Predict seasonal demand for plants and inputs. Adjust for weather, growth stage, and promotions easily. Make smarter orders, reduce waste, and avoid shortages always.
| Scenario | Area | Base rate | Season / Stage | Weather | Weekly forecast | ROP | Recommended order |
|---|---|---|---|---|---|---|---|
| Mulch peak planting | 250 m² | 0.18 bags/m²/week | Spring / Flowering | Avg 22°C, Rain 18 mm | ≈ 65.2 bags/week | ≈ 120.4 bags | ≈ 160.0 bags |
| Irrigation fittings | 120 m² | 0.06 units/m²/week | Summer / Harvest | Avg 30°C, Rain 8 mm | ≈ 12.6 units/week | ≈ 23.8 units | ≈ 30.0 units |
| Potting mix winter | 80 m² | 0.12 bags/m²/week | Winter / Dormant | Avg 12°C, Rain 30 mm | ≈ 5.0 bags/week | ≈ 12.1 bags | ≈ 15.0 bags |
Garden demand rarely stays flat. Temperature swings, day length, rainfall, and planting calendars move sales and usage for soil, mulch, seed, starters, irrigation parts, and pest controls. The calculator converts these forces into structured multipliers, so you can compare Spring peaks against Winter slowdowns using one consistent baseline rate. It also supports promotions that pull demand forward.
Start with a normal week when supply and labor were stable. Divide total units used or sold by the cultivated area to obtain a per‑square‑meter weekly rate. Update the baseline by crop type or product line, because vegetables and ornamentals consume inputs at different intensities and schedules. If you lack history, begin conservatively and refine after two cycles.
Weather changes demand in two ways: it shifts growth speed and it changes the need for inputs. Higher temperatures can increase watering, fertigation, and replacement plant purchases, while heavy rain may reduce irrigation parts and water‑use products. Sensitivity settings let you tune how strongly your local climate influences the forecast. Keep adjustments moderate and review outcomes monthly to avoid overreacting.
Forecasting alone does not prevent stockouts. Lead time and review period define how long you must be protected from uncertainty. The calculator uses service level and demand variability (CV) to compute safety stock, then adds expected demand during the protection window to create a reorder point that aligns inventory with seasonal volatility. As suppliers extend lead times near peak season, ROP should rise.
When inventory position falls below the reorder point, the tool recommends an order quantity based on the larger of shortage‑to‑ROP and the economic order quantity. EOQ balances ordering costs and annual holding costs, which is essential for bulky items such as compost, potting mix, and mulch that consume space and tie up cash. Use export files to share decisions with teams across the season.
Use recent sales or usage by season and divide by your baseline week. If Spring demand is 20% higher than baseline, set 1.20. Start with defaults, then adjust after comparing forecasts to actuals.
CV is uncertainty: standard deviation divided by the mean demand. If weekly usage varies a lot, CV is higher. A higher CV increases safety stock and reorder points, reducing stockout risk at the cost of extra inventory.
Not always. For irrigation parts and water products, rain often reduces demand. For disease control or soil amendments, rain can increase demand. Use the rain sensitivity and your judgment to match how your item behaves locally.
Use 95% for most critical items during peak season and 90% for less critical items. Higher service levels increase safety stock. If storage space or cash is limited, lower service level can be a controlled tradeoff.
ROP equals expected demand during lead time plus the review period, plus safety stock. Safety stock uses a z‑value from the service level and demand variability. The result is the inventory position threshold that triggers reordering.
The tool compares the immediate shortage to the economic order quantity. EOQ can be larger because it reduces the total cost of ordering and holding over a year. For perishable items, you can cap the order to shelf-life limits.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.