We have never used an insecticide, fungicide, herbicide or anything else ending in "cide," and we don't use synthetic fertilizer. We feed the soil instead: compost and bone meal with no nitrogen at planting, heavy wood mulch every year, and leaf feeding that stops in early August. The thinking comes from Elaine Ingham, Michael Phillips, John Kempf, Gary Zimmer and Christine Jones; the Montana numbers, from Montana State University.
Why we don't use anything ending in "cide"
Because reaching for the bottle stops you from asking why the problem showed up, as our About page says. The harm chemicals do to human and ecological health is real, but we think the worst of it is what they do to the grower: stop asking why a disease entered the system, and how you helped it in, and you stop learning. In our words, "The insights we have gained by asking ourselves how we contributed to a certain infestation have prevented us from dealing with future ones."
The soil science points the same way. Elaine Ingham, the soil microbiologist who wrote the first six chapters of the USDA's Soil Biology Primer, said in 2003: "Every pesticide kills something beneficial in the soil. High rates of fertilizers kill beneficial soil life, too, through simple osmotic shock." Michael Phillips, who grew apples in northern New Hampshire and wrote The Holistic Orchard, built his program on competitive colonization, crowding bark and leaves with beneficial microbes so disease has less room. He warned that even the mineral fungicides organic growers use "will compromise arboreal colonization." Ingham died in 2026 and Phillips in 2022. We still lean on both.
What a fruit tree wants underground
A fungal soil. Ingham's Soil Biology Primer puts productive farm soils near a 1:1 ratio of fungal to bacterial biomass and deciduous forests at 5:1 to 10:1, and the notes to her 2019 interview with Joe Lamp'l put a healthy orchard at about ten times more fungi than bacteria. Those ratios are argued over (a 2019 review of 192 studies found they swing with the lab method), so we read them as a direction, not a target. Untilled ground under woody plants trends fungal, and that's what we're building.
Christine Jones, the Australian soil ecologist, explains why. Mycorrhizal fungi "acquire their energy in a liquid form, as soluble carbon directly from actively growing plants," and she writes that they "can supply up to 90% of plants N and P requirements." She calls it the liquid carbon pathway. The catch: "If plants can obtain nitrogen or phosphorus easily, they will stop pumping carbon into the soil to support their microbial partners." Soluble fertilizer doesn't just feed the tree. It lays off the tree's partners.
Phillips said it shorter: "Our goal, plain and simple, is fungal duff."
What we do at planting
Feed the soil and leave the tree alone: no nitrogen in the hole, for any plant. From our planting guide:
- Soak the roots 2 to 24 hours, no longer.
- Dig about 1.5 times the root spread and roughen the hole's walls so roots can get through.
- Backfill with about a third compost to native soil, plus bone meal (or whole bones, which break down slower).
- Plant at nursery depth and mulch heavily, hardwood if you can get it.
Skipping nitrogen is Jones's pathway in practice: a tree handed easy nitrogen stops paying its fungi. The bone meal is for phosphorus, which our friend Bob Purvis of Homedale, Idaho, says helps mainly at planting and has to be worked in.
Gary Zimmer, the Wisconsin biological farmer, likes strip tillage because it's "like putting a flowerpot under every plant." In an orchard, disturb the hole and its strip and leave the rest alone. Purposeful tillage is one of his six rules of biological farming. The others: test and balance the soil, use the gentlest fertilizers, keep pesticides, herbicides and nitrogen to a minimum (we go to zero on the first two), plant for diversity, and feed soil life carbon and calcium.
Mulch and compost every year
The yearly job is keeping wood on the ground. Our planting guide calls for "copious amounts of mulch," hardwood by preference. Phillips wanted ramial chipped wood, meaning chipped twigs and branches under about 2 3/4 inches thick, because "the soluble lignins in ramial wood chips fuel the biology to produce the best type of organic matter." He spread it 2 to 8 inches deep and uneven on purpose: a ring around young trees, then thick piles on a different side of each bearing tree from year to year.
Keep mulch about 6 inches back from the trunk (University of Minnesota Extension), since voles nest in it under the snow and chew bark. And don't till under the trees. Phillips: "Excessive or deep tillage breaks up the fungal network of mycelium."
