Harvest Calculator

Dayboro Harvest Date Calculator

Know when to pick — based on Dayboro's local growing conditions and real-time weather data

The most common question in any Dayboro garden: "Is it ready yet?" Rather than guessing or squeezing tomatoes until they bruise, this calculator uses your planting date combined with real-time temperature data from our weather station to estimate when each crop will be ready for harvest. Because growing speed in the Dayboro valley depends on temperature — and our temperatures are not what the Bureau of Meteorology thinks they are.

Generic harvest calculators use textbook "days to maturity" figures based on ideal conditions. That's fine if you live in a controlled greenhouse. In the Dayboro valley, where summer days push past 35°C and winter nights drop to 4°C, growth rates shift dramatically with the seasons. A tomato planted in October will mature faster than one planted in March because it spends more time in the optimal temperature range. This calculator accounts for that.

Harvest Date Calculator

Estimate harvest dates for 28 crops using Dayboro's real-time growing conditions

Calculate Harvest Date

Earliest
Expected
Latest
Growth Progress 0%
Current Temperature Suitability
Germination:
Disclaimer: Harvest date estimates are approximations based on average days-to-maturity data adjusted for current Dayboro temperatures. Actual harvest timing depends on variety, soil quality, watering, pest pressure, and microclimate factors this calculator cannot fully account for. Use these dates as a guide, not a guarantee. Always check your plants for maturity signs (colour, firmness, size) before harvesting.
Data from Dayboro Weather Station — local growing conditions, not Brisbane averages

Understanding Harvest Times in the Dayboro Valley

Every seed packet has a "days to maturity" number printed on the back. Those numbers come from trials run under controlled conditions — usually in temperate North American or European climates with consistent day lengths and moderate temperatures. In the Dayboro valley at 130 metres elevation in the D'Aguilar Range, conditions are different enough to make those numbers misleading.

Summer temperatures regularly exceed 35°C, which stresses many vegetables and can actually slow growth. Winter nights drop to 4–8°C, which is fine for brassicas but brings warm-season crops like tomatoes to a near standstill. The "days to harvest" for a tomato might be 70 days in ideal conditions, but in Dayboro it could be 55 days in summer (more heat units per day) or 100+ days if you planted late and it's growing through a cool autumn.

Growth rate depends on temperature: Plants don't grow according to the calendar — they grow according to accumulated heat. A warm week in January contributes more to maturity than a cold week in July. This calculator adjusts the textbook "days to maturity" based on how closely Dayboro's current temperature matches each crop's optimal growing range.

How Temperature Affects Growing Speed

Every vegetable has an optimal temperature range for growth. Within that range, the plant grows at its maximum rate and the seed-packet estimate is roughly accurate. Outside that range, growth slows — sometimes dramatically.

The relationship works like this: if the current temperature is within the crop's optimal range, growth proceeds at a factor of 1.0 (normal speed). If it's too cold, the growth factor drops as low as 0.3 (about a third of normal speed). If it's too hot — and yes, Dayboro summers can be too hot for some crops — the factor also drops, though less severely. This is why lettuce bolts in February (too hot, stressed growth) but thrives in May (right in its comfort zone).

Optimal ranges for common Dayboro crops

Crop Type Optimal Range Days to Harvest Germination
TomatoWarm18–30°C60–90~7 days
LettuceCool12–20°C45–60~5 days
CarrotCool15–25°C70–80~14 days
BroccoliCool15–25°C70–100~7 days
BeansWarm18–27°C50–70~7 days
PotatoCool15–22°C90–120~14 days
CucumberWarm18–30°C50–70~7 days
SpinachCool10–20°C40–50~7 days
CapsicumWarm20–30°C60–90~10 days
ZucchiniWarm18–30°C45–60~7 days
PumpkinWarm18–30°C85–120~7 days
CornWarm18–30°C60–90~7 days
RadishCool12–22°C25–35~4 days
GarlicCool10–22°C150–210~14 days
Sweet PotatoWarm20–30°C90–150~14 days
StrawberryPerennial15–25°C60–90~14 days
AsparagusPerennial15–25°C365–730~21 days

The table above shows a selection of the 28 crops in the calculator. Notice the enormous range in days to harvest: radishes can be pulled in under a month, while asparagus takes a year or more to establish. Garlic planted in March won't be ready until September or October. Planning your garden around these timelines means you'll have something to harvest in every month of the year.

Frequently Asked Questions

How accurate are the harvest date estimates?
The estimates are based on average days-to-maturity data adjusted for current Dayboro temperatures. In practice, they're a solid starting point rather than an exact prediction. Soil quality, watering consistency, pest pressure, and the specific variety you're growing all affect the actual harvest date. The "expected" date assumes average conditions; the "earliest" and "latest" dates bracket the likely range. Most Dayboro gardeners find the actual harvest falls somewhere within that window.
Why does the calculator say my crop will take longer in winter?
Plants grow based on accumulated heat, not calendar days. In Dayboro's cooler months (May–August), warm-season crops like tomatoes, beans, and capsicum grow significantly slower because temperatures are below their optimal range. The calculator's growth rate adjustment reflects this reality. Cool-season crops like broccoli, lettuce, and peas actually grow faster in winter because they're in their preferred temperature range.
What does the "growth factor" mean?
The growth factor is a multiplier from 0.3 to 1.2 that adjusts the textbook harvest timeline. A factor of 1.0 means the crop is growing at normal speed (temperature is within optimal range). Below 1.0 means growth is slower than expected. Above 1.0 means conditions are ideal and the crop may mature slightly faster than the seed packet suggests. The factor is calculated from the current temperature relative to each crop's optimal range.
Can I use this for crops not in the list?
The calculator includes 28 common vegetables and herbs suitable for the Dayboro region. If your crop isn't listed, find a similar one with comparable temperature preferences and days to maturity. For example, most chilli varieties behave similarly to capsicum, and rocket (arugula) is comparable to lettuce but slightly faster. The growth rate adjustment will still be useful even if the exact days-to-maturity figure isn't perfect.

Methodology

The calculator uses a temperature-based growth adjustment formula:

Growth Factor Calculation

For each crop, the current temperature from the Dayboro weather station is compared to the crop's optimal growing range:

  • If the temperature is within the optimal range: growth factor = 1.0
  • If below the optimal minimum: factor = 0.5 + 0.5 × (temp / optMin)
  • If above the optimal maximum: factor = 0.5 + 0.5 × (1 - (temp - optMax) / 15)
  • The factor is clamped to the range 0.3 – 1.2

Adjusted Days to Harvest

The textbook midpoint of the days-to-maturity range is divided by the growth factor to produce the adjusted estimate: adjustedDays = baseDays / growthFactor. A growth factor of 0.5 (cold conditions) effectively doubles the expected time, while a factor of 1.2 (ideal conditions) shortens it by about 17%.

Data Sources

Current temperature is fetched from /weatherdata/weather-current.json, which is updated every 5 minutes from the Dayboro weather station (Ecowitt GW2000 + WS90, 130m elevation). Crop data (days to maturity, optimal temperature ranges, germination periods) is drawn from multiple horticultural references and calibrated against local Dayboro growing experience.

Tagged , , ,
Secret Link