Know what goes into the answer.

Our approach, from the start

Grownestia is being built in phases. My Garden, four calculators, ten source-backed plant profiles and ten practical guides are live; other calculators and resources are not live yet. These principles describe both the current calculation approach and how we intend to build and maintain future resources.

Show the formula

Each calculator explains the relationship between its inputs and output. Soil and Mulch use rectangular volume. Rainwater collection uses catchment area × rainfall × a user-selected efficiency: 1 mm over 1 m² equals 1 L, while 1 inch over 1 ft² is approximately 0.6233766 US gallons. Calculators normalize units, retain precision internally and round only for display.

Keep units consistent

Tools label every input and result. Unit conversions happen before arithmetic, and the calculators document conversion factors so feet, inches, meters and centimeters are not silently mixed. Converting a length is different from converting an area or a volume.

State measurement assumptions

Results will explain the shape and dimensions assumed by the calculation. A rectangular-bed estimate, for example, should specify whether it uses internal growing dimensions. Irregular spaces, uneven ground, existing material and settling can change the amount needed.

Make spacing assumptions explicit

The Plant Spacing Calculator uses a cell-allocation geometry model. It normalizes units, divides each bed dimension by the user-provided spacing, floors each direction to complete cells and reports remaining space. It calculates layout geometry rather than inventing a crop-specific spacing recommendation.

Keep garden plans local and explicit

My Garden stores user-entered rectangular bed dimensions and optional labels in versioned browser storage on the user's device. It does not infer plant-specific spacing or send garden records to a Grownestia backend.

Configured layouts call the same complete-cell model as the Plant Spacing Calculator. Their counts are geometric estimates based on user-entered spacing, not guarantees of plant capacity, health or yield.

Make rounding visible

Calculators retain precision during calculations and round only the displayed result. A material estimate and a purchase quantity are different: whole bags are rounded up, and the tool shows that rule with the bag size used.

Let buffers be a choice

Where a waste or buffer percentage makes sense, it is an explicit, optional input. Tools distinguish the base quantity from the additional allowance. They do not silently add a universal buffer to every estimate.

Estimates have limits

A calculated quantity is a planning estimate, not a guarantee of plant health, yield, coverage or cost. Regional conditions, climate, soil texture and drainage can all affect what works in a garden. Cultivars and varieties can also need different spacing and care.

Product-specific application rates and safety instructions take precedence over a generic calculator. Check the label or supplier guidance before buying or applying a material.

Source plant information carefully

Plant profiles favor identifiable sources such as university extension publications and public horticultural organizations. Citations are attached to the claims they support, and each profile lists the original sources and the date Grownestia reviewed them.

When sources describe different varieties or growing systems, the profile keeps those ranges separate and explains the context instead of averaging them. Regional planting calendars are not presented as universal advice.

Review and update openly

Released tools are checked against worked examples, unit conversions and boundary cases. Editorial review checks whether cited guidance supports the text and whether its context is clear.

Published resources include meaningful review dates when that work has actually happened. Corrections to formulas or assumptions will be documented. We do not label material as expert verified without a real, identified review.

Keep guide advice in context

Editorial guides use identifiable horticultural sources for factual recommendations. When guidance varies by region, crop, construction or growing method, the guide keeps that context visible and does not silently average conflicting numbers.

Calculator formulas remain separate from horticultural recommendations. A guide may explain how to apply a chosen depth or spacing, while the calculator performs only the stated geometry and unit conversion.