View Full Version : Biostimulants + Wetting Agents + Micros for Summer Stress in VA.

05-07-2002, 12:33 PM
Need recommendation for a Summer Stress fertilizer application on some high profile homes (10,000 square feet, partial shade, couple big thinned Silver Maples, good turf) Northern Virginia location.

Biostimulants: http://www.rootsinc.com is the only one I know of. Humic Acid touted as great for turf.

Wetting Agents: What are these?

Micros: Fe, Maganese, Magnesium, Calcium, Sulfur, Copper, Zinc. Is there a granular mixture for these?

Sulfate of Potash: helps grass grow thicker blades to resist drought/heat?

What I have done:
March-IBDU 1.2lbs N/M
April-Lebanon 5-5-20 Dimension .25N/M

June-Rockland Preferential Treatment
July-Roots 1-2-3 (Roots AGRIplex2 + ironRoots2 + NoburN2)
July-Sulfate of Potash 0-0-50 (makes the grass blade thicker for summer stress)
August-Organica Microbial lawn Booster
September-Lesco Novex 18-2-18 2%Fe .9lbs N/M
November-Lesco 34-3-11 20%SCU 1.7lbs N/m

Alternatives: What else is out there?
Lesco Bolster instead of Roots 1-2-3
Lesco Chelated Iron + instead of Preferential Treatment


05-07-2002, 07:30 PM

The wetting agents (we sell LESCO-WET) that must be applied monthly are very cheap but will require a great deal of labor. Others (we sell LESCO-FLOW) may be applied at much higher rates, but need only be applied twice per year. They need to be applied prior to the occurence of drought conditions. Applying during drought stress periods will actually increase stress on the turf. They help to manage moisture by helping soils utilize water better. Dry soils typically resist moisture in the short term. Summer months often bring about short, infrequent bursts of storm activity that is mostly wasted to runoff. Properly managed soils will percolate better during these periods allowing the turf to use the water that might otherwise run off. In some cases, I've seen LESCO-FLOW improve percolation so much that puddles on athletic field began to drain away without expensive drainage work. This only works in some conditions, particularly older sand based fields that have been under managed.

Most bio-stimulants (including those you mentioned, contain at least some (yet very little) naturally ocurring wetting agents. These are no substitute for the better wetting agents, but they do help. Biostimulants aren't regulated by the same governing bodies that regulate the regular fertilizer industry. In other words, manufacturers can & do make some pretty wild claims about their products. There is no evidence whatsoever that amino acids beneift plant roots in soil. Yet some companies will list insane elements that vitually all plants produce in abundance yet none use or obtain from the soil solution themselves. I would love to see some regs here but the feds don't seem interested. Humate are very benficial. So I encourage my customers to analize the labels for actual humate/iron content, then divide the price per case by the weight of valid beneficial elements in the case. This is usually an eye opening experience. After removing the water, the total humate content is usually nothing compared to the amount of good compost we can fit in a wheel barrow. But again, they do help plants so I have nothing bad to say about the better formulations.

Higher potash level as you are using are a biggy in my book. Anything that improves root density will help get your turf through drought.
Carefull insect & disease management is important too, since many pests are mistaken for drought. Limit traffic & don't mow dormant turf (especially at midday) will also help.


05-07-2002, 08:43 PM
Lot of good questions and I can't answer all because I don't know all those products. I have one major comment off the top and that is about 3 lbs of N from Nov-March. Way too much for what I know. Rutger recommends about 1/3 of your N in the early part of the season and 2/3 in the later part.

I'm trying to keep my N at 3.4 - 3.6 lbs/yr with about 1.8-2.0 Mar thru Aug in 3 apps and the rest Sept-Dec with Sept/Oct being 1-1.2 lb/N.

My last app is ag grade fert witha micro package.

That may change this year as everything from now on I have custom blended. Next 2 rounds will be 3parts N to 2 parts K, 50% each of Muriate and Sulphate of Potash. It will also be 65% CRN.

Certain forms of N will impart better color to turf so I won't be using iron but I'll keep my mind open as I could add 2% to my blend.

Wetting agents=surfactants. Makes water wetter, in other words it doesn't bead up and will penetrate hard soils and organic matter equally as good soil. Used to eliminate localized dry spots. I may use some this year as we are severely restricted on our watering and it would help every inch get penetration.

I'm not real fond of iron granules as I had to pump and repaint a pool one time from the iron spots.

05-09-2002, 09:49 PM

think balance. Potassium is good for heat, drought & cold tolerance, but adding in July may be too late for the plant to use in summer heat/drought. Apply your potassium before the need. Also, University of Wisconsin did a study that showed grass will up-take more potassium if the P:N ratio is greater or equal to .75. This means you get more bang for your buck if you use a balanced fert with N & K. One more thought. What is the pH of your soils? Are most soils out east acidic? Sulfate of Potash will lower the soil pH. Use Potassium Nitrate instead. It has N & K and will not lower your soil pH.


05-09-2002, 09:53 PM
That last post should be directed to jmarkwood, not HBFOXJr. My appologies to HBFOXJr.


05-10-2002, 07:07 AM
Potassium is also soluble like nitrogen and needs to be put on in regular amounts. A large dose will help a deficient lawn get a jump start but if the fertility level is generally OK some of a large dose is down the drain so to speak.

05-10-2002, 07:20 AM
Are you saying for the most bang for the buck in a balanced fert the potassium should should be at least 75% of the N level? If so what has happened to the 3-1-2 or 4-1-2 that our cool season and transition turf like in much of the country? Can you post a link to that Wisconsin study. I'd like to learn more.

Here is more info on potassium. Plant and Pest Advisory (http://www.rce.rutgers.edu/ppa/2002/ln0418.pdf)

This is the link for he newsletters and other good things Rutgers University (http://www.rce.rutgers.edu/pubs/plantandpestadvisory/)

05-10-2002, 08:29 AM
HBFOXJr writes: ..."a large dose (of K) is down the drain so to speak."

Very good point! The maximum rate for potassium in a single app is 1.5 lb./M.

I don't have a WEB link to this university study on potassium. This information was presented to us in our Soil Science class. The professor is the Hort dept. chair, ex University of Illinois Extension Service Agent and grad of U of I and U of Wis. The results of the study are that greater potassium is absorbed if the ratio of K:N is 0.75 or greater. In other words 1 lb. N/M plus at least 0.75 lb. K/M (in this example). Same study also noted a relationship between N & P absorbtion. Here the ratio is P:N greater or equal to 0.25. I'll see if I can get a link to the actual study.

Also, plants will absorb more K than needed if excess K is present in soil solution. This is know as luxury consumption. Plants do have an ability to store this excess K for future use.


05-10-2002, 09:18 AM

I don't think that the 312 or 412 guideline is obsoleted by this study. It results in a P:N ration of .33 and K:N ratio of .67. There is potassium held in your soil and that will alter the potassium levels in soil solution seen by your turf. I do think that a 413 ratio is a better choice. Also, the major message here is that just dumping K on a soil that is low in potassium helps, but putting down N with that K is better.


05-10-2002, 04:25 PM
Lots of things go better with N. Look at iron and broadleaf weed control. Both work better with a little N.

05-10-2002, 06:18 PM
I'm enjoying this one.

I've also tried to observe more than participate due to time constraints. So I'll just toss this one out for the sake of consideration.

Different N & K sources will have different solubility levels. Soils have differing CEC's as well. So to advise on N-K ratios must also consider these variable factors as well.

Irrigation rates impact both as well.



05-10-2002, 10:32 PM
I guess that that is why the 312/412 fertilizer ratios are guidelines. You must analyze each situation differently and make the right choice based on an individual lawn's needs.