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I don’t just plan my seed sowing calendar: I colour code it, alphabetise it, and give my seeds a motivational pep talk. My actual garden has…well, weeds and enthusiasm, but today I’m here to share how you can make a custom seed sowing calendar to get ahead.
So you have decided what you want to grow in your cutting patch, well now it’s time to pull all together into a practical plan known as a seed sowing calendar. Creating a well thought out calendar doesn’t just save time, it also maximizes your harvest, prevents overcrowding, and ensures your plants are ready to plant at the perfect moment.
Let’s dive into how to create a customized sowing schedule so you can visualize your entire season at a glance.
Gather Information and Tools
To get started, you’ll need:
- Last frost dates for your area (in York this is typically early/mid May). You will use this date as your anchor point and work backward when scheduling your seed sowing. I have a post explaining all about frost dates here
- Seed packets for specific information on each plant’s sowing, transplanting, and harvest times. Every seed packet has important details that will guide your schedule. Learn to decipher your packets and fill gaps in your info here
- Any gardening journal or notes you keep. Utilise experiences in your garden from last year (and other seasons) to fine-tune your schedule.
Reflect on previous years in the garden
Reflecting on past experiences ensures you’re not repeating mistakes and helps you optimize for better results.
Did your cosmos grow too leggy indoors before planting out? You might need to sow them later this year.
Did your dahlias flower late in the season? Perhaps start them earlier indoors and try pre-sprouting tubers.
Did you have a glut of a particular flower, or not enough of another? Adjust your sowing quantities to avoid overproduction or underproduction.
Ask yourself the following questions, looking back to plan ahead for next season:
- Which plants struggled in your garden? Can this be fixed?
- Did anything flower late in the season?
- Which flowers do you wish you had more or less of?
- Were any plants super productive? Or incredibly unproductive
- Did you end up with gaps in the beds that could have been utilised with better planning?
Build Your Seed Sowing Calendar
Now, let’s create a Gantt chart…ok that’s just a technical term for a method which visually maps out your entire seed-starting season. This will help you keep track of when to sow, transplant, and harvest throughout the year. This can be done on paper or electronically.
Here’s how to structure it:
- List your plants on the left
- Create columns for each week of the year, starting in January. I like to do weekly as this allows me to produce weekly sowing lists and stay on top of my sowing with minimal thinking. This is important to me when Spring is busy busy busy! If you would rather have monthly columns and monthly lists then feel free to approach it this way.
- Indicate the week of your last frost. For me this is week 20.
- Use your seed packet information and for each plant, shade in the cells to indicate the timing for:
- Seed sowing indoors
- Transplanting outdoors (e.g. after the last frost)
- Direct sowing
- Expected harvest windows
Choose a colour for each task so you can quickly identify.
- Now we need to figure out when to start your seeds. Thankfully this is simple. Your seed packet should list the number of weeks before your last frost date that the seed should be sown. If it doesn’t, there are plenty of valuable resources online with this information. The Floret library is unparalleled, with a wealth of free information to support flower growers! Floret Library – Floret Flowers
- Mark this week on your calendar: I tend to start all my seeds undercover. If you have a mixture of indoor and direct sowing then use different colours, or symbols, or codes (eg GH and DS) to flag where the seeds are going. This is your first sowing date.
This will give you a clear visual overview of your entire growing season.
Factor in Succession Planting and Staggered Harvests
To keep your garden productive all season, plan for succession sowing of fast-growing crops. For example, for a steady supply of single stemmed sunflower blooms, sow every 10 days to 3 weeks. Schedule these multiple sowing dates in your chart to stay organized.
Pull together weekly lists
Creating a seed sowing calendar is an invaluable tool for maximizing your garden’s potential. By factoring in frost dates, seed packet guidelines, and your own past experiences, you’ll be able to sow and harvest at the optimal times. With your chart in hand, you’ll be organized, prepared, and ready to enjoy a productive and beautiful 2025 growing season.
Let me know if you would like a digital template based off my sowing chart!
Happy planning!
Nat
