Some thoughts on liquid fertilizer

I noticed this week that Beasley's Nursery has a Dosmatic fertilizer injector set up next to their seedling house. This grabbed my attention for two reasons Beasley's present seedlings as well as any garden centre I know (not mine frustratingly, but that's another story) and because I was asked about fertilizing seedlings a couple of times during the week.  Applying some feed to seedlings will become particularly important over the coming months as garden centres try to extend the shelf life of their plants as turn over drops away in the hot months.

We walk a fine line when it comes to fertilizer, too much and plants rush away on us, too little and they stress which can lead to all sorts of other problems.  Realistically we offer seedlings that we expect will last a couple of weeks before being planted out as long as they are watered as needed.  We have a few strategies to achieve this: a small amount of "micro-fine" controlled release fertilizer mixed into the growing media, regular liquid feeding to keep plants toned and a relatively heavy doe of liquid feed as plants are dispatched. To maintain quality plants in a seedling display I strongly recommend continued application of liquid fertilizer.

I recommend Debco Plant Food - All Purpose, it's a well balanced blend that should maintain healthy plants without producing triffids.  Bare in mind that I am not a fan of plant junk food that offers easy green, super green and lush growth. At Scotsburn we use blended liquid fertilizers either Campbell's Diamond White or Krystalon White, fairly obviously they are pretty much interchangeable products from different manufacturers. We use around 1g of fertilizer per litre of water, once a week should be plenty but be prepared to increase the frequency after heavy rain or hot weather when extra irrigation will wash out feed. I haven't tried organic materials such as Charlie Carp but I expect that with a little trialling they would produce perfectly good results... just too expensive for use in our situation.

How is liquid fertilizer best applied.  It's best that the plants are not stressed when fertilizing; not too hot, soil not too dry or too wet. A watering can will do the job perfectly well but will become frustrating if feeding a large batch of plants.  Sage Horticultural has a range of fertilizer injectors, I notice starting as cheaply as $195.00 that simplify the process of fertilizing so that it is just part of the watering process.


A"Venturi Fertilizer Injector", simple, effective and remarkably cheap.