Palm Growth Rates

[PalmGuyWC]

Like Wal, I'm conducting a little experiment of my own. After 5 days of blistering heat, the heat wave is subsiding and my low this morning was 60 F (15C), which is about normal for this time of the year. Last evening, I marked 3 different palms with a felt pin. Rather than just puting a line across the emerging frond and the nearest petiole, I drove a thin bamboo stake in the ground next to the palm and put the mark on the emerging frond at the top of the bamboo stake. I think this is a more accurate way to determine growth rate since a nearby petiole could be growing also.

I'm trying to determine if palms grow more at night than they do during the day. The 3 palms I marked were Trachycarpus wagnerianus, Parajubaea torallyi, and a Butia X Parajubaea. This morning after 12 hours, I measured the growth rates on the youngest emerging spear, and the Trach, had grown 1 inch, and the other two a little less than 1". This evening after 12 hours, I will measure again. I will repeat this process for several days and then average it out.

I have always heard that plants make food during the day, and then matabolize it at night. We shall see.

Dick

[Tyrone]

My palms always do there growing at night. I've done the mark spear thing for a few years and have found that right after sundown when the temp is still quite high is when they do there fastest growing, then as the night cools down into morning they just slow down, and stop once the sun comes up, metabolise throught the day with photosynthesis and repeat the process after sundown. During summer, I've also guaged how well a dose of fish and seaweed will effect growth during the night. My findings were that it makes an enormous difference to palms like my Hydriastele wendlandiana and my coconut, and I can't see why it won't work for all palms. Obviously gross feeders will show the most dramatic response to it.

regards

Tyrone

[PalmGuyWC]

We are just ending a 5 day heat wave, so I'm sure my palms are at max growth right now. They were well watered and fertilized before the heat wave and I don't dare give them any more fertilizer as I always tend to over do it. I am sure of what the results will be, but I wanted to do it just for the heck of it. Unfortunately, no way to check the growth rate on the larger palms. I see spears opening up all over my garden. I see I cooked a couple of newly planted Agaves.......to much to soon.

Dick

[epicure3]

Sort of off topic, but i notice the same with soil temperatures. I have a soil thermometer that never changes during the day. However, at night after a hot or cold day, the reading can change. When I check it in the morning, there can be an almost 1 degree shift from the previos day.

[PalmGuyWC]

It never occured to me to have a soil temp. probe. How far do you bury the probe? After 5 days of extream heat, I did notice the water from my hose was warm this morning and normally it's pretty chilly. In the winter time, I trap rain water, then bring it inside to warm to room temp. before I water my potted plants.

Dick

[bgl]

As far as I know, soil temp is critical, and really the determining factor in growth rates. In a place where you have a cool, or cold, winter the root system may go into something close to hibernation, preventing any substantial growth.

[Mark_NoVA]

Interesting--when you measured with the fish/seaweed, what time of day did you do the watering?

  Tyrone said:

My palms always do there growing at night. I've done the mark spear thing for a few years and have found that right after sundown when the temp is still quite high is when they do there fastest growing, then as the night cools down into morning they just slow down, and stop once the sun comes up, metabolise throught the day with photosynthesis and repeat the process after sundown. During summer, I've also guaged how well a dose of fish and seaweed will effect growth during the night. My findings were that it makes an enormous difference to palms like my Hydriastele wendlandiana and my coconut, and I can't see why it won't work for all palms. Obviously gross feeders will show the most dramatic response to it.

regards

Tyrone

[Nigel]

I really dont agree that soil temp stops top growth.

Here in the UK in spring new top growth tends to be yellow for a short period whilst the ground is cold ,what happens is that the palms grow chlorotic leaves because the soil is too cold to absorb the nutrients.

These leaves only green up when the soil warms up.

Night time temps are far more critical to growth, in my opinion its how low the temperature drops at night that is the limiting factor.