Compost goes on in spring, because we don't feed through the roots into July, and it has to be real compost. Ingham: "Compost is not made by throwing a bunch of organic matter together in a pile and leaving it for a while."
What to feed through the leaves, and when
Feed through the leaves until early August, and stop feeding through the roots before July. Both cutoffs, from our planting guide, are about winter: late feeding keeps a tree growing when it should be shutting down.
For what to spray, Phillips's four spring "holistic" sprays make a good cold-country model. His 4-gallon backpack mix was 10 ounces of liquid fish, 6 ounces of effective microbes (EM), a dollop of blackstrap molasses, half an ounce of dry seaweed extract and 2.5 ounces of pure neem oil. Neem is technically a pesticide (the National Pesticide Information Center calls it "a naturally occurring pesticide"), and we don't use cides, so leave it out. The fish, kelp and microbes are the nutrition-and-biology part.
| When | What goes in the sprayer | Why |
|---|---|---|
| Quarter-inch green | fish, kelp, EM, molasses | Phillips's "catalyst" spray; wet the trunk and mulch too |
| Early pink | the same | microbe cover on leaves and flower clusters |
| Mid-bloom (optional) | EM, kelp, molasses | no fish on open blossoms |
| Petal fall | fish, kelp, EM, molasses, to runoff | lots of new leaf and fruitlet to cover |
| 7 to 10 days later | the same | Phillips's "first cover" |
| Summer to early August | no fish; add fermented comfrey tea | his "homegrown source for bioavailable calcium" |
Ingham's aerated compost tea also goes on the leaves, brewed about 24 hours at 70F or warmer. Treat it as a biology booster, not a cure: Linda Chalker-Scott of Washington State University found aerated teas "have no scientifically documented effect as pathogen suppressors."
What we don't do: nitrogen in the hole, soluble synthetic fertilizer, neem, root feeding into July, or leaf feeding after early August.
Understory and diversity
Grow something between the trees, and as many kinds as you can. Jones's first principle is that green is good and year-long green is better, since only growing plants feed mycorrhizal fungi. In the Jena Biodiversity Experiment she cites, soil under at least four plant families came out "significantly deeper and better-structured." Phillips called a diverse understory "the principal means of replenishing organic matter from one growing season to the next" and valued tap-rooted herbs like comfrey for pulling minerals up from the subsoil. Our comfrey is the Russian type and hasn't spread much for us; chop and drop it around the trees. For nitrogen, Siberian peashrub, sea buckthorn and buffaloberry all fix it, and we rate all three to zone 2.
Young trees need a clear, mulched circle 3 to 4 feet across for their first 3 to 5 years, because weeds are "first in line for water and nutrients" (Purvis). Phillips left one "chicken tree" unsprayed so curculios gathered where his hens worked (he sprayed kaolin clay on the rest, which we don't use), and in an Oregon State trial, broilers ate nearly 99 percent of the codling moth and apple maggot larvae and pupae offered.
How to read a struggling tree
Ask why first, and look at water and nutrition before you blame a bug. For nutrition we use John Kempf's Plant Health Pyramid as a checklist. Kempf, an Amish grower from northeast Ohio, founded Advancing Eco Agriculture (AEA) in 2006 after his family's farm had heavy pest and disease losses while relying on pesticides. The four levels:
| Level | What it takes, per AEA | What AEA says the plant then resists |
|---|---|---|
| 1. Complete photosynthesis | magnesium, nitrogen, iron, manganese, phosphorus | soil-borne fungi such as verticillium, fusarium and phytophthora |
| 2. Complete proteins | magnesium, sulfur, molybdenum, boron | sucking and larval insects, aphids and thrips included |
| 3. Lipid synthesis | most of its nutrition coming from soil microbes | powdery mildew, fire blight, rust |
| 4. Secondary metabolites | a diverse, abundant microbiome above and below ground | chewing insects, beetles included |
Two cautions. It's AEA's model, AEA sells the tests and products that go with it (some with synthetic nitrogen we'd never use), and we haven't found a peer-reviewed trial of it. And some pests hit well-fed trees anyway, so don't count on feeding alone to keep codling moth out of your apples.
