When To Plant Alfalfa In Ky

If you’re planning a new stand in the Bluegrass State, knowing exactly when to plant alfalfa in KY is the most important step for success. Getting the timing right sets the stage for a strong, resilient crop that can thrive for several years.

This guide gives you the clear, practical advice you need. We’ll cover the best windows for spring and fall planting, how to prepare your soil, and tips for getting a great stand established. Let’s get started.

The optimal planting times for alfalfa in Kentucky are during two specific windows: late summer to early fall and early spring. The absolute best and most recommended time is from mid-August to early September. A secondary window is from late March to mid-April.

Fall planting is generally prefered because it gives seedlings time to develop a strong root system before winter dormancy. They then explode with growth the following spring. Spring planting can work well, but it comes with more pressure from weeds and potential summer drought stress.

Why Fall Planting is Often Best

Planting in late summer or early fall offers several key advantages for Kentucky growers. The cooler temperatures and typically more reliable moisture reduce stress on young seedlings.

Here are the main benefits:

Less Weed Competition: Many aggressive summer annual weeds have slowed down by late August, giving alfalfa seedlings a better chance.
Strong Root Development: The plant focuses energy on building a deep taproot instead of top growth, creating a more drought-tolerant stand.
Ideal Soil Conditions: Soils are usually warm from the summer, which promotes quick germination, while air temperatures are cooling.
Full Production Next Year: A fall-planted stand is ready to take off in early spring, often allowing for a first cutting in late May or early June.

The Spring Planting Window

Spring planting is a good option if you missed the fall window or experienced a winterkill on an existing stand. The key is to plant as early as soil conditions allow.

Aim for late March through mid-April. The soil should be dry enough to work without compacting it—it must not be wet and muddy. Early planting is crucial because it allows the alfalfa to develop its root system before the heat and potential dry spells of summer arrive.

The main challenges with spring planting include greater competition from weeds and the risk of a dry July stressing the young plants. You’ll need to be more vigilant with weed control.

Soil Temperature is Your Guide

Regardless of the calender date, soil temperature is a critical factor. Alfalfa seeds germinate best when soil temperatures are between 65°F and 85°F. You can use a simple soil thermometer to check at a 2-inch depth.

In Kentucky, soils usually reach this range in early April for spring and remain there through much of September for fall planting. Don’t rush planting into cold, wet soil; seeds will rot or germinate poorly.

Step-by-Step Planting Guide for Kentucky

Following the right steps after choosing your date makes all the difference. Here’s what you need to do.

1. Soil Testing and Preparation

This is the most important step you shouldn’t skip. Alfalfa requires well-drained soil with a pH between 6.5 and 7.0 for optimal growth. It also needs good fertility levels.

Test your soil at least 3-6 months before planting, especially if you need to adjust pH with lime, as it works slowly.
Ensure phosphorus (P) and potassium (K) levels are in the high range according to your soil test report.
Choose a field with good internal drainage. Alfalfa will not persist in soggy, poorly drained soils.

2. Variety Selection

Not all alfalfa varieties are the same. Choose one suited for Kentucky’s climate and your specific goals.

Select a variety with a fall dormancy rating suitable for Kentucky (typically a 3, 4, or 5). A FD4 is a very common choice.
Look for varieties with resistance to pests like the potato leafhopper and diseases like Phytophthora root rot.
Buy high-quality, certified seed. It’s an investment that pays back in yield and stand longevity.

3. Seeding Method and Rate

A firm, weed-free seedbed is essential. You can use a drill or broadcast seeding followed by a cultipacker.

The recommended seeding rate for pure alfalfa stands is 15 to 20 pounds per acre.
Plant seeds ¼ to ½ inch deep. Never plant deeper than ½ inch, as alfalfa seedlings are not strong enough to emerge from deep planting.
Use a cultipacker before and after seeding to ensure good seed-to-soil contact. This is critical for moisture uptake.

4. Post-Planting Management

Your job isn’t done after the seed is in the ground. Proper early care ensures establishment.

Weed Control: Scout fields regularly. Use herbicides labeled for new alfalfa seedlings if broadleaf weeds or grasses become a problem.
First Year Harvest: For fall plantings, do not cut in the seeding year. Allow the plants to store energy for winter. For spring plantings, you can often take a first cutting when the stand is about 70 days old, usually in early bloom.
Fertility: Follow soil test recommendations annually to maintain pH and potassium levels, which are critical for winter survival.

Common Mistakes to Avoid

Even experienced farmers can make errors that hurt their stand. Here’s what to watch out for.

Planting Too Deep: This is the number one cause of seeding failure. Alfalfa seed is tiny and cannot be buried.
Poor Soil pH: Trying to grow alfalfa in acidic soil (low pH) will always result in a weak, thin stand that dies out quickly.
Planting into Weedy Fields: Always start with a clean seedbed. Weeds will outcompete slow-growing alfalfa seedlings.
Incorrect Seeding Rate: Don’t try to save money by skimping on seed. A thin stand from the beginning invites weeds and reduces total yield potential.

FAQs: Planting Alfalfa in Kentucky

Can I plant alfalfa in October in Kentucky?

Late October planting is generally to late and risky. The seedlings will not have enough time to develop the crown and root reserves needed to survive the winter. Mid-August to early September is the safe target.

What is the best cover crop for alfalfa?

It’s usually best to plant alfalfa without a nurse crop in Kentucky. However, if erosion is a major concern on sloping land, a light seeding of oats (1-2 bu/acre) can be used. The oats must be removed early as haylage to prevent shading out the alfalfa.

How long does an alfalfa stand last in Kentucky?

With excellent management—proper pH, fertility, harvest timing, and drainage—a Kentucky alfalfa stand can remain productive for 4 to 6 years, sometimes longer. Stands often begin to thin out after the 3rd or 4th production year.

Can I frost seed alfalfa in Kentucky?

Frost seeding (broadcasting seed on frozen ground in late winter) is not reliable for alfalfa. It works better for clovers. Alfalfa seed requires precise depth control and a firm seedbed, which is best achieved with a drill.

What should I plant after alfalfa?

Alfalfa leaves nitrogen-rich soil. Corn often performs very well following an old alfalfa stand, as it can use the residual nitrogen. Always take a soil test after terminating alfalfa to guide your fertilizer needs for the next crop.

Choosing the right time to plant is the foundation of a successful alfalfa field. For most Kentucky farmers, targeting that late summer window from mid-August to early September gives your new stand the greatest advantage. Remember to always start with a soil test, choose the right variety, and pay close attention to seeding depth. With careful planning and managment, you can establish a high-yielding alfalfa stand that provides quality forage for seasons to come.