How often you fertilize shouldn't be put to a schedule; rather, it should be on an 'as needed' basis. Frequency depends on the fertilizer you're using, what strength you fertilize at, what type of plant material you're fertilizing, ambient temperatures, how robustly the plant is growing, where the plant is in its growth cycle, and very importantly - how fast the soil is (how well it drains) and your watering habits.

I use a fast soil & the tropicals & houseplants I over-winter get fed a very small dose every time I water. I can do this because the soils I use are fery fast & I'm continually flushing fertilizer salts from the soil every time I water. In the summer, when all my plants are awake, there are too many to fertilize at every application, so I fertilize weekly (or every 2-3 weeks, depending on the conditions listed above) at doses much reduced from the suggested dosages on the label.

The shorter answer. Weakly weekly is a good policy.

Al

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