Lawn fertilizer & weed control across the Bitterroot Valley

What does the Ravalli County Weed District actually publish?

A priority list of eight species it asks residents to report on sight: blueweed, common bugloss, orange hawkweed, salt cedar, Japanese knotweed, purple loosestrife, rush skeleton weed, and yellow flag iris. Alongside it the county publishes identification material covering Canada thistle, Dalmatian toadflax, houndstongue, oxeye daisy, sulfur cinquefoil, whitetop, and dyer's woad.

Spotted knapweed and leafy spurge sit on the Montana state noxious weed list and are familiar to anyone who has walked a valley fence line. "Noxious" here is a legal designation about the damage a species does, not a comment on how it looks. We have written up what that means for a landowner.

Where does weed pressure come from on a valley property?

Corridors and disturbance, almost always. Irrigation ditches, road frontage, driveways, fence lines, equipment tracks, and any boundary with untreated ground. Noxious species colonise disturbed soil before they move into intact cover, so the pattern of a property's weed problem usually follows its access routes rather than its lawn.

The useful consequence is that treatment can be targeted. Broadcasting product across acreage costs more, achieves less, and is the fastest route to resistance.

Does the treatment calendar change between the north and south ends?

The windows shift, the logic does not. MSU Extension's Montana guidance is 2 to 4 pounds of actual nitrogen per 1,000 square feet a year across two or three applications, timed roughly around Memorial Day, Labor Day, and after the final mowing about four weeks before the soil freezes.

That last window is defined by soil temperature rather than a calendar date, so it lands later at Florence than at Darby. We confirm it on the ground. And if only one or two applications are happening, the autumn ones are the ones that matter.

Do you take on acreage as well as lawns?

Yes, quoted as a separate scope from the lawn so you can see what each part costs. On most valley properties the mown lawn is the smaller problem and the ditch banks, edges, and un-irrigated ground are the reservoir feeding it.

Both halves are regulated work. We are certified and licensed for fertilizer, weed control, and pesticide application, which sets rates, buffer distances near water, and re-entry intervals by the product label rather than by preference — and near a ditch or the river those buffers are the binding constraint.

Where should a property owner start?

With identification, not with a product. Knowing whether you have ordinary broadleaf lawn weeds or one of the county's priority species changes everything that follows, including whether the right first call is to us or to the Weed District.

Send us photographs and the address and we will tell you what we think you are looking at. Estimates are free, they come back within 48 hours, and we cover the valley from Florence through Hamilton to Darby as well as the Missoula side. Get in touch.

What is the cheapest thing I can do myself?

Raise the mower. Cutting the common bluegrass, fescue and ryegrass mixes at 2.5 to 3 inches instead of scalping them gives deeper roots and fewer weed problems, and it costs nothing but a turn of the deck-height lever. Take about a third of the blade at a time and leave the clippings down — they return nitrogen and they are not what causes thatch.

Second cheapest: change how you water. Deep and infrequent, early in the morning, instead of a short daily cycle. Frequent light watering produces shallow roots and specifically favours annual bluegrass and rough stalk bluegrass, which are weeds you will then pay somebody to treat.

Between them those two changes fix a surprising proportion of the lawns we get called out to look at, and we will say so on the visit if that is what we find rather than quoting a programme you do not need.

More resources