Crop Timeline Calculator

Plan when to sow, transplant, and harvest your vegetables. Calculate backwards from target harvest dates or forwards from sowing dates with popular UK crops.

Crop & Growing Details

Growing Method

Set to 0 for direct sow only

From transplant (or sow if direct)

Which date do you know? The others will calculate automatically

Fixed milestone

Your Timeline

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Enter a date to get started

Select a known date above to calculate your full timeline

Need Climate-Aware Schedules?

This calculator uses generic days to maturity. Leaftide calculates optimal planting dates based on your location's frost dates, daylight hours, and historical climate data.

Start Planning Your Garden →

How to Use This Calculator

1. Choose Your Crop

Select from popular UK vegetables to load typical growing times, or use "Custom timeline" to enter your own timing from a seed packet or variety guide.

2. Select Growing Method

Choose whether you'll start seeds indoors and transplant, or direct sow outdoors. Root vegetables like carrots and parsnips must be direct sown.

3. Adjust Growing Days

Fine-tune the days to transplant and days to harvest based on your climate, variety, or seed packet recommendations. All values are editable.

4. Pick Your Known Date

Select which date you want to work from - sowing, transplanting, or target harvest date. The calculator will work backwards or forwards to determine the other dates.

Common Use Cases

Planning Spring Sowing

Work backwards from your last frost date to determine when to start tomatoes, peppers, and other frost-sensitive crops indoors.

Succession Planting

Calculate when to sow lettuce, rocket, or radishes every 2 weeks for continuous harvests throughout the season.

Target Harvest Dates

Working backwards from a specific date? Enter your target harvest date to find out when you need to sow for summer barbecues or autumn storage crops.

Climate Adaptation

Adjust the default growing days to match your local climate - crops grow faster in warmer regions and slower in cooler areas.

Why This Calculator Is Approximate

This timeline calculator uses generic days-to-maturity data from seed catalogues. Real-world growing times depend on many factors:

  • Climate & Temperature: Warm weather accelerates growth; cool weather slows it down
  • Daylight Hours: Many crops are photoperiod-sensitive and grow differently in long vs short days
  • Frost Dates: Your last spring frost and first autumn frost define your safe growing window
  • Variety Differences: Early, mid, and late-season varieties have very different maturity times
  • Soil & Care: Fertility, watering, and plant health all affect growth speed

For more accurate, climate-aware schedules, Leaftide uses your location's frost dates, historical weather data, and daylight hours to calculate optimal planting windows.

Transplant vs Direct Sow: Which Method?

Best for Transplanting:

Tomatoes, peppers, chillis, aubergines, courgettes, cucumbers, pumpkins, brassicas (broccoli, cabbage, cauliflower, brussels sprouts), lettuce. These benefit from a head start indoors and transplant well.

Must Direct Sow:

Carrots, parsnips, radishes, beetroot, onions, potatoes. Root vegetables don't transplant well because transplanting damages the taproot. Always sow these directly in their final position.

Can Do Either:

Beans (broad, french, runner), peas, lettuce, chard, kale, spinach, rocket. These can be direct sown for simplicity or started indoors for earlier harvests. Choose based on your space and schedule.

Note: Growing times vary by variety, climate, and conditions. Always check your specific seed packet for recommended timing and local frost dates.