What is FULL SUN anyway?

[Kim]

kahili - I think we mostly agree, especially your post #30. It sounds like you are looking at it from the commercial grower's point of view, growing thousands of plants for wholesale or retail sale. I'm looking at it from the point of view of the consumer, who may have a handful of plants to place in the garden. My remark about the nursery trade was about labeling for retail sales to consumers who may not be experienced gardeners. The labels on plants in the larger nurseries in California almost uniformly describe full sun as 6 or more hours of sun with no further comment. However, when the nurseries are growing massive numbers of plants for sale, they are probably much more stringent about the needs of the "crops".

For palms, I don't think there is any variable about what constitutes full sun. Whether a particular palm can take full sun in Hawaii or La Habra may vary and can be worth discussing. But full sun is still full sun in either location; I'm with kahili on that point.

Okay, I'm boring myself, enough about that.

[Dypsisdean]

So, if I have explained to someone that Palm X is doing very well for me with 4 hours of full morning sun, have I used the term incorrectly? Do I need to say 4 hours of year round, unobstructed, cloud free, morning sun instead?

[Hammer]

  On 11/3/2012 at 5:10 PM, Kim said:

  On 11/3/2012 at 9:59 AM, kahili said:

This isn't that complicated...think of the day comprising morning sun,usually from when the sun starts to hit the area anywhere from 8-9 am to between 12-1 in the afternoon, and afternoon sun which would be between 12 and 1 pm to around 6 or so. Full sun would be the morning and afternoon exposures combined. Obviously full sun is anywhere where there are no trees or buildings to shade the area. Of course there can be some variations as to when the sun hits the area and when it stops hitting the area (such as 10 am to 5-6 pm) but full sun has to include the majority of the afternoon sun (at least to 4-5pm) . Afternoon sun is way stronger than am sun. If I needed full sun for a plant to do well, and had to choose between am and afternoon sun, I would always choose afternoon sun.

Where you are is irrelevant to this discussion, because the above definitions always apply. Afternoon sun is always stronger no matter where you are, and the hottest part of the day is between 2-4 pm.

The distinction you are making about morning sun vs. afternoon sun is a question of heat, not sun exposure. Plants that need full sun can get it from 7 am to 1 pm. If a plant requires heat, then of course the gardener will look for the warmest location, with hot afternoon sun. But 6 hours of sun, whether morning, afternoon, or a bit of each, constitutes "full sun". This is an accepted measure in the nursery trade, and is based on plants' requirements to flower, whether palms or petunias. By practical necessity, it is a generalization used for labeling plants to be sold to the general public.

When we discuss sun/shade requirements on an international palm-specific forum, the generalization is inadequate, and the specialists share their own refined and more specific terms, but that does not change the basic definition of "full sun".

Honest question...at what point does the "full sun" clock start during a day? Does 7am sun really equate to 1pm sun? Regardless of heat. The angle of the rays and the additional atmospheric "thickness" due to angle should impact this should it not?

[Hammer]

Nevermind...I see my question was already addressed. Sorry for the repeat.

[kahili]

Well that was fun!! Seriously though-I am glad that we are in agreement Kim! It is a good discussion to have when it comes to gardening. Sun is everything if you are growing sun loving plants. I go to friends houses where they have a lot of trees, only a few hours of sun and they are so severely limited in what they can grow. Breaks my heart lol

Good post Wal-I guess its safe to say that I never made it to the last sentence of Dave's post!

Dean-if you say morning sun-that says it all. I consult with landscapers on a regular basis on what flowers to plant on commercial properties and the first question I always ask is whats the sun situation? Full sun, am sun or afternoon sun? Second question is-is there irrigation. Toughest beds to plant-full sun, no irrigation and in a parking lot. At least none of us have that problem!

[mike in kurtistown]

I can't carry on any argument with botanical or nursery professionals on this topic, but I have observed that containerized palms that are shade lovers or have been kept in shade and have not been acclimatized to direct sun can be damaged by even an hour or two of exposure to direct sun at any time of the day. The effects might take several days to become manifest.

[Phoenikakias]

'Ful sun' is a planting place, where one can never shoot perfect pics during day light, except in the hours when sun is high in the sky

Edited November 4, 2012 by Phoenikakias

[doranakandawatta]

As Made Wijaya explained in his books, north and south façades are getting more sun in the tropics and close to equator;

In Sri Lanka I lost the north! Because you can be sun burned staying again the north façade.

