Yarrow is a classic, cottage-style cut flower perfect for a rustic bouquet or as filler in, well, any arrangement. While Yarrow is a perennial in most zones, it’s productive and blooms beautifully in the first year. However, Yarrow takes a long time to grow and must be started indoors. It’s important to start Yarrow indoors from seed at the right time, to ensure your seedlings don’t become rootbound yet still make the most of your growing season. With this guide and free Yarrow Start Date Calculator, you’ll learn the perfect time to start Yarrow seedlings indoors. The best part – it doesn’t matter what zone you’re growing in!

Plant Start Date Calculator

Finding your Last Frost Date

Not sure when your last frost date is? Don't know what a last frost date is? Don't worry!

If you're in Canada or the United States, our other free tool is here to help. It finds the nearest weather station to your location and displays frost dates calculated from historical data. As an added bonus, it also calculates different probabilities of frost on any given day - making it the most data-driven frost tool you'll find online.

If your garden enjoys a warm micro-climate or you're prepared to protect your plants with frost cloth, consider selecting an earlier, high-risk date to extend your gardening season. Conversely, if you're in a colder area or prefer to avoid the risk of frost, the low-risk date is your safest bet.

If you're gardening or farming outside the USA or Canada, try a quick internet search for "your closest town or city + last frost date" to find the date you need. Alternatively, speaking with local gardeners, flower farmers or nurseries about the last frost date they use can be very helpful.

Your Growing Zone: Forget About It

While understanding your plant hardiness zone is crucial for perennials to survive winter lows, it actually doesn't really matter when you're starting Yarrow from seed indoors. The focus should instead be on your last frost date, marking when it's safe to transition frost-sensitive seedlings outdoors without the threat of more frost. That being said, Yarrow is a perennial up to Zone 2 - so it will survive the winter in most places.

By using your last frost date and knowledge of how quickly Yarrow grows, we can precisely predict the perfect indoor starting time for these seedlings with our calculator, making sure they're ready for transplant when you are. If you start them too early, they'll become root-bound, stunted and productivity will suffer. If you start them too late, you might miss out on a huge head-start to the season - or even blooms from Yarrow altogether!

Using The Yarrow Seed Indoors Date Calculator

Our tool for calculating the best start date for starting Yarrow seedlings indoors is simple: all you have to do is input your last frost date, and it will offer a suggested planting timeframe. It's that simple!

For cut flower enthusiasts looking to elevate their gardening game or flower farmers growing many different varieties, consider trying out Bloom Manager. It's an all-in-one planning tool built specifically for cut flowers that not only aids in seed starting calculations but also helps in mapping out your garden or farm's layout, scheduling, and essential tasks, including predicting harvest times—all for free!

Let's Get Growing

  • Soil Preparation: Choose a sterile, high-quality seed-starting mix for optimal drainage and a clean environment. Ready your trays or soil blocks, ensuring the soil is moistened first.
  • Sowing Time: Sow Yarrow seeds on the soil surface, as they need light to germinate. Press them gently into the mix without covering them. Keep the soil moist, watering delicately after sowing.
  • Germination Period: Yarrow seeds may take 10-14 days to germinate - be patient and keep the lights on!
  • Light Needs: Ensure your Yarrow seedlings receive plenty of light to prevent weak, leggy growth. A bright window is good, but grow lights are best.
  • Watering: Keep the soil consistently moist but not waterlogged.
  • Pinching: There's no need to pinch Yarrow.

As your last frost date approaches, start the hardening off process to get your Yarrow used to outdoor conditions. Begin with limited time in a shaded area, gradually increasing their exposure to sunlight and outdoor conditions over about a week. After this period, they're ready for transplant, spaced about 12 to 18 inches apart.

With your Yarrow in the ground, anticipate the arrival of their blooms in late summer.

Happy growing!

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