BRAND · THE IPM SHELF
A contact spray only works where it touches.
Lost Coast Plant Therapy is the first bottle a lot of growers reach for when mites, aphids or mildew show up, and it sits on our IPM shelf as a concentrate and a ready-to-use spray. It works by contact, so how you spray matters as much as what you spray. Here is how to use it well.
How we stock it at Green Zone
Lost Coast Plant Therapy is on the pest and plant protection shelf, in concentrate bottles and a ready-to-use spray. The concentrate goes further: Lost Coast says 12 oz makes 12 gallons of spray.
It's a good first answer for houseplants, vegetables and tent plants alike. Lost Coast says it can go on anything from orchids to lettuce. When the trouble is a pest it doesn't list, our pest plan page has the other bottles on the same shelf: Pest plan: what we reach for first.
How it works, in one paragraph
Lost Coast calls it a 3-in-1 insecticide, fungicide and miticide, made as a minimum risk pesticide, the EPA's category for products made only from a short list of low-risk ingredients. Soy oil coats soft-bodied pests and smothers them on contact, peppermint oil repels, and citric acid makes the leaf surface a poor home for powdery mildew. The catch is in the word contact. It has no effect on hard-shelled insects, and it can't stop new pests from arriving, so it works best sprayed thoroughly and on a schedule.
The lineup
Lost Coast Plant Therapy concentrate
Mix 1 oz per gallon of water, the same rate for a foliar spray or a soil drench. Lost Coast lists soft-bodied insects, their larvae and eggs, plus powdery mildew, mold, rust and fungus. It can be used at any stage up to the day of harvest.
Where it fits: Spray or soil drench, any stage
Lost Coast Plant Therapy ready-to-use
The same formula, already mixed in a spray bottle, for when you only have a few plants to cover. Shake it well before and during spraying, because the formula separates.
Where it fits: A few houseplants or a small tent
Mixed spray keeps up to a week and a half in a sealed container, and the concentrate keeps for four years stored cool and dark with the lid tight.
Timing that keeps leaves from burning
Spray at 80°F or cooler, in low light: early morning or evening, never midday under the lamps. Lost Coast suggests watering the day before, and never drenching soil that has gone bone dry: water first, then drench.
Mildew is a humidity problem first. Spraying knocks it back, but if the room sits in the high 60s or above for hours, fix the air too. Our humidity answer walks through it: What humidity should I run, and what if I can't hit it?.
How it fits your grow, in 3 steps
Step 1. Test one plant first.
Lost Coast says to try any new method or amount on a single plant before the rest. Give it a day and look at the leaves.
Step 2. Soak every surface.
Undersides of leaves, stems and the top of the soil. It only works where it touches, so take your time and saturate the plant.
Step 3. Stay on a schedule.
For prevention, Lost Coast suggests once a week or two to three times a month. For a heavy outbreak, every day for 3 to 5 days, depending on the pest's life cycle.
Who it's for, and who it's not for
A good fit if
You've spotted mites, aphids, thrips, whiteflies or mealybugs and want to start gentle.
You see powdery mildew on leaves and want a spray you can use up to harvest.
You grow food or houseplants and want a minimum risk product.
Not the right fit if
The pest has a hard shell, like beetles or scale: Lost Coast says it generally has no effect on those.
You want one spray to keep pests away for a month: it works on contact, not as a shield.
Common mistakes we help people avoid
Spraying under hot lights. Above 80°F or in bright light, even plain water can burn leaves. Early or late, lights low.
Misting the tops only. Mites live under the leaf. Saturate the undersides.
Spraying without shaking. The formula separates, and an unshaken bottle sprays one ingredient too strong.
One spray and done. Eggs hatch after the first pass. Keep to the schedule until new damage stops.
Frequently asked questions
Can I use Lost Coast while plants are flowering?
Yes. Lost Coast says it can be used at any stage up to the day of harvest. Spray early or late, and avoid soaking open flowers more than you need to.
How much concentrate per gallon?
1 oz per gallon of water, for spraying or for a soil drench.
Does it work on fungus gnats?
It can go on as a soil drench at the same 1 oz per gallon, which is how you reach larvae in the soil. Let the top of the mix dry between waterings too. Our pest plan page has the full gnat routine: Pest plan: what we reach for first.
Is it the same as the pest plan page?
The pest plan page compares ten brands on our IPM shelf. This page is just Lost Coast, and how to get the most out of it. Call (508) 459-9609 to check sizes before you drive.
Keep going
Departments: Pest & plant protection · Houseplants
Grower answers: What humidity should I run, and what if I can't hit it? · Yellow leaves: is it a deficiency, and is this too much?
More deep dives: Pest plan: what we reach for first · Tent airflow · Athena
Want the short version of how we keep a grow steady? Get the free Stability Playbook
Before you drive
On the pest and plant protection shelf: Lost Coast Plant Therapy concentrate and ready-to-use spray.
Bring a photo of the pest or the damage, close up and under a leaf if you can.
Need one exact size? Call (508) 459-9609 first.
Photographed in the store on October 9, 2026.