Hello fellow gardeners!

I've searched through these forums previously but have just officially became a member today. :) I wish I was joining under better circumstances b/c I think I've damaged my plants and am really hoping to bring them back!

For starters - here are the different types of plants I am referring to: Dieffenbachia, Sansevieria, Mandevilla, small Zebra and Rubber Plant.

An ill fated bag of cactus/palm mix soil was purchased from Home Depot about 2 months ago which brought with it fungus gnats...I threw out the bag and began researching online what these annoying pests were. When I found out that they reproduce at such rapid rates and could be living inside the soil of my existing plants, I decided to repot them - I've owned them since roughly September 2012, and pretty much left them alone over the winter. I was thrilled to see new growth coming from each one of them even though I felt they were a bit neglected so I decided to research the best options for potting soil used in containers.

Roughly 2-3 weeks ago, I found a website that offered a mix/blend of materials I could actually find locally and went to work on my container garden! This mix consisted of:

Base = 8 qt. Gardener's Pride potting soil and 8 qt. Hyponex (Scott's) potting soil w/self feeding nutrients lasting up to 4 mos.
Added = 1/4 c of Expert Gardener Plant food, 1/4 c Gardener's Organic Lime and 8 qt MG Perlite

I was so proud of myself and how wonderful this soil blend looked compared to the previous Cactus/Palm Mix and thought I was doing really well! Until the last week when I noticed my Dieffenbachia was becoming yellow on one of his largest leaves and the others showed signs of brown tips (including the newest baby leaves that were just sprouting).

I examined the other plants from the list above and noticed similar issues - my Rubber Plant's newest leaves looked wilted, the Mandevilla had fully yellowed leaves in random spots, my Zebra plant's leaves were half brown and even the Sansevieria was getting brown around his edges. Back to the internet to research possible causes - I thought it could be spider mites and wiped down every leaf on each plant and just under the possibility that it could be over-fertilization, I leached the Dieffenbachia and Rubber Plant (although I was concerned of root rot and/or more fungus gnats).

Yesterday I noticed that the yellowing was coming right back to the leaf tips of the Dieffenbachia and I decided that the possiblity of these guys being over-fertilized was very real especially when I looked back and realized that I added plant food to the soil mix that already contained plant food in it (Hyponex).

I am desperately trying to save these guys! This morning I removed them from their pots and potentially harmful soil, rinsed off their roots (which some already were just falling off) and went back to the store to buy new ingredients for my soil mix. I've seen Al's gritty blend but not only am I in an emergency state to get these guys new soil, many of those ingredients are not easily found. Plus I've spent so much time online reading various websites/forums advice that sometimes seem to contradict each other, that I decided it was finally time to put my specific plea out to any of you who might be able to help.

Right now I've got all the plants sitting in a container of distilled water so they do not dry out; I am hoping to get some advice on how to proceed with the soil-mix options available to me before I go ahead and mix everything up. Here is what I've bought:

8 qt of Gardener's Delight all purpose potting soil
8 qt of Orchid Potting Mix (2 bags) - coarse blend
5 lbs of basic aquarium gravel
1 bag of "Kitty Diggin's" fragrance free cat litter

I chose these ingredients based on the various articles I've read and what was or was NOT available for immediate purchase - such as Al's blend - which btw, does anyone know if he sells it pre-made? He would probably do very well with it! ;-) And the store was completely out of Perlite! Just my luck. :-/ I also have a bag of Sphagnum Moss on hand too.

While my little guys soak in distilled water, I'm praying for advice - should I return all of the above and buy different bases for the soil? Will blending the potting soil w/8qt of the Orchid blend, 5 lbs of the gravel and a cup or 2 of the kitty litter work? Are these plants even salvageable? I won't give up on them yet! Any specific advice on how to nurse them back to health?

I've taken pictures of each plant but have not posted them yet in my haste to just get my post online...I can definitely add them to show the exact condition of each plant.

Thank you for reading this long ramble of a post and any/all advice you can give. Say a prayer/send positive thoughts and fingers crossed that I can bring these guys back! ~Angie