December 2025 WeedRead: Alfalfa That Works for You: Conventional vs. Roundup Ready
Our WeedRead series highlights monthly insights from Rocky Mountain Supply agronomists, each focused on helping you make the most of your fields. In this December article, we’re discussing alfalfa and exploring the options and benefits available to today’s producers.
Alfalfa Seed
Let’s talk alfalfa! We have something for everyone when it comes to alfalfa. Whether you are a dairyman, commercial hay producer, or you want to put up enough hay to feed a few horses, we have you covered!
Here in Montana, we are very demanding and expect a lot out of our alfalfa. In most cases, with us being such a livestock-producing part of the country, we are going to hay it hard, graze it even harder, throw some of the coldest temperatures on the lower 48 at it, and expect it to break domancy with a smile on its face, ready to go to work. That’s why we chose CROPLAN Alfalfa. We stand behind the best genetics in the country and let them go to work for you!
We are privileged to bring the best genetics in the country to our customers. Forge Genetics owns cropland alfalfa and is the world’s largest alfalfa breeder. They strive to bring new and improved genertics and traits to the table for you every single year.
Roundup Ready Alfalfa
Utilizing Roundup Ready and controlling weeds established for the stand’s life is essential to keep competition away. Alfalfa HATES competition! We also want to help deliver as much clean, free alfalfa to our livestock as possible. The importance of not allowing a seedbed of weeds to take the investment can not be stressed enough. We depend on our alfalfa stands to meet our yield goal. Weeds are the most limiting factor in yield; a quart of Buccaneer 5 (glyphosate), 30 days after seeding, will help keep those weeds at bay! Two great options are:
RR Presteez – 3.2 Fall Dormancy & 1.2 Winter Hardiness
RR Graze N Hay – 2.9 Fall Dormancy & 1.8 Winter Hardiness (Geared to be grazed with livestock)
Conventional Alfalfa Benefits
Conventional alfalfa is also a great option! Especially if you have a market that is more driven to want an alfalfa and grass mix. From a crop protection standpoint, you can keep broadleaf pressure out by using 4 – 6 oz of conventional herbicide (Raptor, Pursuit, Pemex, Vulture) once a year. A few great conventional options include:
Gunner AA – Fall dormancy 4.8 & 1.2 Winter hardiness.
Maxi Graze – Fall dormancy 2.0 & 2.0 Winter hardiness (geared to be grazed with livestock).
Legendairy AA – Fall dormancy 3.4 & 1.1 Winter hardiness.
Frequently Asked Questions
Q: How important is seedbed prep?
A: Alfalfa does best when planted in a FIRM seedbed!
Q: Do you suggest drill or broadcast?
A: We always suggest drilling to ensure proper seeding depth and seed-to-oil contact. Our applicators do a great job of blowing seed on for customers who may not have the time or equipment. When broadcasting, increase the seed rate by 2%—4%.
Q: What is the Nutrient Management Importance?
A: If you feed it, it will grow! Phosphorus, Pot Ash, or Sulfur are great nutrients for alfalfa. But do not forget the importance of micronutrients such as Boron, Manganese, and Zinc.
Q: Seeding rate and seeding depth?
A: The seeding rate is a personal preference, but under irrigated conditions, it is suggested that the amount be 16-18 lbs/acre. Under Dryland conditions, it is suggested that you do 10-12 lbs/acre. Seeding depth should be 1/4 – 1/2″.
If you have further questions beyond what is listed above, please do not hesitate to reach out to your local agronomist. We are here to help you make the best decisions for your operation and long-term success!