And most houses and bigger buildings like Hotels are facing North, so east is not on your left, west on your right like in Europe

(See Kandalama of Geoffrey Bawa!)

Sorry if I am confused, but I am french.

[Walter John]

  On 11/4/2012 at 8:34 PM, doranakandawatta said:

As Made Wijaya explained in his books, north and south façades are getting more sun in the tropics and close to equator;

In Sri Lanka I lost the north! Because you can be sun burned staying again the north façade.

And most houses and bigger buildings like Hotels are facing North, so east is not on your left, west on your right like in Europe

(See Kandalama of Geoffrey Bawa!)

Sorry if I am confused, but I am french.

I'm confused, I thought you were Sri Lankan...

[doranakandawatta]

Sorry Wal

I am french living in Switzerland (landscape designer) and traveling to Sri Lanka every 4 months for holiday, I should have made roots there since I love this country and people.

Holidays in Sri Lanka means gardening, elephants, garden visits, visiting friends ...

My english is what a french can do!

[bgl]

Philippe,

Your English is great! And don't worry about Wal. He is just trying to make life difficult for you. Let's call it the "friendly atmosphere of PalmTalk"!

Bo-Göran

[smithgn]

I remember reading this thread from a while back and since then, I've gone back and re-read it without an answer to a current question I have.... I apologize if I may be threadjacking a bit... I also apologize in advance for the length of detail I may go into. Here goes:

As we all know, especially for some of us above the tropic of cancer (or below the tropic of Capricorn), the sun can be almost directly overhead in the summer time, but in the waning hours of the winter time, the sun makes brief, low rising passes above the horizon. This poses an interesting dilemma to some areas near houses or fences as far as sunlight goes. As for me, there's an area next to my house that receives 4+ hours of direct sun in the warm months, full sun in my opinion or close to it, but in the cold months, it is completely shaded. The sun doesn't get high enough over the horizon to send direct sunlight over my house and onto the area where I have my palms. So my question is... Would this area be considered a full sun area despite not receiving any sunlight in the winter time? On top of that, any sun loving palm would bask in the summertime sunlight in this area, but how would they do in the winter time with no direct sunlight? Or does it even matter since any of these sun loving palms would go into conservation mode any way during the winter months?

This is something I've always wondered... Glad I can finally get it off my chest and ask the experts.

Edited June 18, 2015 by smithgn

[_Keith]

By textbook, used by universities and landscaping licensing boards, you will be taught this:

• Full Sun: Fun sun means 6 full hours of direct sunlight. Those six hours could be from 8 – 3 or 12 – 6; anytime during the day. These hours can also be three morning hours, plus three afternoon hours.
• Partial Sun / Partial Shade: These two terms are often interchangeable to mean 3-6 hours of sunlight each day. While the terms are interchangeable, there is a default understanding. Partial shade typically refers to morning and early afternoon sun, while a plant listed as partial sun, relief from the intense late afternoon sun is needed. This shade could be from a structure or the shade from an old oak tree.
• Full Shade: Full shade means less than 3 hours of direct sunlight each day, best if it’s morning light. But even in the absence of direct sunlight, full shade can be a bright light. Plus, full shade likes a filtered sunlight the remainder of the day. Every plant needs some sun; even those that thrive in full shade.

These are the accepted definitions by those folks who define definitions, lol. To pass my Licensed Horticulturist test, I was expect to know those definitions.

However, we are each free to make our own definitions based on our local conditions and local nurseries frequently do. There livelihood depends on plants doing well in their market so they can be much more specific plant by plant.

I was also expected to know this information. But again, text book learning is one thing, experience is another. Find a trust worthy local nurseryman and trust them, with a guarantee of course.

[Ben in Norcal]

  On 6/19/2015 at 1:22 AM, _Keith said:

• Full Shade: Full shade means less than 3 hours of direct sunlight each day, best if it’s morning light. But even in the absence of direct sunlight, full shade can be a bright light. Plus, full shade likes a filtered sunlight the remainder of the day. Every plant needs some sun; even those that thrive in full shade.

I find this interesting. I'm not arguing with the definition, I just would have never personally thought "full shade" includes any hours of direct sunlight. Any direct sun whatsoever would, in my mind, mean not "full" but rather "partial" shade.

[_Keith]

  On 6/19/2015 at 1:33 AM, Ben in Norcal said:

  On 6/19/2015 at 1:22 AM, _Keith said:

• Full Shade: Full shade means less than 3 hours of direct sunlight each day, best if it’s morning light. But even in the absence of direct sunlight, full shade can be a bright light. Plus, full shade likes a filtered sunlight the remainder of the day. Every plant needs some sun; even those that thrive in full shade.

