I may be the exception but I use miracle grow producs. I used to use the regular all purpose miracle grow and just throw it in the container and dispense it threw the hose. When the color gets real light, I just unscrew it and pour some more into the canister and spray away. Naturally, I have a greenhouse. I always water all of my orchids and then hit them quickly with the fertilizer. There is a miracle grow that is meant just for tomatoes,and if I recall has something like a 7-7-7. Maybe not exact but low numbers and almost the same. This is what I now use almost all of the time. Every once in a while I use the all purpose miracle grow just to change things up. Also because it is much cheaper than the tomatoe variety. A few years ago while on vacation in Sept. in South Carolina we went into a Wal Marts and they had it discounted. I bought all that they had and started looking at the other Wal-Marts in the area. Took home enough to last me for years.

Whitecat,

The african violet food is fine, as is the miraclegro. The numbers (7-7-7 and 20-20-20) are interchangeable. What I mean is that they are percent by volume (if I'm not mistaken) once you've diluted them to the package instructions. These are easily manipulated: double your dosage for your african violet food in the same volume of water (1 tsp/half gallon vs 2 tsp/gallon) and you double the concentration of NPK, in this case from 7-7-7 to 14-14-14. So either would be fine. Myself, Im with you Bob, for my orchids I use the miracle gro 20-20-20 both at home and at my nursery I work at, and the plants grow well. Because fertilizers are simple salts (i.e. potassium sulphate) I'm fairly certain they can't really degrade. If it were me, I'd increase your dosage for your plants. That little purple bottle should have been used of years ago if you are fertilizing with any frequency (I use 20 drops per 1/2 gallon for my AV's at work). But then again you do get good results for yourself so if it ain't broke...

And FYI: Epsom salts are really only necessary if you are pushing your plants upper light limits (but short of burning), which creates a magnesium deficiency (yellowing). Chlorophyll, by design, degrades with exposure to sunlight and gets replenished by the hydrolysis of water molecules. If the amount of sunlight coming in exceed the plants ability to replenish the chlorophyll, the plant begins to yellow (this is why you see a lot of higher light plants like Rhyncholaelia look yellowish when they are blooming in many cases). Epsom salts will help green them up.

My recommendation: a balanced fertilizer all year is really all a hobbiest needs. Stick with either the 7-7-7 or 20-20-20.

Thanks, guys. I've doubled the amount of AV fertilizer & crossed supplements off the orchid shopping list. The MG's out - I use a gallon watering can. Even stirring granules in a cup or so of the hottest tap water first doesn't work. I'd still have to stir frequently while watering.

Aside from the AV, Scotts' small number of liquid fertilizers have uneven ratios - one is 8-0-0.

Thanks for the helpful details. WC8

There's a thread on another forum about fertilizer shelf life you may want to read:
http://www.orchidboard.com/community/advanced-discussion/60458-fertilizer-shelf-life.html
As I point out there, some of the components of fertilizers do in fact degrade if exposed to air, heat, or light.

I've been using MSU fertilizer plus a bit of Dyna KLN to stimulate roots:
https://www.msu.edu/~goddengr/publications/publications.htm