Soil pH Calculator — How Much Lime or Sulfur to Add
Free soil pH calculator — enter your current pH, target pH, and soil type to get the exact amount of lime or sulfur to add per 100 square feet. Includes pH ranges for 30+ vegetables.
OGW Editorial Team
Companion Planting Tool — Find the Best (and Worst) Plant Pairings
Free companion planting tool — enter any vegetable, flower, or herb and instantly see which plants help it thrive and which ones to keep away. Based on proven pairing data for 60+ crops.
Seed Starting Guide – Everything You Need to Start Seeds Indoors
The complete seed starting guide for home gardeners — when to start, how to set up your station, the best mix, germination troubleshooting, hardening off, and free planning tools.
When and How to Fertilize Seedlings — The True Leaf Rule Explained
Seedlings need fertilizer at exactly the right time — too early burns roots, too late starves plants. Here’s the true leaf rule, what to feed, and how much for every growth stage.
Why Seeds Won’t Germinate — 7 Causes and Exactly How to Fix Each
Seeds that won’t sprout almost always have one fixable cause. Here are the 7 most common reasons seeds fail to germinate — with a soil temperature table, real product recommendations, and the quick reference diagnostic chart.
Best Seed Starting Trays — 72-Cell, 50-Cell, Self-Watering & What to Actually Buy
Seed starting trays are not all the same. Here’s the honest breakdown of 72-cell vs 50-cell vs soil blocks, what self-watering trays actually do, and which setup to buy for which crops.
Best Seed Starting Mix — DIY Recipe vs Store-Bought (2026 Guide)
What’s actually in seed starting mix, which store-bought brands work best, and whether making your own DIY seed starting mix is worth it — with a tested recipe that costs half as much.
How to Harden Off Seedlings Without Shocking Them (7-Day Schedule)
Hardening off seedlings is the bridge between indoor growing and outdoor thriving. Here’s the exact 7-day schedule, the signs that go too fast, and the common shortcuts that backfire.
15 Seed Starting Mistakes That Kill Seedlings (And How to Avoid Them)
These 15 seed starting mistakes are responsible for most seedling failures at home. Learn what goes wrong, why it happens, and exactly how to fix each one.
How to Germinate Seeds Fast — Paper Towel Method, Pre-Soaking & Heat Tricks
Three proven techniques that speed up seed germination: the paper towel method, pre-soaking, and heat mat optimization — with which crops benefit most from each.