The library

Long-form guides for the people who grow.

Practical and editorial growing guides organized by pillar. Field-guide rigor for Apprentices, Growers, Educators, and Stewards alike. New guides ship weekly.

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All guides For Growers For Apprentices For Educators For Stewards

Pillar 01

Substrate Library →

Reference entries on growing media. Field-guide style: each entry self-contained, citable, with mix recipes for common plant types. Updated monthly.

Root system in clear glass with substrate cross-sectionFoundation

Foundation

The Root Zone

What plants are actually asking for from substrate, and the three-ingredient recipe that fixes most struggling houseplants.

Apprentices Growers
Substrate ingredients arranged on linen backgroundGoing deeper

Going deeper

How Substrate Actually Works

Air-filled porosity, capillary water, perched water tables, CEC, pH, and the oxygen variable nobody measures. The physics underneath every potting decision.

Growers Educators
Botanical specimen tray with horticultural ingredientsReference

Reference

The Aroid Ingredient Glossary

Pumice, perlite, zeolite, charcoal, coir, sphagnum, castings — every ingredient that goes in a chunky aroid mix, with the Guild's verdict on each. Including the ones we avoid.

Growers Educators
Substrate ingredients in ceramic bowls with brass scalePractice

Practice

Designing a Mix: The Logic Behind the Ratios

The framework behind every substrate recipe. How to work backward from what the plant needs and adapt any published mix for your own humidity, temperature, pot, and feeding style.

Growers Educators
Six labeled mason jars on a walnut workbench, each showing a different aroid substrate recipe through the glassSystem

System Overview

The Petruscio Substrate System

Six recipes, three layers, zero bark. The map of which mix fits which use case — from root rot recovery to tissue culture acclimation to everyday aroid maintenance.

Growers Educators
Terracotta pot half-buried in pure white pumice and charcoal mineral substrate, recovering aroid plantlet beside a handwritten recovery timelineRecovery

Recovery Recipe

ICU Mix v5

Seventy percent mineral, ten percent zeolite, zero bark. The recovery substrate the Guild reaches for when a plant arrives with black roots — plus the week-by-week protocol that gets it back.

Growers
Tissue culture plantlet in a clear deli cup of white pumice, beside a humidity dome and a handwritten TC Day 14 kraft tagSpecialist

Specialist

Tissue Culture Acclimation

Substrate is a chassis, not a cure. What actually drives TC plantlet survival, and the mineral-based mixes the Guild uses across hundreds of acclimations.

Growers Educators
Map of substrate ingredients traced to their global origins: peat, coir, bark, pumice, perlite, zeolite, charcoal, vermicompostFinale

Finale · Stewards-tier

Substrate at Scale: Why a Bag of Mix Is a Supply Chain

Every ingredient in a chunky aroid mix has a backstory. Tracing each one back to its origin (bog, beach, forest, volcano, mine) for Growers who think about how their bench connects upstream.

Stewards Growers

Pillar 02

Plant Profiles →

Long-form portraits of single specimens, treated as botanical subjects — substrate, light, water, humidity, propagation, common failure modes. Editorial register, not whimsical.

Compendiums Genus Deep Dives
Featured Individual Profiles

Pillar 03

Field Manual →

The working-grower's reference shelf. Pest IDs, repotting protocols, light troubleshooting, cross-genus substrate notes — formatted as scannable dossiers, written for growers who keep collections. New entries biweekly.

Pillar 07 · Seasonal · Summer 2026

California Natives →

A summer-2026 series on California native plants for Bay Area gardens. Editorial plant lore plus practical sourcing and timing — when to plant for fall establishment and where to source ethically through CNPS chapter sales. Twelve entries, weekly Saturdays, June through August.

Pillar 06

The Workshop →

The tools that actually do the work. Systematic comparative reviews — we test 4–6 products in a category over 4–8 weeks of real use, then publish the methodology, results, and the Winner / Best Buy / Also Recommended hierarchy. America's Test Kitchen, for gardening tools. New entries biweekly on Wednesdays.

Pillar 04

Garden Planner →

Tools, calendars, and timing references for growers planting now.

Pillar 05

The Window Box →

Scrappy balcony, condo, and small-space gardening — the urban edge of the Guild. Honest about what works and what doesn't when "yard" isn't on the table. Folded in from Downtown Mister Gardener.

In production

Coming to the Member Library.

The Guild's first batch of printable, designed-for-the-bench PDFs is being drafted now — deep, long-form Member-only Grow Guides on subjects we don't publish on the open site. None are shipping yet; this is the roadmap.

Each will carry the Guild seal and your member name, sized to print on standard paper or take to the garden center on your phone. Founding Members get them as they ship.

Become a Founding Member

Member PDF · Drafting

Substrate Recipes for the Twenty Most Common Houseplants

One printable page per plant, with substrate ratio, watering cadence, and red-flag failure modes — the Guild's bench notes, formatted to live next to your collection.

Member PDF · Drafting

The TC Acclimation Field Guide

Step-by-step protocol for moving tissue-culture plantlets from agar to soil — including the Guild's iodine-based deflasking method.

Member PDF · Researching

California Natives for Small Spaces

Forty native species that thrive in containers, with a county-by-county compatibility matrix and water-budget notes.

Member PDF · Researching

The Repotting Calendar

Month-by-month repotting windows broken out by plant family — the working calendar the Guild uses for its own collection.