Comparison: Best Schultz Plant Fertilizer (Updated | Nov 11th)

Consider the scale of your planting project: an 8‑oz bottle like the SPF45170 is ideal for larger beds, multiple containers, or frequent watering, while the 4‑oz versions are perfect for small indoor pots or occasional use. Larger bottles usually offer a lower price‑per‑ounce, giving better long‑term value if you fertilize regularly. Smaller bottles let you test a formula without committing to a big quantity.

Both formulas share the same 10‑15‑10 nutrient ratio, but the 8‑oz bottle includes extra packaging details such as weight and a broader label for universal use, while the 4‑oz bottle is more compact and often marketed for hobbyists. The larger size gives a better cost per ounce, whereas the smaller size offers convenience and less waste for occasional growers.

Yes, Schultz designs most of its liquid feeds, including the All Purpose 10‑15‑10 and the African Violet Plus, to be used at seven drops per quart of water. This consistent dosing simplifies mixing and helps prevent over‑fertilizing. However, always check the label for any product‑specific adjustments, especially for specialty formulas like cactus feed.

For indoor foliage, houseplants, and container vegetables, the All Purpose 10‑15‑10 (available in 4‑oz or 8‑oz) works well because it provides a balanced nutrient mix without excess salts. Outdoor beds benefit from the same formula but in larger quantities, while specialty plants like African Violets or cacti should use their dedicated formulas (8‑14‑9 for violets, 2‑7‑7 for cacti) for optimal bloom and growth.

The violet formula has a lower nitrogen level (8) and higher phosphorus (14) to encourage strong root development and vibrant blooms, which is ideal for delicate flowering houseplants. In contrast, the 10‑15‑10 blend offers a more balanced approach for general growth across a wide range of plants. Using the violet‑specific feed can produce better flower quality on African Violets and similar bloomers.

Cactus and succulent plants thrive on low‑nitrogen, moderate‑phosphorus, and low‑potassium nutrition, which the 2‑7‑7 blend provides, reducing the risk of leggy growth. While you can use the universal 10‑15‑10, it may promote softer, less drought‑tolerant tissue. For dedicated succulent collections, the specialized formula offers better long‑term health and is a worthwhile investment.

Multi‑packs typically lower the overall cost per bottle and ensure you have a spare on hand for refills, which is handy for consistent feeding schedules. They also reduce packaging waste compared to purchasing single bottles repeatedly. If you plan to fertilize multiple plant types or maintain a regular routine, a 2‑pack delivers both convenience and savings.