If you read my article about 6 weeks ago, I figured it’s time for an update on how my fertilizing is going. The answer seems to be A-OK.
Just to recap: When I put the soil in the planter, I sowed it with a slow-release organic granular fertilizer (7-2-5). Though there was dolomite calcium included in the mix already (because it was an 80% peat, 15% perlite 5% vermiculite mix). I did add additional calcium in the form of a half of a crushed eggshell at the bottom of the hole when I transplanted my tomatoes and peppers.
I have read a lot of issues with salts collecting in the resevoir, so I opted to fertilize top-down and with foliar sprays. This was also good because it allowed me to control what plant got what fertilizer.
During the spring and up until I got to the first few days of June, I stuck to a very neutral fertilizer in the form of organic fish emulsion (4-1-1) at root-application strength. I applied it once every two weeks to everything in my planter: spinach, onions, lettuce, cucumbers, tomatoes and peppers. Did the plants need it? I don’t know. I grew a pretty lush jungle in my spinach crops, and certainly nothing looked like it was lacking or getting burned, though I did suffer some pest problems (my fault, through ignorance).
At the beginning of June, I set a slightly different course. We had a warm spell, and my spinach bolted. Well and fine, I pulled it and did a little careful turning up of the earth with a trowel to get the worst of the roots, and stuck my dill, sage, and rosemary in its place after I refreshed the soil with another light sprinkling of the 7-2-5 slow release. I stopped fertilizing the greens with the fish emulsion, as they were already growing to huge profusion and did not appear to be suffering in any way. They still look fine at 30 days without additional deliberate fertilizing. In fact, my dill plant is collapsing under it’s own weight and is as tall as the tomato stakes. Possibly the best indicator of fertilization needs for the greens are my cukes, which are large, in full flower and haven’t shown any signs of yellowing. So I haven’t worried much about fertilizing them– I gave them another sprinkle of SRF and let them be.
In early June, my cherry tomato plants began to develop flowers, and so after much dithering and shopping at several different locations, I ended up somewhat unhappily with Miracle-Gro 2000421 Tomato Plant Food – 1.5 Pound (18-18-21). I wanted something organic, and I wanted something that was low in nitrogen, and high in phosphate and potassium, but it wasn’t to be. This is on my to-do list for next year. I fed the peppers, tomatoes, and strawberries only in a top-down format lightly at the roots with about 1/4 scoop in a 2L watering container every 7 days on Friday.
I also put 1/4 tsp of epsom salts in a 1L spray bottle of water and have been applying it as a foliar spray on the peppers and tomatoes since they’ve started blooming. In case you’re unfamiliar with fertilizing with epsom salts, it contains magnesium and sulfur which benefit tomatoes and peppers during fruit production. Most places suggest only supplementing with epsom salts if you’re in truly magnesium deficient soil. I’m in sterile potting mix for the water wicking, and as I’ve read over and over again that plants growing in such a mix will require everything it gets from the gardener, so I figured that there was a good chance I’d be doing no harm. I couldn’t find out how often to fertilize plants this way when they’re growing in sterile mix, so I’ve kept it pretty light: a couple spritzes per pepper plant and three or four on the tomatoes (which are considerably larger) every 7 days on Wednesday.
The tomato and pepper plants appear to be doing well on this regimen; the tomatoes may be doing a little too well on this high nitrogen mix, as they would have taken over the planter in one spare month with leafy green. But again, if some things are doing too well, nothing appears to be suffering or burning. I find new suckers to prune on the tomatoes every few days, and I’ve counted at least 2 dozen bunches of green cherry tomatoes hanging between pea and 1 inch size, with at least 3 dozen more bunches of flowers in bloom. It’s a little awe-inspiring to see how much my three spindly transplants have grown and are threatening to produce. Nothing has ripened yet, but I anticipate soon there will be red tomatoes on the vine.