The last few years I have really struggled with boron def. in pansy plugs, so this year I have started to add a boron supplement. The problem is that I don't know how much to add. I saw on several edu sites that .75 0z/100 gal of Borax was the correct amt-but it never says how many times-or is it just once? I started with the boron applications when the pansies were starting to put out true leaves. I have been adding .40 oz/100 gallons water of borax to the fert mix and gradually fertilizing more as they grow larger, increasing the ppm of the fert (20-10-20 mostly, switching to 15-2-20 occasionally) but not the borax amt. I think that I may be using too much because I am fertilizing them every day now (seeds started 8/9), but I am seeing a lot of boron def. in the plugs. This late germination is mostly D. Cool water and D. Primrose, and while I have found that blue is the biggest problem when it comes to b. def, I am seeing it in the primrose as well.
Usually its been the extreme heat when germinating that causes the boron def (that I can see), but this year the heat was not as big an issue in August as previous yrs.
If the plug is exhibiting a b. def-will it ever come out of it with continuing boron applications or should I discontinue the borax?
How many times do you guys apply boron to your plugs and at what stages?
Thanks in advance for all the help you can give.
Your Boron problems are probably not low Boron in the media but elevated ph blocking its availability. Make sure your ph is 5.8 or lower.:)
Eric-I should have said that the ph is about 5.8. The leaves are nice and green-no blocked iron, I think it is Boron def.
Check your E.C. to make sure that's not above 1.2. Higher E.C.'s can add to the Boron problem.
If your media ph is 5.8 fully drench (some leaching) with a .5 ppm of Boron with water having a ph of around 4.5. Follow with a rinse of water with a ph of 5.4-5.6. Check E.C. again before next watering to see if fertilizer will be needed. Apply a .25 ppm once a week or about .125 ppm constant.
Thank you so much Eric-I think the E.C. levels are too high and that is the culprit. Will drench right now. I always really appreciate the help that you give.
So if I were starting from scratch-you apply .25 ppm/weekly from stage 2 onwards? That is what is not really clear from the edu sites. Or is the ppm suggestion low because I have already added so much? The sites say 6ppm-just not how many times or when in the growing stage to do it.
You can go all the way up to 6 ppm one time as a corrective. Make sure you rinse really good especially if you doing it with extremely low ph water. I usually apply .125 -.25 ppm constant. Remember this saying, "When in doubt leach it out".;)
We apply supplemental Boron every two weeks the entire time the crop is one the ground. For rates and other support info, I high recommend contacting the folks at J.R. Peters. Jack, Cari and their team are excellent. There are probably other great labs too, but I'm a Jack's fan - they've never steered me wrong. Good luck!