Best Green Garden Fertilizers in 2026

SOURCE OF CALCIUM MAGNESIUM & CHELATED IRON: Many varieties of flowering plants require higher levels of these micronutrients. Our well-balanced formula is designed to specifically address any plant deficiencies that may be present.

CORRECTS COMMON PLANT DEFICIENCIES: Sometimes an unhealthy plant may be suffering from a nutrient deficiency or even too much of one nutrient. Our CalMag & Iron supplement effectively corrects and remedies these micronutrient plant deficiencies.

NUTRIENT UPTAKE AND ABSORPTION: This formulae efficiently supports nutrient uptake and absorption by addressing any plant deficiencies in the first place, thus successfully supporting the vegetative and flowering stage of your plants.

FOR ANY PLANT: Our Golden Tree formula is an all-in-one additive for any plant, tree, flower or bush. When used with a well-balanced fertilizer, Golden Tree helps improve soil/foliar nutrient conditions for better crop yields. In addition to improving overall plant nutrition, Golden Tree supports conditions for better plant establishment, nutrient uptake and abiotic stress tolerance.

GROW METHOD COMPATIBLE: No matter what grow method you’re using, Humboldts Secret Golden Tree solution will help feed growing plants. It’s designed to be compatible in all mediums - hydroponics, aeroponics, coco, DWC, soil, and every other type of growing method.

ESSENTIAL NUTRIENTS: Golden Tree can help provide essential nutrients to your garden that it isn't getting now. Our formula contains a mixture of kelp, carbs and minerals. It can be used in conjunction with other additives and fertilizers or as the only additive.

PREMIUM POTASSIUM SILICATE-BASED PRODUCT: Tree Trunk features advanced nutrients that will help the plants natural ability to strengthen its cell walls, resulting in thicker stalks and better branch development, as well as abiotic stress tolerance!

PLANT STRENGTH: Watch your plants grow by applying Tree Trunk liquid fertilizer. Hydroponic nutrients make our product suitable as quality indoor plant food.

ABIOTIC STRESS TOLERANCE: Tree Trunk is needed to ensure yield stability under abiotic stress and minimizes the environmental impacts on crop production.

FOR ANY PLANT: Our Golden Tree formula is an all-in-one additive for any plant, tree, flower or bush. When used with a well-balanced fertilizer, Golden Tree helps improve soil/foliar nutrient conditions for better crop yields. In addition to improving overall plant nutrition, Golden Tree supports conditions for better plant establishment, nutrient uptake and abiotic stress tolerance.

GROW METHOD COMPATIBLE: No matter what grow method you’re using, Humboldts Secret Golden Tree solution will help feed growing plants. It’s designed to be compatible in all mediums - hydroponics, aeroponics, coco, DWC, soil, and every other type of growing method.

ESSENTIAL NUTRIENTS: Golden Tree can help provide essential nutrients to your garden that it isn't getting now. Our formula contains a mixture of kelp, carbs and minerals. It can be used in conjunction with other additives and fertilizers or as the only additive.

COMPLETE MACRONUTRIENT PROFILE FOR PLANT NUTRITION: The combination of our Base A & B Bundle results in a complete feed for rapidly growing flowering plants and indoor plants. Our signature blend consists of Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, and more.

EASY-TO-USE TWO-PART SYSTEM: Simple use both bottles at equal rates throughout the entire growing cycle, from the beginning of the vegetative stage until the end of the flowering stage. We recommend application with every watering for maximum results.

COMPATIBLE WITH ALL GROWING MEDIUMS: Our clean-running formula is suitable for all grow mediums, including potting soil for indoor plants, hydroponics, aquaponics, and coco coir cultivations.

CONTAINS 7,000 UNITS OF ACTIVE ENZYME PER MILLILITER: Humboldts Secret Plant Enzymes is a highly concentrated enzymatic formula with 7,000 units/ml of active enzyme, making Plant Enzymes one of the strongest plant fertilizers on the market!

GREAT FOR HYDROPONICS AND COCO SUBSTRATE: Hydroponic and coco substrate benefit greatly from enzymes, as these typically have few microorganisms that digest dead root matter. Our formula is compatible with all growing mediums.

PLANT ENZYMES REJUVENATE SOIL: If you are reusing a soil cultivation, Plant Enzymes acts as plant food that will rejuvenate the soil by breaking down roots from the previous plant.

GROW THE PERFECT CROP: With our nutrients you will be able to grow the perfect crop. Our starter kit is proven to make the perfect harvest and it will save you time and pain to get there.

MAKES 125-150 GALLONS OF SOLUTION: Enjoy between 125 and 150 gallons of premium-quality nutrient solution to provide proper care and food for potting soil for indoor plants and outdoor plants. Base A & B (Quart Set), Flower Stacker (Quart), Calmag & Iron (Quart), Golden Tree (16 Ounce), Plant Enzymes (8 Ounce)

COMPATIBLE IN ALL GROW MEDIUMS: Perfectly suited for use in all growing mediums. Whether it's gravel, sand, coco mix, or hydroponics, Humboldts Secret Starter Kit will help your plants!

INCREASES NUTRIENT ABSORPTION: It’s created to effectively increase and optimize pH levels in various plant growth mediums including hydroponic nutrients pH, and maximize nutrient uptake and yield.

SAVES COSTS: A single bottle can go a long way. It’s a concentrated solution so you just need a few drops for maximum effectiveness. Enjoy outstanding output with minimal gardening cost increment!

CLEAN INGREDIENTS: This hydroponic pH controller is made with high-quality commercial-grade, water soluble potassium hydroxide and is 100% dye-free and additives-free, so it’s medium-friendly and ideal for your beloved botanicals.