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Princep Liquid Herbicide works as a pre-emergent herbicide used to prevent a variety of grass and broadleaf weeds such as crabgrass, groundsel, goosegrass, and many more (see label for complete details). Use Princep Liquid Herbicide before weeds emerge or after already emerged weeds have been removed. With a variety of use sites Princep Liquid Herbicide is a versatile product that can be used on commercial and residential turf (Warm Season grasses only), nurseries, Christmas trees, shelter belts, and sod farms (only in Florida).
Note: Due to New California State restrictions, this Can Not be Sold in California.
DO NOT USE THIS PRODUCT ON COOL SEASON TURF OR INJURY CAN OCCUR.
Product Documents
| Active Ingredient | Simazine 41.9% |
|---|---|
| Target pests |
A wide variety of annual broadleaf and grass weeds, including crabgrass, goosegrass and groundsel and many others * See label for complete list |
| For use in |
Golf courses, residential and commercial lawns (Warm Season grasses only), nurseries, commercial landscapes and ornamental plantings (when tank mixed only), Christmas tree plantings, sod farms (Florida only), and shelter belts * See label for complete list and instructions |
| Application | * See label for complete application instructions |
| Pet safe | Yes, if used as directed on Label |
| Formulation |
Professional Product Group 5 Herbicide |
| NOT FOR SALE TO |
AK, DC CA, NY, VT (Restricted To Licensed Applicators Only) |
| Shipping Weight | 24.74 lbs |
| Manufacturer | Syngenta (Mfg. Number: 59200) |
| EPA Registration | 100-526 |
When tank mixing or sequentially applying simazine or products containing simazine, the total pounds of simazine applied must not exceed the specific maximum rate per calendar year as noted in the use directions.
Apply Princep Liquid before weeds emerge or after removal of weed growth. Princep Liquid controls a wide variety of annual broadleaf and grass weeds when used at selective rates in turf and ornamental plantings.
Where a range of application rates is given, use the low rate on coarse-textured soil and soil lower in organic matter; use the high rate on fine-textured soil and soil higher in organic matter.
Since Princep Liquid enters weeds mainly through their roots, moisture is needed to move it into the root zone. Very dry soil conditions following application may necessitate shallow cultivation or rotary hoeing.
WARNING: This product can expose you to chemicals including simazine, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to https://www.P65Warnings.ca.gov
Very Effective
By Tom on 08/21/2015
I have used Princep in every form available for over 25 years because it works and the product I bought here is equally effective. Great for parking lot cracks, fence lines and areas where no growth is wanted. Using the highest labeled rate works fine in these places.
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27 of 30 people found this review helpful
Princep
By Paul on 11/15/2014
Verified Purchase
Princep Post emergent Qualities
By Bill on 12/09/2019
Put down Princep about 3 weeks ago and have had surprisingly good results with post ermget knock down of annual bluegrass as well as some clovers and Parsley - Piert. Will do a follow up at the start of spring for full performance.
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9 of 10 people found this review helpful
Princep Liquid
By Frank on 01/25/2015
Verified Purchase
FOLLOW INSTRUCTIONS! It will work as claimed
By Cobia on 07/14/2022
I think most people who don't think it works do not follow the instructions. Three things MUST be done for successful results. 1. Application rate designed for square footage (area) of treated areas. 2. TIME OF APPLICATION! Most important. Do not expect this product to work after you have a forest of weeds growing in your driveway. This product is designed to PREVENT emergence of broad leaf, and with higher concentrations upon application, most any kind of plant you don't want growing in your parking lot, driveway, rock garden etc. etc. 3. Also VERY important. You have to apply this product, at proper concentrations, at the proper time of year, and make sure you also have at least 1/4" - 1/2" rainfall in the next two or three days, and if not, water it yourself. Read and follow instructions..... I love this product, but I know how much, what time of year, and how to "put it to bed" properly after I followed 1 & 2 above.
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6 of 6 people found this review helpful
You will need to use 0.75-1.5 fl. oz./1,000 sq. ft depending on your target weed. Most folks use the higher usage rate.