I find this interesting. I'm not arguing with the definition, I just would have never personally thought "full shade" includes any hours of direct sunlight. Any direct sun whatsoever would, in my mind, mean not "full" but rather "partial" shade.

Not disagreeing with you, but many times in full shade in early morning and late evening, whenthe sun is low on the horizon, some sunlight can peek in. There can be a profound difference between the last 3 hours of sunlight in winter and in summer, too. For the first 3 hours of sunlight, not so much. It is kind of like zones, a general guide. These things are defined so that they can give test with right or wrong answers. Plants have a different attitude towards life as the only test they pass is survive, thrive, or not.

[smithgn]

I've copied and saved what you posted to my computer. Thanks Keith, very useful information. I've heard that full shade is equal to or less than 3 hours of sunlight... A bit odd as I would also think it should be called partial shade instead of full shade. But what about the varying degrees of sunlight from season to season like in the example I mentioned above? Would these designations only be made by the amount of sunlight received in the summer time or does it also include the winter time as well?

[DoomsDave]

Full Sun, like common sense appears to have a more variable component than generally realized.

I don't think full sun in Phoenix is the same as it is in La Habra, or Hilo.

This is important, because admonitions to plant in full sun should be qualified.

[DoomsDave]

  On 11/3/2012 at 9:59 AM, kahili said:

This isn't that complicated...think of the day comprising morning sun,usually from when the sun starts to hit the area anywhere from 8-9 am to between 12-1 in the afternoon, and afternoon sun which would be between 12 and 1 pm to around 6 or so. Full sun would be the morning and afternoon exposures combined. Obviously full sun is anywhere where there are no trees or buildings to shade the area. Of course there can be some variations as to when the sun hits the area and when it stops hitting the area (such as 10 am to 5-6 pm) but full sun has to include the majority of the afternoon sun (at least to 4-5pm) . Afternoon sun is way stronger than am sun. If I needed full sun for a plant to do well, and had to choose between am and afternoon sun, I would always choose afternoon sun.

Where you are is irrelevant to this discussion, because the above definitions always apply. Afternoon sun is always stronger no matter where you are, and the hottest part of the day is between 2-4 pm.

Hmm.

Maybe the "definition" of full sun might be universal (as you note), but whether that full sun is safe for a given palm is highly location specific. Rhopalystyus sapida thrive in full sun in Costa Mesa, but fry and die in Riverside.

This is a crucial issue if you're editing a book on palm culture, which will include recommendations as to "full" "part" "filtered" etc., sun exposure.

[_Keith]

  On 6/19/2015 at 5:40 PM, DoomsDave said:

  On 11/3/2012 at 9:59 AM, kahili said:

This isn't that complicated...think of the day comprising morning sun,usually from when the sun starts to hit the area anywhere from 8-9 am to between 12-1 in the afternoon, and afternoon sun which would be between 12 and 1 pm to around 6 or so. Full sun would be the morning and afternoon exposures combined. Obviously full sun is anywhere where there are no trees or buildings to shade the area. Of course there can be some variations as to when the sun hits the area and when it stops hitting the area (such as 10 am to 5-6 pm) but full sun has to include the majority of the afternoon sun (at least to 4-5pm) . Afternoon sun is way stronger than am sun. If I needed full sun for a plant to do well, and had to choose between am and afternoon sun, I would always choose afternoon sun.

Where you are is irrelevant to this discussion, because the above definitions always apply. Afternoon sun is always stronger no matter where you are, and the hottest part of the day is between 2-4 pm.

Hmm.

Maybe the "definition" of full sun might be universal (as you note), but whether that full sun is safe for a given palm is highly location specific. Rhopalystyus sapida thrive in full sun in Costa Mesa, but fry and die in Riverside.

This is a crucial issue if you're editing a book on palm culture, which will include recommendations as to "full" "part" "filtered" etc., sun exposure.

As I said, the goal here in my opinion is to create standardized definitions on which one can be tested, and the answer clear. Also, I think the given here is that they are assuming you are planting a known plant for your area with an appropriate tag on it stating growing conditions. You know, the everyday stuff at the local garden center and the "Proven Winners" for each state. With rare or new or unique or unknown plants for a given area, these things may not be so defined or even known. We should all know that there are no absolutes in gardening anyway.