More Fertilizer Talk - Higher Nitrogen at First?

[_Keith]

"Fertilization with high-nitrogen fertilizer for the first 12 months, followed by 12 months of moderate nitrogen landscape palm maintenance fertilizer resulted in the best overall quality in both experiments."

http://ashs.org/pressrelease/index.php?option=com_content&view=article&id=1101:high-nitrogen-fertilizers-tested-on-post-transplant-ornamentals-&catid=2:horttechnolgy&Itemid=4

DAVIE, FL – The nutrition and fertilization needs of container-grown ornamental plants during production are well-documented, but there is limited research about the plants’ fertilizer requirements following transplantation into landscapes. A study from scientists at the University of Florida published in HortTechnology provides growers with new information and guidelines for post-transplant fertilization. Timothy K. Broschat and Kimberly Anne Moore reported on a study designed to determine if increasing the nitrogen content of fertilizers applied to transplanted container-grown areca palm and chinese hibiscus plants could accelerate the rate of establishment without exacerbating potassium and and/or magnesium deficiencies.

Explaining the impetus for the research, Broschat noted that because landscape soils differ greatly in physical and chemical properties from the substrates used in container production, the nutritional requirements are also quite different. “While landscape soils in many parts of the United States are sufficiently fertile that routine fertilization of established woody ornamental plants is not required, in other areas, such as the highly leached sandy soils of the southern Atlantic coastal plain, nutrient deficiencies are common.” Broschat and Moore transplanted container-grown areca palm (Dypsis lutescens) and chinese hibiscus (Hibiscus rosa-sinensis ‘President’) into a landscape soil and performed experiments using different fertilizer treatments.

According to the researchers, although plants of both species had the darkest green color and largest size when continuously fertilized with high-nitrogen fertilizer, this treatment induced magnesium deficiency in both species. Plant size and color for both species were highly correlated with cumulative nitrogen application rates, but also with initial nitrogen application rates, suggesting that high-nitrogen fertilization during the first 6 months affected plant quality at 12 and 24 months after planting, even if high-nitrogen fertilization was discontinued. “Continued use of a moderate nitrogen landscape palm maintenance fertilizer ultimately produced areca palm plants as good as those receiving high nitrogen during the establishment period”, added Broschat.

Chinese hibiscus appeared to grow best with a sustained medium to high rate of nitrogen regardless of the analysis, but only when high-nitrogen fertilizer was used for 24 months did the treatment result in an increase in severity of magnesium deficiency symptoms in one of the experiments. Fertilization with high-nitrogen fertilizer for the first 12 months, followed by 12 months of moderate nitrogen landscape palm maintenance fertilizer resulted in the best overall quality in both experiments.

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The complete study and abstract are available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/20/2/389

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at ashs.org

[Jastin]

Interesting read, thanks! I've always held off from fertilizing at planting due to root shock. If I plant in March, i'll throw a very small amount of fert down in August. I would have thought a higher amount of potassium at first would be better, but even then I don't apply anything other than complete fert down so...

[Pedro 65]

Im not into high Nitrogen at any stage, especially the early stage, your after good root growth early not extra size up top.. I keep it the same or lower than Potassium ....Insects including scale and mealy bugs are very attracted and LOVE gorging on palms fed with High N. Each to their own, I believe what I see with trials in my own ground not whats written on paper

[_Keith]

It my alluvial silty clay loam soil it is unlikely I would have run into any nutrient deficiency to start with, but for the last few years I have used palm fertilizers anyway. Most of them are geared to Florida specs anyway where nutrient leaching is a much more serious issue. This year, I intended to pump up the nitrogen volume. In addition to the palm fert, I am gonna add Ammonium sulfate to double the n factor.

[sonoranfans]

In sandy soils, I would think its better to maintain nutrient levels over time than to spike the soil and not control nutrients over time. I have had pretty good success with liberal applications of florikan time release palm fertilizer 8-2-12, supplemented with fish fertilizer(4 1 1) as a soil conditioner and humic acid to chelate and kill bad nematodes. the florikan fert is expensive but has been engineered to deliver consistent levels of nutrients over time in high drainage sandy soil. In clay soil things are much easier and the florikan engineered time release is probably not needed. My 3 gallon mule palm, was just going pinnate at ~1 1/2 feet is now 8' with a trunk 8-9" at the base in 27 months. I also have a bismarckia that has gone from a sickly 5 gallon 2' overall, 1 spear 2 fronds to 8' tall and 8' wide with ~ 15 fronds. My fastest fan palm has been livistona decora 5 gallon 3' to 10' overall in 2 years, while my archontophoenix alexandre have been my fastest palm 1 gallon 2' to 10-11' overall in 27 months.

