I have a large and never-fed garden. I wish to start feeding these plants. I’m composting now, but when and how often do I fertilize?
Has your garden been thriving in years past? If so, I don’t think you need to add fertilizers. There’s no single packaged fertilizer that will be universally beneficial to every plant in your garden. Different plants have different needs, and it’s never wise to add fertilizer without doing a soil test.
On the other hand, you mention you are tending a compost pile. You can apply compost once or twice a year and it will be helpful to all your plants.
Here is information from The Ann Lovejoy Handbook of Northwest Gardening (Sasquatch Press, 2007):
“When do we need to feed? For ornamental plants, including trees and shrubs, spring and fall are the traditional feeding times. Spring feeds are generally fast-acting, offering rapidly growing plants the nutrients they need for a strong summer performance. A feeding mulch of compost can be fortified with fast-acting alfalfa, which will release more nitrogen if combined with composted manures. Alfalfa comes in meal or pellets. I like the big pellets used to feed goats, which are easy to spread and are available without added medication [my note: some alfalfa is treated, for use as animal feed].
“In fall, most plants stop producing fresh top growth, even though our Northwest winters are generally mild. Fall is a good time to feed roots, which continue to stretch and grow underground despite low temperatures. Adding whole fish meal to your compost feeding mulch will fortify roots with phosphorus.”
Professor Sarah Reichard, director of UW Botanic Gardens, discusses fertilizers as sources of pollution in our water supply. In her book The Conscientious Gardener: Cultivating a Garden Ethic (University of California Press, 2011), she states:
“If water inevitably drains downhill, how do we stop fertilizers and pesticides from moving with it? The easiest way is not to use them. This needn’t come at the cost of your plants. Most woody plants and herbaceous perennials do not require much fertilizer. Mulching with well-aged manure, compost, or other easily broken-down organic materials will supply all the necessary nutrients.”
Is it okay to fertilize my rhodies, azaleas, and roses in September? I missed
doing it in August.
Generally speaking, it is best not to fertilize your shrubs after mid-summer. The tender new growth that results is susceptible to frost, disease, and insects just at the time of year when the plant is beginning to shut
down. This is also true of roses, which are even more tender and susceptible than rhododendrons and azaleas.
An article by Terri Richmond (British Columbia) on the American Rhododendron Society website, entitled Fertilizing Rhododendrons the Organic Way supports the practice of fertilizing in spring. (Keep in mind that azaleas are in the same genus as rhododendrons.)
Oregon State University Extension suggests that budbreak in spring is a good time to fertilize roses, just as new growth is beginning. Stop fertilizing in late summer. Oregon State University also weighs in on fertilizing rhododendrons (if needed, in spring shortly after flowering, and preferably with organic fertilizer).
We have a white peach tree that was just OK this year. I am wondering what I can do to get the most out of it next year – what is the best fertilizer for peaches?
According to Sunset’s Western Garden Book of Edibles (2010), peach trees may be fertilized with a 10-10-10 complete fertilizer (the numbers correspond to N-P-K, nitrogen, phosphorus, potassium) at bud break in late March. “Give young trees 1/2 pound per year of age and give mature trees up to 5 pounds (for full-size, full-grown trees). Spread fertilizer evenly over the entire root zone.”
Washington State University Extension has general information on fertilizing for home orchardists. Here is a relevant excerpt:
“Nitrogen is not needed in most of western Washington since we have such high levels of organic matter in our soil, and it is continually released during the summers. Nitrogen controls growth. With excess we get rank growth. Fruit maturity is delayed; and storage life of apples and pears is reduced. Peaches need more nitrogen so applications may be necessary.”
Successful gardeners know that healthy soil translates to healthy plants. See the guide to soils and fertilizers for the home gardener from WSU Cooperative Extension.
Gardeners with a wood burning stove or fire place often wonder whether they can use the ash as a source of potassium. The answer is yes if only wood (and no glossy paper) was burned. Where and how much? That depends. Wood ash raises soil pH, so if you have acid soil use it on the vegetable garden where a neutral pH is preferred, but avoid shrubs that like acid soil, such as Rhododendrons and Camellias. Recommended amounts vary, from a cupful around rose bushes to 20 pounds per 100 square feet for slightly acidic soil. Always work it into the soil. Read more about wood ashes from Oregon State Extension