Q. I know that this is not the time of year to fertilize plants, but I have a few questions regarding that subject now that it is on my mind. Do you have any suggestions for good way to apply fertilizer to plants that are in rock mulch? It’s somewhat of a hassle to move the rock from around the plants, apply granular fertilizer, work it into the soil, and then replace the rock. I’ve used Miracle-Gro for foliar feeding, but they recommend that you feed the plants every 7 – 14 days. Is there another liquid option that only needs to be applied once or twice a season?
A. Let’s cover a few options that you can use to fertilize plants in rock mulch.
The liquid drench method. You can take a fertilizer which is soluble in water and dissolve it in a bucket of water and apply it to the root area where it is irrigated. This works very well with iron products that should be applied to the soil provided the product dissolves or is suspended in water.
The dry fertilizer drench. Apply a dry fertilizer to the rock mulch between the plant and its source of water. Take a hose with a nozzle and wash it into the mulch. Make sure the fertilizer is not applied too close to the plant or the fertilizer might damage or even kill a plant.
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| One type of fertilizer stake with a plastic cap for driving the stake into the wet ground with a hammer. |
The fertilizer stake method. Take a fertilizer stakes and either push them or hammer them into the soil after an irrigation and in the area close to the source of water. Of course you will use the plastic cap that comes with the stakes when you hammer them into the soil.
Foliar applications of fertilizer. This works quite well but as you mentioned it is short-lived compared to a soil application. Make sure you use a wetting agent with the foliar spray.
Install a fertilizer injector. These can be very pricey. Remember that with an injector the fertilizer is applied in proportion to the amount of water that is given to a plant. Those plants which receive more water, receive more fertilizer. It is important to have an irrigation system which applies to water correctly if this is to work well.