12 Best Flower Fertilizers for Growing Gorgeous Blooms

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.

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, potted plants, trees, and shrubs. Plus, it's safe for pets!

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.

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.

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.

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.

This fertilizer has a NPK 2-3-1 ratio and is made from fish and seaweed to give your flowers (and veggies, fruit, and grass!) 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.

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!

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.

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 great for indoor and outdoor flowers, as well as veggies, fruit, trees, and shrubs.

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.

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.