Let OHP help build your herbicide rotation plan.

September 23, 2020

OHP's Herbicide Rotation Program 2020

A quality pre-emergent herbicide works to prevent weeds from germinating. Choosing the correct product(s) and using them properly is not so simple. Herbicide performance is a matter of application rate, environmental conditions, watering practices, and frequency of use.

Overuse of a particular herbicide may set the stage for herbicide resistance. Herbicide rotation is critical in getting the most out of a weed control program.

It is important to rotate MOA (Mode of Action) with herbicides just as with insecticides. Rotating MOAs will help prevent the creation of dominant weed species based on its tolerance to particular MOAs.

OHP has developed a wide range of granular herbicides designed to meet different grower needs, seasons, and crops. OHP herbicides are formulated on a uniform and dustless granule. These unique premium formulations increase delivery accuracy, and provide cleaner conditions for applicators and excellent plant tolerance.


Biathlon Herbicide from OHP, Inc.Fortress Herbicide from OHP, Inc.Fuerte Herbicide from OHP, Inc.

For more information on herbicide rotation, weed identification and control, contact your Regional Technical Sales Manager.


OHP adds Grotto Fungicide to biosolutions portfolio

April 20, 2020

OHP, Inc., announces the addition of Grotto™ Fungicide/Bactericide to its leading stable of pest control solutions for theGrotto Organic Fungicide/Bactericide ornamental industry.

Available immediately, Grotto is a high-quality copper octanoate, broad-spectrum fungicide that has activity on many greenhouse and nursery fungal and bacterial diseases.

Labeled for use on ornamentals plus vegetables and herbs grown in greenhouses, shadehouses, and nurseries. Grotto has a 4-hour Restricted Entry Interval (REI), Caution signal word, and OMRI (Organic Materials Review Institute) listing.

Grotto fits well in our biosolutions® segment and fulfills a grower’s need for shorter REI products and broadly-labeled products,” says Dan Stahl, OHP vice president and general manager. “Growers are demanding more products with 4-hour REIs.

Grotto is labelled for control of several challenging fungal and bacterial diseases such as bacterial leaf spot and blight, botrytis, downy mildew, fire blight, fungal leaf spot, powdery mildew, and rhizoctonia, on many ornamentals.

With Grotto and Kalmor® Fungicide/Bactericide in our biosolutions product portfolio, we now offer a broad range of copper-based solutions for our grower customers,” says Stahl.

OHP is a leading supplier of pest control solutions to the greenhouse and nursery markets.


How do I slow plant growth?

March 27, 2020

Growers have asked, “What can be done to slow growth on crops during times of low demand? “ —A great question. Let’s look at the available options.


If you find your crops growing under lower light levels, warm temperatures and heavy fertilization, excessive growth or stretching can occur. Excess growth can be slowed by growing crops cooler with increased spacing and using less water, a term called growing “harder.” If space allows, increase plant spacing and if crops can take colder temperatures in the 60º F range, you may want to consider this approach. The use of negative DIF (difference between daytime and nite time temp.) is also a growing technique useful during finish and can help reduce plant height.

OHP Plant Growth Regulators (PGRs)

Chemical plant growth control is a standard tool for growing many crops and is used during early plug, liner, and early to mid-finish production. Late application of PGRs to plants can offer growth control for a short period of time or stop growth in order to hold a crop for a long time. Such applications are done with a drench of triazole-based PGRs such as OHP’s Pac O. Below are suggested OHP products and rates that can offer late growth control.

B-Nine® WDG

A spray application at 2500 to 3750 PPM (mums) or 5000 PPM can offer growth control on a number of plants. Zinnia, coleus, mums and other large leafed plants respond well from B-Nine WDG foliar applications. Apply early in the morning and do not overhead water for 24 hrs. The lower rate of 2500 PPM is less risky but users may need to make a couple of applications. A tank-mix of B-Nine WDG at 1250 or 2500 PPM plus Cycocel at 1000 PPM will increase effectiveness. DO NOT use Cycocel rates over 1200 PPM.


We do not recommend the use of Cycocel in late finish as the rates needed for growth control may produce a yellowing. Cycocel is best used early to mid-cycle in crop production.

Pac O™ (Spray applications)

Foliar applications can vary wildly depending on the crops involved. Remember that viola, geranium, and begonia are VERY sensitive to Pac O. Sprays could range from 2 to 5 PPM. For other herbaceous crops use the mid to higher rate recommendations making sure to cover stems as best as possible; consider rates of 15 to 30 PPM. If crops have more leaves than stems showing you should consider B-Nine WDG sprays.

Pac O™ (Drench applications)

Drench applications are very effective in holding crops over. Consider using from 1 to 4 PPM using the correct drench volume for the pot size. A 1 PPM drench is like a 10 PPM spray. This 10:1 ratio can help you to determine what drench rate to use. Petunia baskets that are up to size will hold well using a 4 PPM drench.

Woody ornamentals are probably best held in check by using high spray rates or moderate drench rates of Pac O. Plants like azalea and other woody plants would use 100 to 150 PPM as a spray or 10 to 15 PPM as a drench. Lantana or other smaller plants respond well to a 2 PPM drench.

Generally speaking, one drench application should hold for 4 weeks or possibly longer. Drench volume is very important and users should follow the container drench volume rates in the label.


OHP Fortress herbicide – Now registered in California!

January 28, 2020

OHP, Inc. is pleased to announce the California state registration of Fortress® Ornamental Herbicide.Fortress ornamental herbicide used outdoor to control crabgrass, eclipta, bittercress, oxalis, marestail, spurge, purslane, and others

Fortress is now available for sale through authorized OHP distributors in California as well as in other states.

Fortress is a unique combination of the active ingredients isoxaben and dithiopyr formulated on a user-friendly engineered granule that provides virtually no dust and low odor. Personal Protective Equipment (PPE) requirements are minimal for the applicator.

The Fortress granules are uniformly round and do not hang up in crop canopy, resulting in better coverage and performance.

The specimen label lists many desirable perenn0ials, ornamental grasses, and woody plants that are tolerant to Fortress. Among the troublesome broadleaf and grassy weeds controlled by Fortress are crabgrass, eclipta, bittercress, oxalis, marestail, spurge, purslane, and others.

OHP is a leading provider of pest control solutions to the production ornamental and horticultural markets.

Click here for current state registrations, label, SDS and product information.


EPA approves 10 pesticides for use on hemp

January 2, 2020

In December of 2019 EPA (Environmental Protection Agency) approved adding hemp to the use sites of 10 pesticides. Nine of the products are biopesticides and one is a conventional pesticide. For further information, or to see the current EPA hemp registration applications, click here.

Below is a list of OHP’s current biosolutions offerings: