Give Your Seeds and Plants the Best Start
Plant in most commercial potting media — including Pro-Mix, Sunshine Mix, Farfard Mix, Metro Mix, Jiffy Mix — and your plants get nutrients sufficient for four to six weeks. At that point, you need to begin fertilizing when that nutrient supply is exhausted. If you see bottom leaves yellowing and growth ending, you’ve waited too long.
The problem can be corrected by top-dressing. Nowadays my go-to product is Bloom, a fertilizer made locally from biosolids scientifically processed by the Blue Plains Waste Water facility.
The formula is one-quarter teaspoon each for plants growing in cell packs; one teaspoon for three-inch pots; one rounded teaspoon for four-inch pots. In larger containers, including hanging baskets, top-dress an eight- or 10-inch container with one cup six weeks after planting.
A single top dressing will provide the nutrient needs of most potted plants for eight to nine weeks.
Never blend Bloom in any commercial potting media prior to seeding or transplanting seedlings.