Organic Garden Helpers
Same biology, where you live — from my garden to yours.
I grow roses organically by active ingredient — the same biology whether you garden in Tbilisi or Texas. But the biopreparations on my shelf here in Georgia aren't the ones you can order, so I've gathered the products that carry the same active ingredients I rely on in the book, available to you on Amazon. Same biology, where you live.
New to this? Start with three
You don't need a shelf full of bottles. Begin here, and add the rest only as you meet a problem:
- Bacillus subtilis — your everyday shield against disease on the leaves.
- Beauveria bassiana — quiet prevention for the common pests.
- Seaweed & humates — feed the plant strong, so most trouble bounces off.
To stop & prevent disease
Black spot, powdery mildew, rust and the rest — handled by biology, not chemistry.
A friendly bacterium you spray on the leaves — it crowds out black spot, powdery mildew and rust before they take hold. It comes two ways: a concentrated powder you mix yourself, or a ready-to-use liquid.
How to use: Spray on dry foliage every 7–14 days through warm, wet weather and after rain. Mix with non-chlorinated water only.
A soil fungus that hunts the disease fungi where they overwinter — in the soil and the mulch, not on the leaf.
How to use: Drench onto moist soil and mulch. Don't tank-mix with Bacillus — use them on different days.
The classic that genuinely works on powdery mildew and rust — it shifts the pH on the leaf so the fungus can't cope. Also knocks back spider mites.
How to use: Dust or spray in the cool of the day, never in strong sun. Keep it well apart from oil sprays (two weeks either side).
Knocks back powdery mildew that's already started — and it's potassium bicarbonate, not ordinary baking soda (whose sodium builds up in the soil).
How to use: About 1 tbsp per 4 L of water with a drop of mild soap, undersides included.
To deal with pests — safely
Knock back the pest without wiping out the bees, ladybugs and lacewings doing your work for free.
An insect-killing fungus — my prevention for thrips, whitefly and mealybugs. It infects the pest, not the plant.
How to use: Spray onto the pests and the leaf undersides; repeat per the label. Keep it off open flowers.
A soil-dwelling fungus that breaks the overwintering cycle of sawflies, thrips and others. It harms only chitin-shelled pests.
How to use: Drench the ground around the bushes in autumn, and again in spring while the soil is warm.
Repels and limits a long list of pests and softens an outbreak.
How to use: Foliar only — never on open flowers where the bees are working.
A contact spray for soft-bodied pests — aphids, whitefly, young sawfly larvae.
How to use: Hit the pests directly, undersides included; repeat every 5–7 days.
A fine oil that smothers the pests and eggs waiting out the winter — scale, mites, aphid eggs — before they ever wake up. The quiet late-winter clean-up that saves you spraying all summer.
How to use: On a mild, frost-free day while the bush is still dormant. Never in heat or strong sun, and keep it two weeks apart from any sulphur.
Targets caterpillars only and spares bees and ladybugs — and it's useless on sawflies, so be sure which one you have.
How to use: Spray on the foliage the caterpillars are eating.
Monitor and thin whitefly and thrips before they build up — yellow for whitefly, blue or yellow for thrips.
How to use: Hang a few among the roses at bud height.
To feed & strengthen
Half of organic rose care isn't a spray at all — it's a plant too strong to get sick.
Kelp feeds trace elements and natural growth substances that help a rose build its own resilience — this is half of organic rose care. Two forms, same seaweed: a liquid concentrate and a dry meal.
How to use: Liquid as a foliar feed or soil drench through the season; the meal worked into the soil in spring as a slow release.
My own favourite feed — a fish-and-seaweed blend that pushes steady, healthy growth without forcing the soft, disease-prone shoots that a heavy chemical feed gives you.
How to use: Diluted as a drench or foliar feed every couple of weeks in the growing season. It smells of the sea for a day; the roses don't mind.
Humic and fulvic acids from ancient organic matter — they wake up the soil, unlock nutrients that are already there and help the roots take them up. Comes as a liquid or dry granules.
How to use: Liquid drench for a quick lift; dry granules worked in for the long game.
Switches on the plant's own defences before trouble starts — a quiet, powerful bit of prevention.
How to use: Spray as a preventive through the growing season.
Gentle living fertiliser and a dose of beneficial microbes in one — it feeds lightly and never burns, even on young plants.
How to use: A couple of handfuls worked into the planting hole, or top-dressed around the base and watered in.
Root-partner fungi that extend a rose's reach for water and phosphorus many times over and make the whole plant tougher. They only work in direct contact with the roots.
How to use: Dust or mix onto the roots at planting or transplanting. It's a planting-day friend — established plants gain far less.
A living mix of lactic-acid bacteria, yeasts and others that tips the soil toward life and away from rot.
How to use: Diluted and watered into the soil, or added to the compost and mulch to speed it along.
Biochar gives soil microbes a honeycomb to live in; inoculated, it arrives already full of them. It holds water and nutrients right where the roots can reach.
How to use: Work it into the soil at planting, or top-dress and water in. A one-time, long-lasting improvement.
For when you'd rather not juggle bottles: mycorrhizae, Trichoderma and beneficial bacteria in a single water-soluble scoop — the soil-life starter kit in one.
How to use: Dissolve and drench onto moist soil, or dip the roots at planting.
The trace elements — iron, zinc, manganese and the rest — that roses need in tiny amounts but sulk without. The fix for stubborn yellowing when the main nutrients are already fine.
How to use: As a foliar feed or soil drench when leaves pale between green veins; a little goes a long way.
A fast, soluble organic feed with a little seaweed and microbes in the mix — handy for a quick pick-me-up in pots or beds.
How to use: Dissolve in water and feed every couple of weeks in the growing season.
The steady main meal of the season — a gentle granular feed that won't scorch and builds the soil as much as the plant.
How to use: Worked into the soil around the base in spring and again mid-season, then watered in.
Tools worth having
Your best tool against canker, dieback and stem borers — a clean cut into healthy wood stops them cold, no copper needed.
How to use: Disinfect the blades between cuts (alcohol or a bleach wipe); cut to an outward bud, leave no stub.
And two from your kitchen — free
Milk whey or kefir — one litre to ten litres of water, sprayed on the leaves, keeps black spot down.
Garlic infusion — a simple home-made repellent for aphids, beetles and egg-laying sawflies.
Not sure what's actually wrong with your rose?
My guide walks you through it, problem by problem — with a photo for every one.
A few honest answers
Do I really need all of this?
No. Start with the three above and add the rest only when you meet the problem it solves. Most gardens never need the whole list.
Are these safe around bees and pets?
Used as described, yes — keep sprays off open flowers, treat in the cool of the day, and the biologicals here target pests and fungi, not your bees or earthworms.
Will it work in my climate?
The biology is the same everywhere; you just adjust the timing to your own season. The book's "golden rules" and the per-problem schedules take care of that.
Come and grow with us: free articles here on the blog, and our Rose Gardening community of almost 72,000 gardeners from all over the world.