Pond & Aquatic Weed Control in Central PA

Lawns Plants & Pests LLC provides licensed aquatic vegetation management for ponds, farm ponds, lakes, water features, and constructed wetlands throughout Dauphin, Cumberland, Lebanon, and surrounding Pennsylvania counties. Algae control, aquatic weed treatments, mosquito larvae management for standing water, and seasonal pond management programs. We're certified for aquatic herbicide application and we follow Pennsylvania Department of Environmental Protection and EPA regulations on every job. Free estimates. Call or text 717-379-3248.

Aquatic herbicide applications aren't the same as land-based pesticide work. Different products, different label restrictions, different applicator certifications, and additional permitting requirements depending on the water body and what's downstream. Hiring an unlicensed applicator to spray Roundup or copper sulfate into a pond can result in fish kills, regulatory violations, and contamination of nearby waterways. We're licensed for aquatic applications and we know when a job needs a permit and when it doesn't.

Our Aquatic Services

Algae Control

Filamentous algae (the green "pond scum" that floats on the surface), planktonic algae (turns water green), and chara (looks like underwater plants but is actually algae) are the most common pond complaints. We identify the type, treat with the appropriate aquatic algaecide at the right water temperature, and recommend long-term management — most algae problems are nutrient-driven and recur unless the underlying nutrient load is addressed.

Aquatic Weed Control

Submerged weeds (pondweed, coontail, milfoil), floating weeds (duckweed, watermeal, water lilies that have taken over), and emergent weeds (cattails, rushes, sedges) all need different products and timing. We identify the species before treating — the wrong herbicide on the wrong weed wastes money and risks fish habitat. For invasive species (Eurasian watermilfoil, hydrilla, parrotfeather), proper identification and treatment is critical because partial treatment can spread the infestation.

Mosquito Larvae Treatment for Standing Water

Ponds, ditches, livestock troughs, and other standing water are major mosquito breeding sources. We apply larvicides — Bti (Bacillus thuringiensis israelensis) and methoprene — that kill mosquito larvae but are safe for fish, frogs, birds, dragonflies, and other beneficial aquatic life. This is the gold standard for mosquito source reduction on rural properties and farms.

Pond Vegetation Management Plans

For larger ponds, recurring problems, or properties where the pond is a featured asset, we build seasonal management plans. Spring algae prevention, summer weed control, fall preparation, and ongoing monitoring. Most pond problems are easier to prevent than to fix once they're severe.

Pond Restoration Consulting

Severely overgrown or stagnant ponds usually have multiple compounding issues — nutrient overload, sediment buildup, fish die-off, invasive species, low dissolved oxygen. We assess the situation and lay out a realistic restoration plan, which may include treatments we provide, mechanical work (dredging, vegetation removal) you'd hire separately, and management changes to prevent recurrence.

Aquatic Treatment Permits

Most aquatic herbicide and pesticide applications in Pennsylvania require permitting through the PA Department of Environmental Protection (DEP), and some applications also fall under EPA NPDES (National Pollutant Discharge Elimination System) requirements. Whether your pond needs a permit depends on size, whether it discharges to other waterways, and the specific products being used. We handle the permitting process for our clients when required, and we'll never apply restricted aquatic products without the appropriate authorization in place.

Service Area

We provide aquatic services throughout Dauphin, Cumberland, Lebanon, and York Counties — including Harrisburg, Paxtang, Penbrook, Steelton, Highspire, Middletown, Hummelstown, Hershey, Palmyra, Annville, Cleona, Lebanon, Grantville, Linglestown, Colonial Park, Susquehanna Township, Lower Paxton, Camp Hill, Mechanicsburg, Lemoyne, New Cumberland, Wormleysburg, Enola, Marysville, Halifax, Millersburg, Elizabethtown, Mount Joy, Mount Wolf, Manchester, Dillsburg, Carlisle, Boiling Springs, and surrounding Central Pennsylvania communities. . We work with residential ponds, farm ponds, golf course water features, HOA detention ponds, and private lakes.

Frequently Asked Questions

How much does pond treatment cost?

Pricing depends on pond size (surface acres), the type and severity of the problem, and whether permitting is required. Small backyard ponds are obviously much less than multi-acre farm ponds. We give free estimates after looking at the pond — many initial assessments can be done from clear photos.

Will treatments hurt my fish?

Used correctly, aquatic herbicides and algaecides are safe for fish at label rates. The biggest risk to fish from pond treatments isn't the chemical — it's oxygen depletion when large amounts of vegetation die and decompose at once. We treat in stages on heavily infested ponds to avoid oxygen crashes. We also avoid hot summer afternoons when dissolved oxygen is already low.

Can I treat my pond myself with stuff from Tractor Supply?

Some general-use pond products are legal for property owners to apply. Many of the more effective aquatic herbicides and algaecides are restricted-use and require licensed application. Beyond legal questions, identification matters — we see plenty of self-treated ponds where the wrong product was used on the wrong species. Money spent and the problem still there. If you're not sure, let us look first.

Do you also stock fish or do pond aeration?

No. We focus on vegetation and pest management. For fish stocking we'd refer you to a Pennsylvania-licensed fish supplier, and for aeration system installation we'd refer to a pond contractor. Both can dramatically improve pond health when paired with vegetation management.

When is the best time to treat a pond?

Most aquatic herbicides work best when water temperatures are above 60°F and plants are actively growing — generally May through September in Central PA. Algae often peaks in late spring through summer. Cattail and emergent weed control is most effective in mid to late summer when plants are translocating to roots. Each species has its own optimal window.

Do you treat invasive aquatic species?

Yes. We treat Eurasian watermilfoil, hydrilla, parrotfeather, and invasive duckweed/watermeal. Invasive aquatic plant management often requires multi-year programs because partial treatment can leave fragments that re-establish.

Get a Free Pond Estimate

Call or text 717-379-3248 or email Lawnsplantspests@gmail.com for a free pond or aquatic estimate. Licensed Pennsylvania aquatic applicator. Permits handled when required. Serving Central Pennsylvania.