Fertilizers Getting Wet & Sticky – What To Do?

Q. We have 3 Grow-Boxes that are 18″ x 30′ and 3 boxes 4′ x 30′.

A local company mixed the fertilizer to 16-16-16 and we used this to make up the  Weekly Feed, using that and Mittleider Magic Micro Mix we ordered from your website.

We used this, plus the Pre-Plant formula for the grow boxes. In the process, we noticed that the Weekly Feed was absorbing moisture. The next day the remaining mixture was extremely wet and congealing into a soupy mix. It will be very difficult to spread it evenly. We put it in our dehydrator overnight but it is not drying out, it’s still very sticky.

Would it be possible to dissolve the mixture and apply it as a liquid? Or do you have any other suggestions as to how to deal with it?

A. Epsom Salt has 7 parts water to 1 part MgSO4, which makes it very susceptible to turning wet. The materials used in making the 16-16-16 may have also had water in the compounds. Many compounds have hydrogen, and all have oxygen.

Mixing gently and keeping cool and dry help avoid getting your Weekly Feed wet. Also, in the future, add 2% (by volume) of Perlite to your Weekly Feed Mix. Perlite absorbs something like 20 times its own weight in water, so it usually solves the problem.

As to how to best use your materials now that they are wet – my first choice is to continue using them in the same way – a 16 ounce can distributed evenly over a 30′-long row (2 in a 4′-wide bed).

You CAN dissolve the fertilizer in water and then apply it to the beds, but if you dissolve a week’s supply of fertilizer and then apply it all at once you are very likely to create a salinity problem and hurt your garden. And later waterings will likely leach it out, so it doesn’t last the week.

If you feel you must dissolve the materials I recommend you first dissolve 5 ounces WF in 5 gallons of water, apply that evenly the length of the bed, and then water normally, until water comes out the bottom of the beds. Repeat that process in two other waterings throughout the week.

And by the way, you need to dissolve the Weekly Feed fertilizer ahead of time, as it is not instantly water-soluble. The previous day is best. What a hassle, huh!. That’s why I prefer to apply the materials directly to the soil and then water them in, even when they’re wet and sticky.

Also, getting wet doesn’t affect the usefulness of the fertilizer – only the ease of use.