Can I create DIY micronutrient fertilizers?

Micronutrients for plant health can be added through home remedies but the amounts should be calculated carefully. Epsom salts provide magnesium and borax provides boron. I recall reviving spent tomato plants with a homemade iron chelate from vinegar and a set of nails. On the other hand, I overdosed on a client's blueberry plants from inaccurate rates on the borax. It is hard to beat soil testing to avoid tragedy!

Mixing practices affect nutrient availability. Remember to use warm water to dissolve Epsom salts before dilution. For iron chelates, vinegar for 48 hours soaking steel wool will provide you with an iron mix that you strain before pouring it into a sprayer. I read that a Missouri gardener burned rose leaves using an undiluted vinegar-iron mix. It is always best to try your DIY solutions on 3 plants before doing the entire area.

Soil testing is still a must. The homemade boron solution I tested was 4 ppm using strips, doubling the safe level for beans. I diluted it with rainwater at a ratio of 1:3 to avoid toxicity. Please spend $20 for soil test kits, they are cheaper than replanting your burned crops.

The effectiveness of the do-it-yourself treatment is pH-dependent. Iron chelates with vinegar are most effective in alkaline soils. The use of rainwater in acidic soils is recommended over vinegar to avoid pH crashes. I had a client who experienced great success with iron sprays made with rainwater on their azaleas. The azaleas turned yellow when they switched to spray with tap water because the high pH neutralized the solution.

Read the full article: 7 Essential Micronutrients for Plants: Complete Guide