Best Humboldts Secret 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!

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.

EXEMPT FROM EPA REGISTRATION: Humboldts Secret takes pride in creating products for your plants. You’ll be pleased to know that Flower Shield is made from products exempt from EPA registration under minimum risk pesticides according to FIFRA 25(b).

PEST MANAGEMENT: Flower Shield by Humboldts Secret is a pest management alternative that works as both a preventative and knock-down treatment for pests and fungus.

INSECTICIDE, PESTICIDE & MITICIDE: Our Flower Shield formula will kill mites, their eggs, and soft-bodied insects while also controlling powdery mildew. Weekly applications will create an environment that is lethal to pests and fungal spores, but not your plants.

EXEMPT FROM EPA REGISTRATION: Humboldts Secret takes pride in creating products for your plants. You’ll be pleased to know that Flower Shield is made from products exempt from EPA registration under minimum risk pesticides according to FIFRA 25(b).

PEST MANAGEMENT: Flower Shield by Humboldts Secret is a pest management alternative that works as both a preventative and knock-down treatment for pests and fungus.

INSECTICIDE, PESTICIDE & MITICIDE: Our Flower Shield formula will kill mites, their eggs, and soft-bodied insects while also controlling powdery mildew. Weekly applications will create an environment that is lethal to pests and fungal spores, but not 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.

Get your garden going with FoxFarm Grow Big, our liquid concentrate fertilizer that supports lush vegetative growth.

FoxFarm Big Bloom Liquid Plant Food is formulated for use on all plants and can be used every time you water. OMRI Listed and Registered CDFA Organic Input Material.

FoxFarm Tiger Bloom is a phosphorus fertilizer that contains nitrogen to support vigorous growth. FoxFarm Tiger Bloom is designed to encourage abundant fruit, flower and multiple bud development.

OSMOCOTE’S HIGHEST TOTAL NUTRIENT FORMULA: NPK = 14-14-14. Favored for seasonal vegetables and perennials. Promotes strong roots as well as vigorous and bountiful above-ground growth.

OSMOCOTE’S DIRECTIONS FOR USE: 1 lb. covers 40 sq. ft. (approx. 6½’ x 6½’). Mix into 1 – 3” of soil. Applicator included. Apply to vegetable gardens and mulched areas around ornamental trees / shrubs, and raised beds.

OSMOCOTE QUALITY: Osmocote is the original slow-release plant food. Decades of rigorous field testing confirm product effectiveness with hundreds of plant species in a variety of climate and soil conditions.

Highly fortified calcium, magnesium, and iron plant supplement formulated to correct common deficiencies

Supplement your existing nutrient program with Cal-Mag Plus

To Use: Mix well and use with every watering, as needed, for enhanced growth apply as a foliar spray

Instantly feeds to grow bigger, more beautiful plants versus unfed plants

Product packaging may vary

Use with the Miracle-Gro Garden Feeder or any watering can

Product 1: General Hydroponics FloraGro 2-1-6 delivers nutrients for structural and foliar growth

Product 1: Combine FloraGro 2-1-6 with FloraMicro and FloraBloom to create a nutrient mix tailor-made for your plants and their phase of growth (seedling, cutting, structural, flowering, or fruiting)

Product 1: Ideal for hydroponic applications and as a nutrient supplement for potted plants

Full of essential nutrients that help feed and nourish above and below the soil

Contains vital micronutrients to grow stronger, vibrant and more productive plants versus unfed plants

Feeds up to 3 months

The FloraSeries is a hydroponic-based nutrient fertilizer system that helps fulfill your plants’ nutrient needs at every stage of growth

Nutrients included are FloraMicro, FloraBloom, and FloraGro

FloraMicro is rich in nitrogen, calcium, and chelated micronutrients to help support fast-growing crops during all growth stages

For orchids and all acid loving plants

Feed every 2 weeks for colorful, beautiful orchids

Provides deep rich leaf color, beautiful blooms and strong root development

FEED YOUR PLANTS: Burpee's All-Purpose Organic Plant Food is formulated to keep your plants growing and happy throughout the season. Major nutrients as well as calcium, minor nutrients, and some of the beneficial microbes that help keep the soil and plants healthy are released immediately and continue to feed your plants for up to 3 months.

FOR VEGETABLES, FLOWERS & HERBS: Use this natural plant food for seed starting, bedding plants, vegetable gardens, trees, shrubs and flower containers. OMRI labeled organic. The custom blend promotes plant growth and more blooms! Great for indoor or outdoor plants.

ORGANIC CERTIFIED: OMRI listed for organic gardening use, this plant food safely keeps your soil and plants as healthy as they can be. Easy to apply granules release essential nutrients and deliver fast-acting results for all types of plants in your home garden. Follow instructions on the bag for how much plant food to apply.

Includes 1 lb. of Miracle-Gro Water Soluble All Purpose Plant Food

Trigger lock for one-handed feeding

Features three spray patterns: shower, jet and flat

Mixes only with water based solutions, will not work with oil based

Easily marks grass and lawns

Mix with herbicides, fungicides, pesticides, & fertilizers

Promotes more fruit and lush foliage (vs unfed)

Contains natural ingredients

Feed once per season in Spring and Fall

Free Measuring Spoon Enclosed For Easy And Precise Application

Features The Highest Safety Factor To Prevent Burning When Applied As Directed

Blended With An Enhanced Micronutrient Package Which Provides Optimal Nutrition For Strong Roots And Green Foliage

Grow stronger, healthier plants, with denser root systems and bigger crop yields.

Professional strength soil microbe superpack. Loaded with Mycorrhizae, Trichoderma, and billions of other beneficial soil microbes.

Works great for indoor and outdoor gardens. Use it on all your plants, crops, and trees; perennials and annuals.

Grow a beautiful vegetable garden

Flowers and foliage will be stronger and more colorful

Blooms will be more plentiful, fragrant and longer lasting

Proven Winners water Soluble fertilizer comes in an easy-to-use 2.5 lb. Container with a carrying handle and measuring scoop

24-12-17 fertilizer blend

Following the application rates on the container, apply at least every week, or every third watering

A three-pack of favorite liquid fertilizers from FoxFarm

Grow Big produces lush, vegetative, compact growth

Tiger Bloom is an ultra-potent, fast-acting, high-phosphorus fertilizer

Scotts Turf Builder Triple Action is a three-in-one formula that kills weeds, prevents crabgrass, and feeds grass to build thick, green lawns

Controls existing listed lawn weeds, including dandelion, clover, dollarweed, ground ivy, chickweed, plantain, henbit, and english daisy

Prevents crabgrass for 4 months (will not kill existing crabgrass); prevents other listed grassy weeds from invading your lawn

PROMOTES ROOTING: Rooting hormone grows new plants from cuttings.

GROW CUTTINGS: Works with most popular home, garden and greenhouse varieties.

ROOT NEW FAVORITE PLANTS: Helps African violets, roses, poinsettias, philodendrons, geraniums, coleus, woody ornamentals and more grow from cuttings.