The first thing you need to know when using an herbicide such as Princep Herbicide is that the exact amount of water you dilute it with is not important. It is only important to make sure you are using the correct amount of product per 1,000 sq ft of lawn. Use too much and you risk damaging your lawn, use too little and you will not get adequate results. You will need to use 0.75-1.5 fl. oz per 1,000 sq ft . To decide how much water you want to use, you should mark a 1,000 sq ft area, fill your sprayer with WATER ONLY, and start walking and spraying just as if you were doing the actual application of herbicide. When you are done walking and spraying the 1,000 sq ft area note how much water it took you to spray that area, and that is the amount you will want to mix 0.75-1.5 fl. oz of product with for each 1,000 sq ft area that needs to be treated.
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120 of 151 people found this answer helpful
I live in Long Island, NY.
According to the product label, the manufacturer does not recommend folks use Princep Herbicide on Zoysia that far north. If you are looking for a pre-emergent for broadleaf weeds that can be used on Zoysiagrass, Surflan Pro would be an excellent option.
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0 of 1 people found this answer helpful
One 2.5 gallon jug of Princep Liquid Herbicide can cover 5-10 acres depending on the usage (1-2 qt per acre) rate needed for your use.
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78 of 87 people found this answer helpful
It was applied to an area last spring and would like to place a few plants in the same area.
I followed the 1 oz per 1000 sq feet and it did not touch the weeds in my yard.
Princep Liquid Herbicide is a pre-emergent weed control product and it will not control the weeds that have already emerged in your yard. According to the Princep product label: Apply Princep Liquid after September 1 (after October 1 for annual bluegrass) before emergence of winter annual weeds. Fall applications of Princep Liquid will control annual bluegrass, burclover, lawn burweed, common and mouseear chickweed, corn speedwell, henbit, hop clover, spurweed, and parsley-piert. Princep Liquid will also control these weeds soon after emergence. For control of summer annual weeds listed in the Product Information section of this label, apply Princep Liquid in late winter before the weeds emerge. Apply in a minimum of 15 gallons of water per acre. Irrigate with 1/2 inch of water if rainfall does not occur within 10 days after preemergence treatment. Where annual bluegrass is the major weed, use 1 qt. of Princep Liquid per acre (22 ml or 0.75 fl. oz./1,000 sq. ft.). Use 1-2 qt./A Princep Liquid (22-44 ml or 0.75-1.5 fl. oz./1,000 sq. ft.) for control of other weeds. However, do not exceed 1 qt./A of Princep Liquid per treatment on newly sprigged turfgrass or on hybrid bermudagrass.
For control of summer annuals which emerge after the initial application, apply an additional 1 qt./A Princep Liquid at least 30 days after the initial application, but not after June 1. However, do not make more than 2 applications per year.
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51 of 59 people found this answer helpful
I have used Dimension with moderate results. If I switch to simazine, how best to augment it (if at all) for a mix of grassy weeds and broadleafs, including Crown Vetch and Henbit?
Both Princep Liquid Herbicide and Dimension 2EW have henbit and many other weeds and grasses on the label for control so either would work well for your needs. We do not recommend mixing the two together as it would not give you any extra control. We contacted several of our experts in the herbicide field and reps at the manufacturers of the products we carry and they all came to use with the same answer. There are no pre-emergent herbicides that will control Crown Vetch. The only way to control it is post-emergent form or by taking the area to bare ground and reseeding with which ever grass you choose. We apologize we could not be of more help for your situation but some weeds like Crown Vetch and also Nutsedge just cannot be controlled prior to germination. Please let us know if you have any other questions.
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37 of 44 people found this answer helpful
We do not recommend mixing Trimec 992 and Princep Liquid Herbicide because they have different modes on action. You want to apply the Trimec earlier in the season and then when/if other weeds start growing, you can apply Princep Liquid Herbicide. Be sure that your type of turf is labeled for application of both products.
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4 of 6 people found this answer helpful
I am landscaping an area containing mature oak and hickory trees and would like to use Princep to prevent week growth under these trees and then use a mulch to cover the entire root areas.
