We are having a problem with our Peterstar Pink and Marble. Primarily in our 5 br. No other plant dates or varieties were effected. We sent in a tissue sample to the Fafard lab and received the results. Dr. Poole suggested a leaching, for the higher Boron readings. Looking at the plants, leaves are cupping and look like a deficiency in Calcium(as seem in the 2004 Ecke Poinsettia Manual page 104) however tissue readings are 1.16, normal range ( Magnesium reading were at .83%). The effected leaves are newer as well as half way down the stem. Other Nutrients that came back high are Phosphorus .93%, Sulfur .57%, Zinc 82ppm, Boron 102%. Our water supply carries high Boron. We also monitor our alkalinity and PH. Other nutrients seemed to be in the middle of acceptable ranges. We seem always to battle low manganese. One of the previous fertilizations did include STEM. We are now back to our leaching before fertilization, having just completed a Safari drench program. We are fertilizing at 150 ppm with 15-5-25 poinsettia fertilizer with always adding either a 100ppm Cal-Nitrate or 100 ppm Epsom salts. I can find plenty of pictures of deficiencies not as many as toxicities. Any thoughts would be welcomed.

Jim, Though your calcium foliage levels appear in the normal range I wonder if your crop is getting enough calcium? There is an antogonism between calcium and magnesium from what I have read and if one is too high in the soil it can prevent the uptake of the other. I have high elemental calcium rates in my well water at 140-150 ppm, feed calcium nitrate every 4th-5th. watering, yet I still only use 30-40ppm of magnesium in my feed mix. I wish my well water was not this high in calcium but is just something I have to deal with all the time. Other crops besides Poinsettias never get fed additional calcium nitrate due to this high level of water calcium but my Poinsettias seem to thrive on the extra calcium. I wonder if your use of 100 ppm of magnesium in your feed mix in the form of magnesium sufate is ok. That rate of magnesium seems really high to me and may be preventing calcium uptake. I know there have been articles written in the past stating that those with high calcium in there water should feed magnesium at 50% the rate of calcium but myself and other growers in my area have found that an excessive amount of magnesium that is not necessary. Can you post the whole report? Below is a current picture of a Peterstar White and Peterstar Pink being fed the roughly 140 ppm calcium and 30-40 ppm magnesium at every watering with a soil pH right at 6.0.....Michael Pawelek
PS- A soil test taken at the same time as a tissue test can reveal problems not seen with just a tissue test or soil test taken alone.

This message has been edited. Last edited by: Michael Pawelek,

Hi Jim -

Did you have a media analysis run at the same time? It would be good to see what things look like in the soil as well. pH always gives a good idea of what nutrients are being supplied - if the pH is out of range something could be tied up in the soil.

How are the root systems?

When you took samples for the tissue analysis did you include new foliage? Because calcium is an immobile nutrient many times levels can be fine in the older foliage but the new foliage can actually be deficient.

So it looks like you are usually supplying at least 250 ppm nitrogen with every irrigation, is that correct? Remember Peterstars are a light leaf cultivar and light leaf cultivars are more sensitive to nutrient disorders and require about 20% higher fertility than the dark leave varieties. Peterstar will benefit from an occasional booster feeding if you are routinely feeding it at the same rate as the dark leaf cultivars.

I tried several times to send the soil and tissue results as you can tell without luck. I also sent some pictures of the plant. The plants are looking like they are begining to come out of the problem. However I would like to have an understanding for next time. I can see the results of the high Boron on the lower leaf burn. We are in a soilless mix very simulair to Scotts Metro 510, 40%+ in bark. Here is the MEDIA results. 5.2 pH, 2.30EC, 0 NH4-N, 155. NO3-N, 19.4 P, 162.4 K, 136.7 Ca, 96.8 Mg, 69.1 Na, 91.1 S, .69 Fe, .53 Mn, .11 Zn, .05 Cu, 1.06 B, 0.00 Mo, .62 Al, 16.2 Si

In looking at the soil results please keep in mind that three previous watering there was no leaching and the first one did have the STEM added to the balanced fertilizer. Tissue samples were taken from newer growth as well as older leaves. In fertilization our habits have been green leaf varieties a total of 350 ppm nitrogen and dark leaf receive 250 ppm. We bring these levels down as the days get shorter and the plants acheive their height goals. This week we start our Calcium Chloride weekly spray program. Michael and Ecke thanks for the quick response and your thoughts.

Jim, It looks like your pH is really low which will radically slow the calcium/magnesium available to the plants even if they are present in the soil. If the calcium is more available at a higher pH it will also tend to tie up some of the excess sodium in the soil. Your Moly and NH4 nitrogen are non existant and very important for proper growth. I realize that further North you do not want a lot of NH4 in the soil during cooler/cloudy weather but most plants grow healthier with a combination of NH4 & NO3 than either one by itself. I also add extra Moly. to my liquid feed in the form of ammonium Molybdate I buy by the 1/2 pound and use 3-4 PPM all during the crop. At this point correcting the pH and adding some Moly and NH4 nitrogen might help. Hopefully the Ecke team will give better recommendations. For next year try to figure out why these particular poinsettias are different from the rest of the crop, for example the soil mix blending process or initial pH? Also you might want to spend some money and get a soil and tissue sample now from another part of the crop that is doing really well to get a handle on what pH and range of elements makes for a quality crop with your soil mix, water and growing conditions. Knowing what makes for a great poinsettia at your nursery will go a long way for changes next year.....Michael Pawelek

Hi Jim -

We also looked the pictures, thanks for posting them. The plants actually look pretty good and we don't really see the cupping you describe so it looks like the situation is improving...let us know if we are wrong. We can see the marginal burn which could be from the high level of boron but also your sodium levels are a little high. Raising your pH will help with the excess boron. The excess sodium is probably from your water source and there isn't anything you can do about that except to make sure you aren't letting the plants dry too much between irrigations.

The biggest issue is the low pH and bringing the pH up should help matters. Are you acidifying you water? If you are maybe you need to recalculate the amount of acid you are adding as it may be neutralizing the alkalinity too much and reducing the pH too much. Some other things to consider that contribute to low pH would be:

Insufficient lime charge to the substrate – Do you know what the pH of the new substrate before planting would be?

Buffering capacity of the mix is too low - If you are mixing your own soil you may need to evaluate the amount of preplant lime added.

Substrate components have a naturally low pH – you mentioned the mix is soilless with bark. Pine bark is acidic and the pH of the media will be more acidic the more bark you use.

If the low pH can be attributed to the initial pH of the media before planting there isn’t much (besides a flowable lime drench to increase pH) you can do this year to correct the situation but it will be important to evaluate all these factors for next season and make necessary changes to the preplant amendments.

If your pH is low because of your water source and too much acidification that’s easy to correct by recalculating the amount of acid needed.

Hope this helps…again unless we are missing something in the pictures the plants look pretty good so any drastic changes are corrective treatments may not be needed.