How much fertilizer to use?

I am currently using Dyna-Gro Foliage Pro 9-3-6. How much fertilizer do I use daily in a watering can that holds approx. half a gallon of water? (picture of my plants listed below if need to know what kind of plants) Cacti use different dosing and frequency? What about my other plants? snake plant. christmas cacti. air plants.

I have been using approx. 0.3-0.4 cc/mL of Foliage Pro per full watering can in the morning and just a quick watering in late evening with no fertilizer. Am I over doing it? Under doing it? Is ok? I would prefer not to kill my plants over time nor waste excess product. (I am using 0.1cc/mL daily for my outdoor cacti and a few times a week only for my indoor snake plants.) What is optimal?

I also want to thank this forum for teaching me much more about container gardening than I ever thought was possible. I am slowly converting to using gritty mix and 5-1-1 mix for my indoor and outdoor plants. Below are a few of them.

1. Plumeria and 2 Maples (the one on right only had 3 leaves when I bought it) - in 5-1-1
2. Unknown red flower. Using store potting soil and has been attacked multiple times by caterpillars, but has kept coming back and blooming hard for 2-3 months thanks to almost daily use of the above fertilizer.
3. Lewisia. First attempt at gritty mix. (Too coarse.) Once cacti didn't survive. Learning experience. Have since bought 1/4 screen, but rather not mess with this for now. Mix is heavy for hanging pot. lol
4. Indoor plants. Umbrella plant finally surviving with first attempt at 5-1-1 soil mix (too coarse but is doing fine). Baby snake plants in gritty mix. And baby christmas cacti in 5-1-1. Larger snake plant not repotted yet into gritty mix. And my 3 air plants. :)

Those are the plants that I am trying to figure out dosing of fertilizer for.

Thumbnail by Mothi Thumbnail by Mothi Thumbnail by Mothi Thumbnail by Mothi
Bay City, MI(Zone 6a)

Where do you live and how did you make the soils so you need to water 2X/day?

How often and at what strength you use the 9-3-6 depends on what soil you're using and your watering habits. In summer, I usually watered weekly and used about 4-5 tsp in 2.5 gallons of water. During the winter with plants under lights, I use 1/4 tsp per gallon every time I water, but I'm flushing the soil each time I water to the degree that about 20% of the total volume of water applied exits the drain hole. Plants that are dormant or quiescent need no or very little fertilizer. E.g., plants that have a winter sleepover in the garage don't get fertilized until I'm sure soil temps are above 55*. A hibiscus or brugmansia snoozing it's way through the winter on the basement floor wouldn't get any fertilizer until it starts pushing growth in earnest, come spring.


I live in Orange County, CA. Outdoor plants are kept on the E-SE side of the house. Plants are usually in shade by noon, or 1pm latest.

For example, my maple trees are in 5-1-1 (fir bark/perlite/peat moss). Every morning I water them (with about 0.4cc Foliage Pro per half gallon water) until what might be 10% volume or more starts pouring out the bottom. During the hot part of the day, they are sheltered away from the sun and away from most of the hot dry winds. By evening of hot, dry wind days my paranoia kicks in and I give the maples a quick splash of water. Not enough to cause water to pour out the bottom. The plumeria has the same mix as the maple, but my paranoia doesn't kick in as much as it does with the maples. I think the plumeria had more peat moss in the batch when mixed.

Another example is my Lewisia 'Elise' which is in a hanging planter that is close to the house under roofing (so it doesn't get rained straight down on). I used screened gritty mix (fir bark, volcanic pumice/lava rock mix, and granite chicken grit) in both hanging planters. (I could not get turface and figured pumice with lava rock mix should hold water. Or did I mess up there?) When I water them in the morning, the water runs through them completely that I sometimes wonder if any water is getting absorbed. So I naturally worry that the plants are too dry. On extra hot/dry days I give them a quick sip of water when the evening when the shade is over them. I have already killed 2 of these plants, but 3 appear to be doing well. Only 1 plant died from each batch I bought.

Should I only be fertilizing once a week and not daily as I have been doing for the summer time for outdoor/indoor plants? Some of my indoor plants will probably be kept under light for the winter if dormancy isn't required. So they would get approximately 1/8 tsp per half gallon watering can, daily.

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