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The best time to plant Red Russian kale is in the cool weather of early spring or late summer for a fall harvest.
This variety of kale absolutely thrives when temperatures are between 60°F and 70°F, and it even gets sweeter after a light frost.
If you’re wondering about the specifics of when to plant Red Russian kale in your garden, you’ve come to the right place.
In this post, we’ll break down the perfect planting windows, how to handle different climates, and tips for getting the most tender, flavorful leaves.
Let’s dig in and figure out the ideal timing for your region.
When to Plant Red Russian Kale Based on Your Climate
Knowing when to plant Red Russian kale starts with understanding your local frost dates.
This hardy green is a biennial that acts like an annual in most home gardens, and it can tolerate temperatures down to 20°F once established.
The golden rule is to plant it so it matures in cooler weather, not the heat of summer.
1. Early Spring Planting for a Summer Crop
For a spring harvest, you should plant Red Russian kale about 4 to 6 weeks before your last expected frost date.
This means you can start seeds indoors in late winter and transplant them out as soon as the soil is workable.
If you prefer direct sowing, you can plant seeds right into the garden as soon as the ground thaws in early spring.
The key here is that Red Russian kale seeds will germinate in soil as cold as 40°F, so you don’t need to wait for warm weather.
When you plant Red Russian kale this early, it will give you tender baby leaves in about 30 days and full-sized leaves in 50 to 60 days.
Pro tip: A light frost after planting won’t hurt the young seedlings, so don’t panic if a cold snap hits.
2. Late Summer Planting for a Fall Harvest
The most popular time to plant Red Russian kale is actually in late summer for a fall harvest.
Count backward from your first expected fall frost date, and aim to plant about 6 to 8 weeks before that date.
So if your first frost is around October 15, you’ll want to plant your Red Russian kale in late August or early September.
Because the weather is cooling down, the plants will grow slower, which actually concentrates the sugars and makes the leaves sweeter.
When you plant Red Russian kale in late summer, you can harvest it well into late fall and even early winter if you use a cold frame or row cover.
This fall crop is often considered the best because the flavor is unmatched after a few frosts.
3. Winter Planting in Mild Climates
If you live in zones 7 through 10, you can plant Red Russian kale in autumn for a winter harvest.
In these warmer regions, the plant will grow through the winter months and produce leaves without going dormant.
You should plant it in early fall, around September or October, so it establishes roots before the coldest days arrive.
And in very mild areas like the Pacific Northwest or southern California, you can even plant Red Russian kale again in January for a spring harvest.
The plant may slow down in the coldest weeks, but it rarely dies, and it will bounce right back as the days lengthen.
How to Determine the Right Planting Time for Your Area
Let’s be honest, the exact date when to plant Red Russian kale varies a lot depending on where you live.
Instead of relying on a calendar date alone, you should use your local frost dates as your guide.
Here’s a simple way to calculate your ideal planting window.
1. Find Your Last and First Frost Dates
Your last spring frost date is the average date when the final cold snap happens.
Your first fall frost date is the average date when freezing temperatures begin.
You can find these dates by searching your zip code online or checking your local agricultural extension office.
Once you have these, you can mark your calendar for the two windows: early spring and late summer.
2. Use Soil Temperature as a Backup Signal
Even if the calendar says it’s time, the soil might be too cold or too warm.
Red Russian kale seeds germinate best in soil that is between 45°F and 75°F.
If the soil is warmer than 80°F, the seeds may go dormant or grow weak, spindly seedlings.
Use a soil thermometer to check the ground temperature before you plant Red Russian kale.
If it’s too warm in late summer, wait a week or two or water the soil to cool it down.
Bonus tip: Mulching around your plants keeps the soil cool in summer and insulates it in winter.
3. Consider Your Growing Season Length
Red Russian kale takes about 50 to 60 days to reach maturity from seed.
If you have a short growing season, you’ll need to transplant seedlings to save time in the spring.
If you have a long growing season, you can do successive sowings every 3 weeks until about 8 weeks before your first frost.
This gives you a continuous supply of tender leaves all season long.
Common Mistakes to Avoid When Planting Red Russian Kale
Even experienced gardeners can make mistakes with timing when it comes to this leafy green.
Avoid these pitfalls to ensure you plant Red Russian kale at the perfect time.
1. Planting Too Late in Spring
The biggest mistake is waiting until May or June to sow seeds in most northern regions.
When you plant Red Russian kale that late, the young plants hit the summer heat and bolt quickly.
Bolting means the plant sends up a flower stalk, which makes the leaves turn bitter and tough.
To avoid this, always treat it as a cool-season crop and get it in the ground early.
2. Planting Too Early in Late Summer
On the flip side, planting too early in August while the soil is still scorching hot isn’t great either.
The seeds will struggle to germinate in hot soil, and the plants may suffer from heat stress.
Wait until the daytime temperatures start to dip below 80°F regularly before you plant Red Russian kale for fall.
3. Ignoring Microclimates in Your Yard
Your garden might have spots that are warmer or cooler than the rest of the property.
A south-facing wall can be a warmer microclimate, allowing you to plant a bit earlier in winter or later in fall.
Shaded areas stay cooler in summer, which can help you plant Red Russian kale even in early August.
Pay attention to where the frost settles and where the sun hits to fine-tune your timing.
So, When to Plant Red Russian Kale?
When to plant Red Russian kale comes down to two main windows that align with cool weather.
The first window is early spring, about 4 to 6 weeks before your last frost, for a tender summer crop.
The second window is late summer, about 6 to 8 weeks before your first fall frost, for the sweetest fall harvest.
You should plant Red Russian kale in mild winter zones during autumn so you can harvest all winter long.
The most reliable approach is to use your local frost dates, check the soil temperature, and avoid the extremes of high heat.
By timing it right, you’ll enjoy beautiful, frilly purple-tinged leaves that are perfect for salads, sautés, and smoothies.
Hope this guide clears up any confusion and gets you growing this stunning, cold-hardy green soon.