Where Kempf and the extension services agree is nitrogen: too much feeds aphids and fire blight and pushes late growth (Idaho, Minnesota and Maine extension), and manure counts. Purvis's yardstick for apples is 16 to 24 inches of new growth a year before they bear and 12 to 15 after. More than that, ease off. Less, check your watering first.
What we would test
Soil every two or three years, leaves in late summer, and sap only to watch a trend.
| Test | When | What it tells you | Watch out for |
|---|---|---|---|
| Soil | every 2 to 3 years (MSU) | pH, organic matter, every mineral including trace ones | switching labs; Zimmer sticks with one |
| Leaf tissue | mid-July to mid-August (WSU), or late July to early August after terminal buds set (MSU) | what the tree actually took up | sample leaves from mid-shoot |
| Sap | through the season (AEA) | trends in real time | readings shift with light, heat, hour and water, so compare the same trees at the same hour |
For a soil sample, Purvis takes 7 to 9 cores across the planting area, a foot deep or two if he can, mixes them in a 5-gallon bucket and sends a pint to the lab. Zimmer says to test trace minerals, not just N, P and K, and to take an excess as seriously as a shortage. For apple leaves, MSU's optimums are 2.0 to 2.6 percent nitrogen, 1.1 to 1.6 percent calcium and 25 to 50 ppm boron.
Ingham herself was "never one for soil testing," per The Orchard Project's tribute; she looked at the biology instead.
The minerals that keep coming up short in Montana
Boron, calcium and zinc, in a 2021 survey of 23 Montana orchards by MSU's Western Agricultural Research Center in Corvallis:
| Mineral | MSU 2021 survey | Why it runs short here | What we'd do |
|---|---|---|---|
| Boron | 84% of orchards low in the soil; 47% of leaf samples short | less available in alkaline soil, and it rides up the tree with water | test first, then a small foliar dose at bloom (WSU) |
| Calcium | 73% of orchards had deficient leaf samples | plenty in the ground, but it moves with water and loses out to fast shoots | steady water, moderate growth and crop |
| Zinc | 65% of leaf samples low | tied up in calcareous soil, and by too much phosphorus (Purvis) | test, and watch for slow bud break |
Calcium is the odd one, since our dry, calcareous dirt is full of it. Zimmer: "calcium is the trucker of all minerals and boron is the steering wheel." It goes where water takes it, and Purvis notes that in drought, water "leaves the apples with calcium to maintain turgor in the shoot tips and leaves, but it doesn't return later." So the fix is water and vigor, not more calcium. WSU's Bernardita Sallato found preventive calcium sprays didn't significantly cut bitter pit in a one-year Honeycrisp trial.
Boron's window is narrow (WSU calls midsummer leaves deficient under 20 ppm and excessive over 80), so add it only on a test result. Purvis's fix for pears is a tablespoon of borax in a gallon of lukewarm water before bloom. And apricots are easy keepers here: Purvis says they handle calcareous soil far better than apples, pears, peaches or sweet cherries and scavenge boron well.
Related guides
- Water for young trees in dry country
- The orchard as a system
- What to do when your bare-root trees arrive
Where this comes from
- Our About page, planting guide, rootstocks page and product notes.
- Elaine Ingham: USDA-NRCS Soil Biology Primer; Acres U.S.A. (2003); interviews with Joe Lamp'l (2019).
- Michael Phillips: The Holistic Orchard and his Practical Orchard Health handout (2014).
- John Kempf and Advancing Eco Agriculture, the Plant Health Pyramid; Gary Zimmer and Leilani Zimmer-Durand, Advancing Biological Farming.
- Christine Jones: "The Liquid Carbon Pathway" (2008), "SOS: Save Our Soils" (2015), Light Farming (2018).
- Bob Purvis's lecture notes on home fruit growing and on apricots.
- Montana State University (Western Agricultural Research Center and Extension).
- Extension at Washington State, Minnesota, Idaho, Maine and Oregon State; the National Pesticide Information Center; Wang and colleagues (2019), Acta Oecologica.
Updated September 2026.