Offers the brand's Smart Release system that feeds plants for 4 months. Versatile, as it promotes big, vibrant blooms and hearty vegetables. Strengthens root systems and doesn't burn when used as directed.
A few reports of packages arriving with damage. Some users didn't get the results they were expecting.
A popular, multi-purpose fertilizer that won't burn when directions are followed. Economical. Improvements in plants are noticeable with recommended use – every 1 to 2 weeks.
Some owners report damage to small, delicate plants such as herbs and seedlings, but harm can be avoided in most cases by closely following recommended guidelines.
Stands at the top of the our list for being affordable, effective and fast. It's concentrated, and owners rave about results such as 2-day germination and lush foliage. Effective for most plants and won't cause burns.
It's somewhat smelly, but the natural wintergreen oil additive helps keep the odor in check.
A small package with big potential – 7 drops per quart of water is packed with micro-nutrients that works on indoor and outdoor plants. Users have reported exceptional results when used on seedlings.
You may have to purchase several bottles if you have a lot of plants to fertilize.
Organic and easy to use – capable of producing vibrant colors and enhanced bloom aromas. Ideal for blooming plants and flowering trees. We love that it is odor-free.
It's pricey, and doesn't produce noticeable results in all plants, including some types of vegetables.
We recommend these products based on an intensive research process that's designed to cut through the noise and find the top products in this space. Guided by experts, we spend hours looking into the factors that matter, to bring you these selections.
Healthy soil isn’t always a guarantee. The earth in your area may not provide the necessary nutrients for a lush garden. The potting soil mix you’ve added to your garden beds may be deficient in some nutrients. Over time, plants also leach nutrients from the soil.
Garden fertilizer is a vital gardening tool and a simple way to help vegetables, flowers, and other plants flourish in soil where nutrients are scarce or present in the wrong quantities.
The BestReviews team wants to help you grow flowers, vegetables, and herbs with ease. Our shopping guide covers the various types of garden fertilizers, including information on macronutrient ratios and what type of fertilizer may be best for your gardening needs. When you’re ready to make a purchase, our product list will help guide you toward the best products available. Happy gardening!
Here are the three main forms of garden fertilizer, how they’re applied, and the advantages of each.
Fertilizers in granular form are dry. You can apply granular fertilizers with a spreader or use the built-in shaker top on some canisters. You can easily see how much you’re applying and where, so you can control the application. Many dry formulas are water soluble and can be diluted using a watering can, making it easy to fertilizer and water your garden at once. There are two types of granular fertilizers.
Slow-release fertilizer provides the steady release of nutrients over an extended period of time, so frequent application isn’t necessary.
Quick-release fertilizer delivers nitrogen to plants almost immediately, but it requires frequent application. This fertilizer isn’t intended for general plant maintenance because it can harm plants if poorly applied. Use it to address specific deficiency issues.
Most liquid fertilizers need to be diluted with water and are applied using a canister and hose. Gardeners can also manually mix liquid formulas with water in a watering can. Liquid fertilizer is very easy to apply and is quickly absorbed through leaves and roots, making the nutrients readily available to plants. This type of fertilizer requires frequent application. The downside is that it easily washes away in the rain and can contaminate nearby water sources.
Compressed fertilizer in the shape of spikes that you stick in the ground is convenient and easy to use. This form of fertilizer slowly releases nutrients over time. The spikes don’t require dilution and don’t need to be precisely measured, so this is an excellent choice for the novice gardener or those short on time.
When shopping for garden fertilizer, keep these factors in mind.
The number on that fertilizer bag you’re eyeing? It’s the ratio of macronutrients – nitrogen (N), phosphorus (P), and potassium (K) – in the mix. For example, a bag marked “4-4-4” means that it contains a 1:1:1 ratio of these elements: 4% nitrogen, 4% phosphorus, and 4% potassium, and the rest is filler. Some mixes include trace amounts of micronutrients like calcium. Most other nutrients are needed in smaller amounts or are readily available in the soil. Each macronutrient has a particular function.
Typical NPK ratios and their benefits include the following:
1-1-1: All-purpose fertilizer
1-2-1: Root systems
1-2-2: Fruit setting and flowering
3-1-1: Leafy growth
The above ratios are guidelines. The fertilizer that will help your plants depends significantly on the nutrient composition of your soil. Adding a fertilizer intended to encourage green growth won’t do you any good if your soil is already rich in nitrogen. Only a soil test can alert you to deficiencies that need to be addressed.
Even if you’ve discovered an imbalance in your soil through testing, don’t overdo it! Too much fertilizer can burn and even kill your plants. Carefully read the fertilizer package instructions and dilute accordingly if needed.
Synthetic vs. organic fertilizers
Fertilizers are available in both synthetic and organic formulas.
Timing fertilizer application just right is the key to developing a lush, healthy garden. Applying fertilizer at the wrong time is a waste of time and money because the nutrients may soon be blown or washed away. The following are some fertilizer application guidelines.
Have your soil tested before applying fertilizer. That way you’ll know what nutrients are already present or lacking in the soil. Timing the application of fertilizer correctly won’t matter if you’re feeding your plants nutrients they already have in abundance.
Bone meal and blood meal are meat industry by-products. Vegan and vegetarian gardeners should read fertilizer contents carefully.
Watch the concentration of nutrients. Keep in mind that a fertilizer with a high concentration of one nutrient isn’t necessarily better than one with a lower concentration. A high concentration in a quick-release formula may cause root burn or create a nutrient imbalance in your soil. A lower concentration of a slow-release formula, on the other hand, is a better option.
Fertilizers range in price from under $10 to $80. Smaller bags for container plants are the least expensive and won’t set you back more than $20. On average, expect to pay between $0.10 to $0.50 per square foot to fertilize a garden or lawn. If you plan on hiring someone to do the work, you’ll need to factor in the extra cost. Tools such as fertilizer spreaders are another expense to take into consideration.
Unsurprisingly, larger bags and bins of fertilizer cost more. Specialty fertilizers with added micronutrients may be more expensive, too. Organic fertilizers also usually cost more than synthetic options. When fertilizing large swaths of land, buying in bulk is the most economical option.
Q. Are fertilizer and compost the same thing?
A. Kind of. Compost amends the soil, while fertilizer delivers nutrients directly to plants and not the soil. Fertilizers still end up in the soil, though, so it’s important to be careful not to add them haphazardly. Unlike most fertilizers, compost contains many trace nutrients, such as boron. Compost is often classified as an organic fertilizer, but compost doesn’t have the same concentrated amounts of NPK as synthetic fertilizer.
Q. Is there a way to know if my soil is nutrient deficient without a soil test?
A. Deficiencies can be hard to spot, and the only way to know for sure is to get your soil tested. Phosphorous deficiency usually results in stunted plants, but a number of other factors can contribute to weak growth. Yellowing leaves can be a sign of potassium deficiency, but, again, it’s tough to tell for sure that your soil is lacking this specific nutrient.
Q. I live near a water source. Can I use fertilizer in my garden?
A. Opt for organic fertilizer to prevent contamination of ponds, lakes, rivers, and wells. Organic formulas typically aren’t as concentrated as synthetic fertilizers and are designed to release slowly. Unless you pour organic fertilizer everywhere without concern, it shouldn’t pose a threat to surrounding ecosystems.