I use Osmocote. Expensive, but it is a slow release and you don't need a lot.

Although technicaly not a fertilizer, my favorite is compost. Fully organic, good for improving the soil and all-around nutrient supplementation, an annual mulching with compost pretty much removes the need for any other fertilizers.

Calling out a "favorite" fertilizer is buying into the MiracleGro-must-have-fertilizer myth a bit too deeply. Plants that are established in the landscape typically do not need to be fertilized on any routine basis. Sometimes never. Excessive fertilization is more harmful than none at all and a huge pollutant from run-off. Generally the recommendation is not to fertilize unless/until a need is determined by stunted plant growth, lack of vigor or other obvious deficiencies. And then only after a soil test determines what nutrients are lacking. Most often lacking is nitrogen and the application of organic matter as a mulch - like compost - easily addresses that need.

Containers are another matter altogther. I use Osmocote when potting up and supplement with FoliagePro as needed.

Thanks, gardengal! I am just learning and I have so many questions.

Do you topdress your entire yard with compost every year? How deep of a layer do you have to put on?
Do you buy compost in bulk?

My containers do great but some of the plants in my yard seem to be kind of yellow instead of deep green and a little stunted. I am so curious how other people get nice healthy plants.

Depending on what plants you have growing in the yard they might need feeding plus moisture to thrive. I learned from garden writer, Ann Lovejoy to avoid beauty bark because it compacts and water doesn't get to plant roots. That might be what you have in your gardens. Use a garden fork or small trowel to poke in a bit & see what you have there.

She has articles online or her books available to learn about how she suggests to improve soil. She lives on Bainbridge Island now. Her writings inspired me to build lasagna style mounded beds right on top of our mossy grass with layers of organic matter when we were expanding gardens. Those beds stay moist & plants grow amazingly well. All we do is chop & drop (her term) when cutting plants back as well as top dress 2x a year (early spring when herbaceous plants are peeking out) & again in late fall after frost when you can get into the beds again) to keep the soil covered with 2-4" of mulch like frosting on a cake. Do not touch stems of plants with mulch. I've found it easiest to carry buckets of it into the garden & spread gently by hand. Alternatively, if my garden helpers dump it in small piles between plants I go through & spread carefully to not smother plants. It doesn't work to spread with a shovel or rake if you have closely planted beds.

Some plants don't like all that moist mulch like lavender, rosemary, thyme, Dianthus, and rock garden plants like sedums, so you can skip those areas or beds.

There is a dramatic difference between the lasagna made beds and the ones with our native rocky, clay soil even though we top dress them. Eventually, over time they have improved, but still they don't compare with the lasagna made beds. We're in the midst of a move, so I'll be building gardens again with the layers rather than digging in. I know it works!

We use our own compost (with manures), dried grass clippings, shredded leaves & used coffee grounds then top with either wood chips or bagged soil conditioner called PEP from Home Depot that decomposes by spring. Whatever you use on top is what people see, so you can put any compost ingredient on the soil. The bagged PEP is less expensive than compost & worked well in the fall over the rougher organic matter. I would purchase it again if I run short.

Use what you can gather up or make after you get growing awhile, but initially you may need to purchase. Buying compost in bulk is always less than the bags. If you have more than you can use save in garbage cans or plastic bags with small holes poked in for mid summer additions or to fill holes when transplanting. It's handy to have around.

The common chemical or organic fertilizers have 3 elements: N, P,k: P(phosphorus) sticks to soil and is not depleted as fast. K( potask) is semi stable and only some of it can be depleted by excess water. N(nitrogen) being soluble in water, drains fast. Also, plants are crazy about it and take as much of it as they can to the point of getting suffocated. THEREFORE, using the so-called all purpose fertilizer is not like ONE SIZE FITS ALL.
For an established garden for many years, probably it is rich in phosphorus and potasium. So then all you need is nitrogen once in a while, a little bit at a time. This is especially suitable for leafy veggies that you wouldn,'t want them to flower or bare fruits.

For the reasons above, I use very little of the ALL PURPOSE fertilizers early on and then switch to Nitrogen only , EXCEPT for bloomers and fruiter. I feed things like PARSLEY, BASILS, ALLIUMS, CILANTROS..ETC just nitrogen. The thing with nitrogen deficiency or excess of it can be observed in the plants: Pale green, yellowish foliage often indicate Nitrogen deficienc. VERY dark green color would tell me that Nitrogen is used too much. To cure this, you have to water the plants more often in order to wash out(detox) the plants.

Another thing: I don't practice ORGANIC religion when it comes to fertilizers. Althou I am all for compost, manures..(if I can get them free or a reasonable amount). But I would not pays arms and leg for ORGANIC fertilizerd nor I will pay double the cost for the so-called organic vegetables and fruits. I Think the issue of ORGANIC in gardening is just an environmental issue, which is comendable.

I'm really partial to top dressing perennials with compost during the late fall or winter. During the growing season, liquid fish fertilizer is one of my favorites. It really depends on what you are fertilizing. Bulbs like bone and blood meal after blooming. Alfalfa meal or alfalfa tea is great for extra nitrogen. Whatever you use, do so with care. More is not necessarily better.