How to Care for Annual Flowers

Annual flowers require a little TLC to remain lush and vibrant throughout the season. From deadheading and pinching to fertilizing and watering, giving these beautiful blossoms a bit of ongoing attention can go a long way toward ensuring continual color in your garden or landscape. 

While your best bet remains consulting with a professional landscape design and maintenance firm for floral upkeep, there are certain helpful hints all homeowners can follow day-to-day. 


Deadheading is the process by which spent blooms are removed from plants, along with any developing seeds. By “tricking” the plant, in effect, seed production is temporarily paused, facilitating new flower growth.

The simplest method is to pinch off just below the base of the spent flower. This process will never harm the plants, and may be repeated as many times as needed throughout the season up until the first frost. 

Some annuals may also benefit from a more drastic pruning, typically around midsummer. Plants such as petunias, verbena and million bells benefit greatly from this seasonal shearing, and will generally regenerate in about two to three weeks with a second peak of blooms



Many annuals are used to more tropical climates, and so are hungry for plant nutrients. Fertilizer applied at the start of season may run its course by midsummer, necessitating reapplication. Early season (April to May) bed prep is key, and compost can often aid in the process of maintaining nutrients throughout the summer months.

Slow-release, or control-release, fertilizer is ideal, as it disperses over the course of the growing season. Liquid fertilizers offer another option for the more hands-on gardener, and can be applied regularly throughout said growing season. Be sure to follow the package directions for instructions on frequency and rate of application.



When it comes to watering, deep, infrequent hydration is preferable to more frequent, lighter approaches. This is of course also dependent upon the levels of natural rainfall, soil type, and exposure. Typically, one to two inches of water per week is sufficient, applied earlier in the day to give the ground ample opportunity to dry before nightfall, thus limiting the potential for disease. 

Keep in mind, this is only true for annuals that are planted directly in the garden. Hanging baskets and planters should be checked daily, as they can dry out more quickly. Remember, the dog days of summer are still ahead, and dry, drought-like conditions are not unusual in July and August on Long Island.



Mulching can be helpful in conserving moisture, minimizing weed growth, and maintaining soil temperature. Two to three inches of mulch is all that’s required to get the job done. Should weeding become necessary, it’s imperative that it be done on an ongoing basis, as weeds will quickly compete for space, moisture and nutrients, leaving annuals starved for these essentials. 

Should your annual blossoms surge in size by late summer, it may become necessary to reinforce them by using some type of support, stake, or fencing grid to prevent toppling. Dahlias and mandevillas are prime candidates for staking. 


For further information on ongoing annual planting care, contact Dodds & Eder today