We’ve just been through the year’s double-barreled peak season for feeding people we care about. Now it’s time to think about feeding our plants.

People, especially our children, make it plain what they like to eat, and when and how much. Our plants, however, take much longer to make their wishes known, and then only by failing to thrive, leaving us wondering what we ought to have done, and when.

It would be oh so very simple if we could just go out, during a preferred season, and feed everything in the garden with varying amounts of the same plant food. Some people do this. And many plants do very well on such a routine. But not all of them, and few do as well as they might if we would pay more attention to their real needs.

Choosing the right fertilizers, and knowing when and how and how much to apply, isn’t simple. I am presently searching for muriate of potash, to turn my hydrangeas blue, or bluer than they were. (They have always been blue, but last spring, for no apparent reason, they all bloomed pink to mauve.)

And I need to fertilize lightly all the daffodil beds, as the new tips come through the ground. Plus, I’m searching for some answers about using lime to improve the sad state of our lawn. To start the new growing season right, I’m prepared to travel outside my local area to stock up. But I don’t really know all the answers, and not always all the questions.

If you garden at all, you are well acquainted with the letters NPK and their accompanying numbers. We’ve learned by osmosis what they indicate, but what do they really mean? N stands for nitrogen, which feeds plant foliage. P stands for potassium, which produces flowers and fruit. K stands for phosphorus, which keeps plants healthy and strong.

What plants prefer which of these elements in abundance? Your lawn, obviously, needs lots of nitrogen. So do the vegetables in your garden, except for the tomatoes, which will be all lush foliage and no fruit if they are over-dosed on nitrogen. Annuals, especially, and perennials, need a big dose of potassium, to produce as many flowers as possible in a compressed growing and showing season. Tomatoes want that phosphorus.

Some people, including some of the best gardeners I know, just sprinkle a sparing amount of a balanced fertilizer, such as 8-8-8 or 13-13-13. That doesn’t seem quite right to me, based on what I’ve read for many years. But, then, I don’t always believe exactly what gardeners tell me about their fertilizing practices, just as I often suspect a fine cook might be fudging slightly when passing on an heirloom recipe.

Do you have to fertilize at all? Not always. I err seriously on the not-at-all side, especially with houseplants, since I’ve killed so many of them over the years with too much watering and fertilizing.

My husband, with the planter at Madison Central, generally over-fertilizes, by my yardstick of feeding. And both of us do fairly well. If you plant in good soil to start with (which means soil amendments, in our climate, and that’s what next week’s column will be all about), many plants do just fine. But I always wonder how much better they would do, with their preferred diet.

What form of fertilizer do you choose? There’s liquid and there’s granulated. The liquid is easy to mix and pour around each plant. It is especially nice for houseplants. Liquid fertilizing is absorbed quickly through roots and foliage. But it washes out with repeated watering or rainfall, and so needs replenishing regularly.

Granulated fertilizer is easier to broadcast on the soil, and you can choose the regular, for a fast fix, or the slow-release, or timed-release, for sustained feeding. But you have to be careful not to let the granules “burn” the leaves, so apply carefully and water in thoroughly, unless you can accurately predict coming rainfall.

Ever eat something, a soup or a sauce, prepared by a cook who thinks that if a pinch of something is good, a big dollop is better? Especially salt? (Of course I don’t think you can have too much pepper, but others might disagree.) The same thing applies to plants. Another big dose of plant food isn’t always the answer if a plant isn’t doing too well, just like watering more frequently might do more harm then good. If you’re in doubt, feed at half strength. I always suspect package directions of being too generous, because, after all, they want you to go back and buy more, pretty soon.

When should you fertilize? Now isn’t a bad general time, but the answer depends on the specific plant. With my daffodils, right now is the right time. With summer annuals, every two weeks during their growing season works well. And stop feeding most things, such as shrubs and perennials, by August, so they can harden growth for the coming winter.

A footnote: what about organic vs. inorganic? In the current “green” emphasis, it might seem a good thing to go organic? It feeds slowly, rarely burns a plant, and won’t kill the beneficial bacteria in the soil. But it’s often more expensive and relatively harder to find. The inorganic, or chemical, fertilizers give a quick feed and often are less expensive, but can destroy the good guys such as earthworms.

As with so many things about gardening, the answers may be different about fertilizing, just as feeding your family members isn’t generally a one-menu-fits-all project. Try something sparingly at first, take notes or at least pay close attention, and in a few seasons you will have a good feel for what works.