When To Plant Forage Sorghum

The best time to plant forage sorghum is after the last frost has passed and soil temperatures have warmed to at least 60°F.
 
This warm-season grass absolutely thrives in the heat, so timing your planting correctly is the difference between a lush, high-yielding forage crop and a disappointing stand.
 
If you’ve been wondering when to plant forage sorghum for grazing, hay, or silage, the short answer is late spring through early summer, depending on your region.
 
Getting the timing right matters because forage sorghum seeds need warm soil to germinate quickly and establish strong roots.
 
In this post, we’ll break down the ideal windows for planting forage sorghum, the key soil temperature targets, and a few regional tips to help you maximize your yield.
 
Let’s dig into the details so you can plan your planting schedule with confidence.
 

When To Plant Forage Sorghum: The Ideal Window

The ideal time to plant forage sorghum is when the soil temperature at a 2-inch depth consistently stays at or above 60°F.
 
This typically falls between late April and mid-June for most temperate regions, but your exact window depends on your local climate.
 
Planting forage sorghum too early, when soils are still cold and wet, is a common mistake that leads to poor germination and seedling diseases.
 
On the flip side, planting too late in the summer can shorten the growing season and reduce your total forage yield before the first fall frost.
 
The sweet spot is to aim for a planting date that gives the crop at least 90 to 120 frost-free days to reach maturity.
 
You can plant forage sorghum successfully when nighttime temperatures are consistently above 50°F, as this signals that cold snaps are behind you.
 

1. Soil Temperature Is Your Best Guide

Checking soil temperature is more reliable than just guessing by the calendar when you want to know when to plant forage sorghum.
 
Use a soil thermometer and check at 2 inches deep in the morning for several days in a row.
 
If the reading stays above 60°F, you’re in the clear to plant forage sorghum without worrying about cold shock.
 
When soil temps are between 60°F and 65°F, germination will be steady, and seedlings will emerge within 7 to 10 days.
 
If you plant forage sorghum in soil that’s warmer, say 70°F to 85°F, you’ll see even faster emergence and more vigorous early growth.
 
Warm soil encourages deep root development, which helps the plants handle drought stress later in the season.
 

2. Regional Planting Windows for Forage Sorghum

Your location plays a huge role in determining the best time to plant forage sorghum.
 
In the southern United States, where springs warm up early, you can plant forage sorghum as early as late March or early April.
 
For the Midwest and upper South, mid-April to late May is the prime planting window for forage sorghum.
 
In the northern Plains and cooler mountain regions, you’ll want to wait until late May or even early June to plant forage sorghum.
 
No matter where you are, always watch the extended forecast and avoid planting forage sorghum right before a cold, rainy spell.
 
A sudden drop in temperature right after planting can cause seeds to rot in the ground before they ever sprout.
 

3. Day Length and Frost Considerations

Forage sorghum is a short-day plant, meaning it flowers when daylight hours start to decrease, which is why timing matters so much.
 
If you plant forage sorghum too late, the plants may not have enough vegetative growth before they start heading out.
 
This is a critical point when deciding when to plant forage sorghum because early planting gives you more leafy biomass.
 
Also, keep in mind the first expected fall frost in your area when you plant forage sorghum.
 
Forage sorghum is extremely frost-sensitive, and a single cold night will kill the plants instantly.
 
So, you want to count backward from your first frost date to ensure at least 90 days of growth before that happens.
 

Best Practices For Planting Forage Sorghum Successfully

Once you’ve nailed down when to plant forage sorghum, you also need to focus on how to set it up for success.
 
Preparing your seedbed ahead of time will make a big difference in how well your forage sorghum establishes.
 

1. Seed Depth and Spacing

Plant forage sorghum seeds at a depth of 1 to 1.5 inches, especially if you’re planting into moist soil.
 
If your soil is on the sandy side, go slightly deeper, but never go deeper than 2 inches.
 
Seeding rates typically range from 5 to 10 pounds per acre for dryland conditions and up to 15 pounds for irrigated fields.
 
Proper spacing ensures good airflow, which reduces the chance of fungal diseases in your forage sorghum stand.
 

2. Fertilizer and Soil Prep

A soil test is your best friend before you plant forage sorghum, as it tells you exactly what nutrients are missing.
 
Forage sorghum is a heavy nitrogen feeder, so you’ll usually need to apply 50 to 100 pounds of nitrogen per acre.
 
Incorporate phosphorus and potassium based on your soil test results before you plant forage sorghum.
 
Good seed-to-soil contact is crucial, so make sure your seedbed is firm and free of large clods.
 

What If You Miss The Ideal Planting Window?

Sometimes life gets busy, and you might miss the perfect time to plant forage sorghum in the spring.
 
Don’t worry, because you can still plant forage sorghum successfully in early summer as a double crop.
 
As long as you plant forage sorghum by mid-July in most regions, you can still get a decent yield before fall.
 
The key is to choose a shorter-maturity hybrid that matures in 75 to 85 days if you’re planting late.
 
Also, be sure to plant forage sorghum into adequate moisture, as summer heat can dry out the soil quickly.
 
Late-planted forage sorghum may produce less total biomass, but it can still provide excellent grazing or silage value.
 

So, When To Plant Forage Sorghum?

When to plant forage sorghum comes down to soil warmth, frost safety, and your regional climate.
 
Plant forage sorghum when the soil is at least 60°F and all danger of frost has passed for the best results.
 
Aim for late spring to early summer, between late April and mid-June for most areas, to maximize your growing days.
 
You can plant forage sorghum later in the summer, but expect reduced yields if you push past mid-July.
 
Always monitor soil temps and the long-range forecast before you plant forage sorghum to avoid costly failures.
 
Pay attention to your first fall frost date so your crop has enough time to mature fully.
 
I hope this guide has cleared up any confusion about when to plant forage sorghum and set you up for a productive season.