Take the guesswork out of buying fertilizer by selecting one especially formulated to meet the needs of a particular group of plants. Here are some plants that often have a fertilizer created to meet their specific needs.

Flowers need plenty of phosphorus, so the middle number in a good flower fertilizer is at least as high as the first number (nitrogen), or maybe higher. Plants that bloom for a long time and use lots of water may need an extra feeding in during their growing season. See Garden for the fertilizer preferences of many popular flowers.

Lawns need lots of nitrogen because they are constantly producing new green leaves. See Lawns for descriptions of the most widely used lawn grasses and information on how and when to fertilize them.

Roses need more fertilizer than many other shrubs or landscape plants to support steady growth and blooming. The best fertilizer for roses contains a unique allotment of nitrogen, phosphorus, and potassium to support growth and many blossoms throughout the entire growing season. See Roses for more about feeding roses.

Azaleas, camellias, and rhododendrons and other shrubs that need acidic soil will appreciate a fertilizer that contains added iron, sulfur, and magnesium to maintain a deep green leaf color. Other plants that have similar needs, such as blueberries and mountain laurel, appreciate the same type of fertilizer. See Trees and Shrubs for more about feeding azaleas, camellias, and rhododendrons.

Vegetables are fast-growing annuals, so they do best with a fertilizer that contains all three primary nutrients. Look for fertilizers that contain timed-release nitrogen to save time and to be sure your vegetables receive a steady supply of nutrients. Interrupted water or feeding can reduce your harvest. See Vegetables for more about fertilizing vegetables.