Feed Your Plants What They Need
OK, who's hungry? Depending on when you're reading this article, your stomach might be growling for breakfast, lunch or dinner. Or my favorite, the late afternoon snack. Not that I always need those chips and salsa at 4:30 p.m., but there they are right there in the pantry, after all. Similarly, I have a garage shelf lined with a variety of fertilizers for my bursting backyard garden. There's the fish emulsion, “rose food,” and the more generic “plant & vegetable fertilizer,” among others. They are all labeled organic and are supposed to be good for something. But do my plants need any of it?
Truth be told, most of these fertilizers end up on my shelf because I am the neighbor that is willing to find a home for everything the other neighbors give away. Old patio umbrella? I'll reuse it. Bought a new gas grill? I'll take the old one to work. Can't take that box of flower fertilizer when you move? I might use it at some point. And so it goes until I have many boxes of many garden fertilizers. But when to use what? Just like us mere humans, plants aren't meant to eat just because there's something in the fridge (I mean garage.) Unlike us, they can't walk over and pick out whatever sounds good at the time. So here's how to give them a healthy serving of what they need at the right time. Also known as fertilizing your plants appropriately:
Let's take the long view here. Compost is a slow-release fertilizer, and slow-release fertilizers are best. It not only adds nutrients to the soil, it also helps to retain soil moisture.
More is not better! It is just more. Too much fertilizer can result in plant damage, excessive plant growth and additional water needs by the plant. And we all know there is no additional water these days. If you use a commercial organic fertilizer, follow the instructions on the box very carefully.
Most woody ornamentals (think nonflowering trees and shrubs) don't require fertilizer, even at planting times. This is also true for California native plants.
Does your plant look unhealthy? Give it some TLC! However, don't assume that it's fertilizer it needs. Unhealthy roots, poor soil conditions or improper care (gasp) are all potential culprits.
Not all plants have the same appetite. Follow plant care guidelines carefully to be sure that you are addressing the individual needs of your fruit trees, vegetables and flowering plants.
Don't – listen carefully here – please do not apply fertilizer directly on the trunk or crown of your trees and shrubs. It's the roots that need the food, and they can be quite a bit further out from the crown of the plant.
And I would be remiss to give fertilizer tips without mentioning the importance of appropriate irrigation. None of this plant-feeding business matters if they are not adequately hydrated. So please be a good garden host(ess) and offer a tall glass of water with that fertilizer.
- Landscape Plants: Fertilizing & Watering: UC IPM
- The California Backyard Orchard: University of California
- California Master Gardener Handbook: Fertilizers.