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When it comes to growing beautiful flowers in your garden, you obviously need to provide plenty of sun and water. But what about flower fertilizers? Yes, you'll need those, too! In order to pick the right fertilizer, keep an eye out for the "N-P-K ratio." That stands for nitrogen, phosphorus, and potassium and the ratio indicates each nutrient's percentage in the bag. These ingredients play a part in promoting plant health: Nitrogen pushes healthy leaf growth, phosphorous helps build strong roots and blooms, and potassium promotes vigor. Here are the best flower fertilizers to make your garden a showpiece!
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Not only do your garden beds need a boost of fertilizer, but flowers in planters or containers also need to be regularly fertilized, because watering causes nutrients in these plants to leach out of the soil more quickly. There are several different fertilizer application methods to try, including slow-release granular formulas that you mix into the soil, spikes you insert near the root zone, and water soluble liquids to add to your watering can.
Many organic fertilizers are available, but you'll want to be careful: The term “organic” is not regulated for fertilizers, so just about anyone can put it on the label. If organic is important to you, however, look for products with the Organic Materials Review Institute (OMRI) seal. It's an independent nonprofit organization that certifies which products are compliant with USDA organic farming standards. Now that you're fully informed, read on for our top flower fertilizers for every type of bloom!
This powdered 15-30-15 formula has plenty of phosphate to ensure strong flower growth. It's easy to mix into your watering can and use every one to two weeks. Plus, it has no odor—which is great if you have nosy pets that are attracted to the scent of organic fertilizers. You can use it for both annuals and perennials.
| N-P-K Ratio | 15-30-15 |
|---|---|
| Plant types | All annual and perennial flowers |
Give seedlings a boost when you set them in the garden with this starter fertilizer. Its NPK ratio of 2-4-2 will help promote strong root development for baby plants. Use it for flowers as well as vegetables and other plants. Plus, it's safe for pets!
| N-P-K Ratio | 2-4-2 |
|---|---|
| Plant types | Flowers, vegetables, potted plants, bedding plants, transplants, trees, shrubs |
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Jobe’s Organics Rose & Flower Fertilizer
This granular fertilizer with a NPK ratio of 3-4-3 is ideal for both roses and other flowers. It's OMRI listed and contains beneficial soil bacteria as well. Apply at planting to promote root growth and disease resistance and then every six weeks after.
| N-P-K Ratio | 3-4-3 |
|---|---|
| Plant types | Roses and other flowers, flowering shrubs |
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Osmocote Smart-Release Plant Food
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Osmocote Smart-Release Plant Food
This slow-release granular formula lasts up to six months, so you won't need to fuss with it every week. Its NPK ratio of 15-9-12 will ensure fast, lush growth. Use it indoors and outdoors for hundreds of plant species! It's also easy to sprinkle around existing plants with a handy pre-measured scoop.
| N-P-K Ratio | 15-9-12 |
|---|---|
| Plant types | Indoor and outdoor flowers and plants |
Don't want to buy separate fertilizers for all your plants? This organic all-purpose granular fertilizer has active soil microbes and a NPK ratio of 6-4-5. It's a good general fertilizer for everything from plants that are edible like vegetables to those that are ornamental, both annual and perennial.
| N-P-K Ratio | 6-4-5 |
|---|---|
| Plant types | Annual and perennial flowers, vegetables |
While not exactly a fertilizer, worm castings can be beneficial to your planting beds. It's actually the digested “soil” produced by worm farming! The NPK ratio is 1-0-0, but they also contain micronutrients and beneficial microbes, and they improve drainage and soil structure. They have a mild, earthy scent that's not overwhelming, and you only need to use a handful at a time.
| N-P-K Ratio | 1-0-0 |
|---|---|
| Plant types | Indoor and outdoor flowers, vegetables |
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Neptune's Harvest Fish and Seaweed Fertilizer
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Neptune's Harvest Fish and Seaweed Fertilizer
This fertilizer has a NPK 2-3-1 ratio and is made from fish and seaweed to give your flowers (and other greenery!) a gentle organic boost. It's also listed for OMRI use. Mix this liquid into your watering can for quick results. But be aware it smells strongly of fish! Some curious pets may be attracted to the smell until it settles after a day or two.
| N-P-K Ratio | 2-3-1 |
|---|---|
| Plant types | Indoor and outdoor flowers and plants, vegetables, fruit, grass |
This granular extended release formula is mixed into the soil or sprinkled around existing plants like hanging baskets. It contains a gentle NPK 3-4-5 formula as well as beneficial microbes to improve soil health. Some pets will be attracted by the initial odor, so be careful when you apply it!
| N-P-K Ratio | 3-4-5 |
|---|---|
| Plant types | Roses, other annual and perennial flowers, hanging baskets |
9
Burpee Organic Rose and Bloom Granular Plant Food
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Burpee Organic Rose and Bloom Granular Plant Food
Formulated specifically to keep your roses and other flowers happy, this organic fertilizer is great for container gardens, flower beds, and bushes. The NPK 4-6-4 ratio feeds plants immediately, then lasts for up to three months. This organic granular formula is OMRI listed and helps promote root development and more colorful blooms.
| N-P-K Ratio | 4-6-4 |
|---|---|
| Plant types | All types of roses and flowering plants |
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Add this liquid NPK 10-15-10 fertilizer to your watering can for a super-fast jolt of nutrients! The dropper makes it so easy to measure out the correct amount (seven drops per quart of water) without making a mess. It's a great all around option if you have lots of greenery inside and out.
| N-P-K Ratio | 10-15-10 |
|---|---|
| Plant types | Indoor and outdoor flowers, vegetables, fruit, trees, shrubs |
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Neptune's Harvest Rose and Flowering Formula
This liquid organic fertilizer is OMRI listed and contains a NPK ratio of 2-6-4. The increased phosphorus of this formula will help boost your flowers' blooms and help them survive if your area is susceptible to drought. There's also a mild odor that fades quickly.
| N-P-K Ratio | 2-6-4 |
|---|---|
| Plant types | Roses and other flowers, potted plants, vegetables, fruit, grass |
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Scotts Super Bloom Water Soluble Plant Food
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Scotts Super Bloom Water Soluble Plant Food
With a NPK ratio of 12-55-6, this is some of the most powerful flower food on the market. Give your flowering plants a super-charged boost of this every one to two weeks. Just make sure to follow the instructions as listed so you don't burn your blooms.
| N-P-K Ratio | 12-55-6 |
|---|---|
| Plant types | Outdoor flowers, fruiting plants |
Arricca Elin SanSone
Arricca Elin SanSone has written about health and lifestyle topics for Prevention, Country Living, Woman's Day, and more. She’s passionate about gardening, baking, reading, and spending time with the people and dogs she loves.
