yard. What hits my driveway runs almost to the street but is caught in a swale, still in my yard.

The problem is that in dry times, the water has percolated too deeply, or evaporated out of the soil so that it cannot be accessed by my plants. My elevation is 15' more or less and canals in the neighborhood are at about 7'. Too deep for roots.

[palmsOrl]

Here, as I would imagine with most areas in the Southeast US, we can have a ton of rain during the rainy season. Even if almost all of it is usable, after a few months of dryness, it has all either soaked into the water table or evaporated. As an aside, we were not drier than normal this spring (at times even wetter than normal), yet I felt like I had to do my fair share of watering to keep everything happy.

Another factor in my gardening space is canopy. Planted areas under a dense trees or other vegetation get significantly less precipitation getting into the soil than uncovered areas. I have an 70-80 ft Norfolk Island Pine in the yard and the circle directly under it gets maybe 1/4 of the amount of rain as elsewhere in the yard. I found this out with a couple of strategically placed rain gauges. I would imagine this effect to be most pronounced during a brief heavy rain and not quite as much a factor during many hours of torrential tropical rains. Basically my thought is, said space may only get 1/4 of the total rain from a brief 1" downpour, but would pick up a lot more than 1/4 of the rain from 5" of heavy rain falling over 8 hours.