As to palms appearing to grow during the night, this is because the vascular system is occupied during the day providing water to leaves for transpiration, only at night are the building blocks translocated to the new cells formed during the day before.

[epicure3]

  PalmGuyWC said:

It never occured to me to have a soil temp. probe. How far do you bury the probe? After 5 days of extream heat, I did notice the water from my hose was warm this morning and normally it's pretty chilly. In the winter time, I trap rain water, then bring it inside to warm to room temp. before I water my potted plants.

Dick

My soil probe is about 1' down. Whether that is an appropriate depth, I couldn't tell you.

[epicure3]

  bgl said:

As far as I know, soil temp is critical, and really the determining factor in growth rates. In a place where you have a cool, or cold, winter the root system may go into something close to hibernation, preventing any substantial growth.

That makes sense. Obviously, it depends on the species of palm. My soil temperatures bottom out at about 57 for a couple of weeks in the dead of winter and go up to the mid 70s during the summer. Surprisingly, some species that I have continue to grow even at that low 57 degree mark, albeit slowly. Dypsis lutescens, hyophorbes, euterpe, veitchia all continue to grow during the coldest soil temps. Beccariophoenix, roystonea, coccothrinax, dypsis decaryi, and dictyosperma all appear to shut down. Fairly random.

[Tyrone]

  Mark_NoVA said:

Interesting--when you measured with the fish/seaweed, what time of day did you do the watering?

  Tyrone said:

My palms always do there growing at night. I've done the mark spear thing for a few years and have found that right after sundown when the temp is still quite high is when they do there fastest growing, then as the night cools down into morning they just slow down, and stop once the sun comes up, metabolise throught the day with photosynthesis and repeat the process after sundown. During summer, I've also guaged how well a dose of fish and seaweed will effect growth during the night. My findings were that it makes an enormous difference to palms like my Hydriastele wendlandiana and my coconut, and I can't see why it won't work for all palms. Obviously gross feeders will show the most dramatic response to it.

regards

Tyrone

I'd generally give them the seaweed fish mix around 5pm in the afternoon.

Best regards

Tyrone

[Mark_NoVA]

Very interesting! If this is how it works, is there also growth during the day on a day when there is not much transpiration, such as an overcast rainy day?

  Nigel said:

As to palms appearing to grow during the night, this is because the vascular system is occupied during the day providing water to leaves for transpiration, only at night are the building blocks translocated to the new cells formed during the day before.

[Nigel]

  Mark_NoVA said:

Very interesting! If this is how it works, is there also growth during the day on a day when there is not much transpiration, such as an overcast rainy day?

  Nigel said:

As to palms appearing to grow during the night, this is because the vascular system is occupied during the day providing water to leaves for transpiration, only at night are the building blocks translocated to the new cells formed during the day before.

Mark, I think not because the flow is still going to the leaves and the vascular system cannot be used for 2 purposes at once. However, it should be noted that applying ample water will speed growth simply because during shortages of water the plant reduces its water use by reducing its time of photosynthesising.

[PalmGuyWC]

The experiment continues.......Yesterday morning, exactly 12 hours after I had marked the emerging spears, I marked the spears again. The night before they had grown approx 1" in the 12 hr period. Last evening at 12 hrs., I marked them again. The Trachycarpus actually grew about 1/4" during the daylight hours, while the Parajubaea and the Butia X Parajubaea hybrid hardly grew at all. This morning, I marked them again, and recorded about 1" of growth during the night. This proves to me beyond a shadow of doubt that palms do most of their growth at night.

It only stands to reason that the Trach. wagnerianus is the fastest growing palm, as it grows at least 12 fronds in my climate during the growing season, while the other two are pinnate, with much larger fronds and only grow about 6 fronds a growing season. It seems all of your observations more or less agree, and I'm sure ground temperature, air temperature, the amount of moisture and nutrients, and day and night length all come into play with plant growth.

Dick