The last time I poked my head into a root tab thread here, it almost got chewed off. That is because I use Jobe's spikes. You cant get much cheaper. If you are interested do a site search on them here to see the pro's and cons etc.
I will say I spent about 25 bucks 5 years ago to get the fern and palm spikes which are hard to find in the N.E. but easy in FL. I still have over 50% of what I got. If you can't find them, look for the the houseplant ones. However, be sure to avoid anything that contains any herbicides, insecticides or fungicides.
I also use the prior version of the API which were called Root tabs with iron and were more of a micro fert. But my supply of these is dwindling.
I will say I spent about 25 bucks 5 years ago to get the fern and palm spikes which are hard to find in the N.E. but easy in FL. I still have over 50% of what I got. If you can't find them, look for the the houseplant ones. However, be sure to avoid anything that contains any herbicides, insecticides or fungicides.
I also use the prior version of the API which were called Root tabs with iron and were more of a micro fert. But my supply of these is dwindling.