[sonoranfans]

It my alluvial silty clay loam soil it is unlikely I would have run into any nutrient deficiency to start with, but for the last few years I have used palm fertilizers anyway. Most of them are geared to Florida specs anyway where nutrient leaching is a much more serious issue. This year, I intended to pump up the nitrogen volume. In addition to the palm fert, I am gonna add Ammonium sulfate to double the n factor.

I would wattch that ammonium sulfate, definitely not time release and will increase soil acidity a bit. If your soil is on the basic side a gente application shouldnt be a problem. If you are already acidic, it could cause bioavailibility issues for Mg, Mn, Fe among others....

[_Keith]

It my alluvial silty clay loam soil it is unlikely I would have run into any nutrient deficiency to start with, but for the last few years I have used palm fertilizers anyway. Most of them are geared to Florida specs anyway where nutrient leaching is a much more serious issue. This year, I intended to pump up the nitrogen volume. In addition to the palm fert, I am gonna add Ammonium sulfate to double the n factor.

I would wattch that ammonium sulfate, definitely not time release and will increase soil acidity a bit. If your soil is on the basic side a gente application shouldnt be a problem. If you are already acidic, it could cause bioavailibility issues for Mg, Mn, Fe among others....

Soils here run around 6.5 on average. Thanks for making that note. Ammonium nitrate, my preference, is hard to find lately because of certain other uses. I do have some lime in the shop from a few years back. Perhaps I'll spread little along with Ammonium sulfate to help buffer the ph.

[sonoranfans]

It my alluvial silty clay loam soil it is unlikely I would have run into any nutrient deficiency to start with, but for the last few years I have used palm fertilizers anyway. Most of them are geared to Florida specs anyway where nutrient leaching is a much more serious issue. This year, I intended to pump up the nitrogen volume. In addition to the palm fert, I am gonna add Ammonium sulfate to double the n factor.

I would wattch that ammonium sulfate, definitely not time release and will increase soil acidity a bit. If your soil is on the basic side a gente application shouldnt be a problem. If you are already acidic, it could cause bioavailibility issues for Mg, Mn, Fe among others....

Soils here run around 6.5 on average. Thanks for making that note. Ammonium nitrate, my preference, is hard to find lately because of certain other uses. I do have some lime in the shop from a few years back. . Perhaps I'll spread little along with Ammonium sulfate to help buffer the ph.

I would still be careful as lime takes a while to shift soil pH and the ammonium sulfate is just about immediately soluble. Why not try some fish fert?

[Jose Maria]

Fertilization is a very complex issue, we need to analyse the soils before making any asumptions.

Also containers are just a limited amount of soil, once transplanted we have tons of soils to take into account.

It is easy to overdo the nitrogen fertilization, sulfur-coated urea is a nice slow release N source.

I have observed with good results in oilpalm-nurseries , that aplying just about every element as fertilizer gives good results, just in case something is missing, the costs are small, and the palms do fine.

After transplant things are different, now economy has to be considered.

Edited December 31, 2012 by Jose Maria

[kahili]

Being in a colder environment, where there is only a certain amt of growing months in the year, I do go with a higher nitrogen level with palms in the ground. I use Multicote 18-6-12 controlled release which is good for 6 months and I apply it in May when the soil temps are warm enough to utilize it. It has all the minors in it. I only do it once a year, and that takes me to October. I have clay soil, so there is also plenty of nutrients as well as the layer of composted leaf mulch that I try to put down every year or so. The more leaves you have, the more roots you get and vice versa, so I want a higher nitrogen number-but I also want it to release throughout the 6 months of growing that i do have.

Jastin, I am just wondering when you refer to "root shock" and transplanting-are you talking about digging a palm out of the ground and replanting it or just taking a root bound (or not) palm out of a container and planting it? Because "root shock" only occurs when it is the former, because you have cut and disturbed the roots to such a degree. Just planting a container palm where the roots are not disturbed will not shock the roots-and I would go ahead and fertilize the planted palm. Assuming that you are not taking a container palm from shaded conditions and sticking it in the full sun where there will be shock (to the leaves) etc. The palm is actually better off in the ground if its rooted enough and will take up that fert. Even with palms dug up, I would not wait 6 months, if you did it in March, because the roots are going to start growing again within a month if the temps are warm enough and the palm would benefit from some fertilizer a month later. I would do a smaller amt than normal, but it will help the palm.