Yes, Princep Liquid Herbicide can be used under mature trees and should pose no harm to them. Please refer to the product label for complete mixing and application instructions.
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6 of 6 people found this answer helpful
What is your recommendation for blueberries?
Princep Liquid Herbicide works as a pre-emergent herbicide to kill a variety of grass and broadleaf weeds. It is not labeled for blueberries. Can you tell us more about what you are treating for on or around blueberries so that we can offer you another product that will be effective?
Princep Liquid Herbicide is a pre-emergent that we carry labeled for knawel which is listed as german moss. Surflan is our most popular pre-emergent for sandburs/spurs if that is more what you are treating for.
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13 of 15 people found this answer helpful
Princep Liquid Herbicide is a pre-emergent weed control product and it will not control the weeds that have already emerged in your yard. According to the Princep product label: Apply Princep Liquid after September 1 (after October 1 for annual bluegrass) before emergence of winter annual weeds. Fall applications of Princep Liquid will control annual bluegrass, burclover, lawn burweed, common and mouseear chickweed, corn speedwell, henbit, hop clover, spurweed, and parsley-piert. Princep Liquid will also control these weeds soon after emergence. For control of summer annual weeds listed in the Product Information section of this label, apply Princep Liquid in late winter before the weeds emerge. Apply in a minimum of 15 gallons of water per acre. Irrigate with 1/2 inch of water if rainfall does not occur within 10 days after preemergent treatment. Where annual bluegrass is the major weed, use 1 qt. of Princep Liquid per acre (22 ml or 0.75 fl. oz./1,000 sq. ft.). Use 1-2 qt./A Princep Liquid (22-44 ml or 0.75-1.5 fl. oz./1,000 sq. ft.) for control of other weeds. However, do not exceed 1 qt./A of Princep Liquid per treatment on newly sprigged turf grass or on hybrid Bermuda.
For control of summer annuals which emerge after the initial application, apply an additional 1 qt./A Princep Liquid at least 30 days after the initial application, but not after June 1. However, do not make more than 2 applications per year.
We do not recommend applying RoundUp to the area because it is a non-selective herbicide that will eradicate anything that is sprayed with the product. Including the desired vegetation.
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23 of 30 people found this answer helpful
Princep Liquid Herbicide is a pre-emergent that will prevent weeds from germinating in the soil and will last about 4-6 months in the soil. It will not kill any actively growing weeds. Timing is always key when applying pre-emergents and will vary by region and the best person to ask about application timing is your local master gardener who works at your local cooperative extension office.
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22 of 26 people found this answer helpful
Yes, you can add a dye indicator such as Turf Mark Blue to Princep Liquid Herbicide.
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22 of 23 people found this answer helpful
I tried it with the hose end sprayer and it was difficult, so was wondering about a battery back-pack sprayer.
Yes, it not actually recommended to use a hose end sprayer with Princep Liquid Herbicide or any other herbicide as they are no where near as accurate for application or even as a backpack sprayer. Using a backpack sprayer like you mentioned would be the ideal form of application and just follow the product label instructions for mixing.
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3 of 4 people found this answer helpful
I will be planting some evergreen trees there in the future.
You will need to use 0.75-1.5 fl. oz./1,000 sq. ft depending on your target weed.
The first thing you need to know when using an herbicide such as Princep Herbicide is that the exact amount of water you dilute it with is not important. It is only important to make sure you are using the correct amount of product per 1,000 sq ft of lawn. Use too much and you risk damaging your lawn, use too little and you will not get adequate results. You will need to use 0.75-1.5 fl. oz per 1,000 sq ft . To decide how much water you want to use, you should mark a 1,000 sq ft area, fill your sprayer with WATER ONLY, and start walking and spraying just as if you were doing the actual application of herbicide. When you are done walking and spraying the 1,000 sq ft area note how much water it took you to spray that area, and that is the amount you will want to mix 0.75-1.5 fl. oz of product with for each 1,000 sq ft area that needs to be treated.
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8 of 11 people found this answer helpful
Princep Liquid Herbicide
Rating: 4.1 (11 Reviews / 81 Q&A)
