You may need to fertilize annual flowers more than you think– but not veggies!

row of hanging baskets in West Seneca New York
Photo by Connie Oswald Stofko
orange calibrachoa in West Seneca New York
Calibrachoa is also called million bells. Photo by Connie Oswald Stofko

by Connie Oswald Stofko

Contrary to what many gardeners believe, fertilizing your annuals won’t cause them to “bloom out” or be done blooming before the summer is over, said Jen Weber, retail manager at Mike Weber Greenhouses, 42 French Rd., West Seneca.

“It’s just the opposite,” Weber said. “Without the fertilizer, your plants won’t reach their potential. They’ll be smaller, thinner, weaker, leggier-looking plants.”

In the case of petunias, verbena and calibrachoa (million bells), they will become leggy, won’t bloom as heavily and may even turn a yellowish color.

verbena and petunia flowers
The large purple flowers are petunias and the small white and purple flowers are verbena. Photo by Connie Oswald Stofko

“Petunias, verbena, and calibrachoa need fertilizer every time you water!” Weber said. “Yes, that is correct. Every time.”

Geraniums need to be fertilized three times a week.

Begonias, every other week.

All other annual flowers need to be fertilized at least once, if not twice a week.

You should fertilize those annuals whether they are planted in a pot or in a garden bed, Weber said.

The flowering plants that we refer to as ornamental annuals are generally from equatorial regions in South America or Africa. Those regions have different soils, and you need fertilizer to have the plants perform well in our area, Weber said.

Make sure you follow the directions on the fertilizer. Depending on what you buy, it may call for you to add one tablespoon of granules to a gallon of water. Pour the liquid fertilizer onto the soil over the roots of the plant. Don’t overfertilize.

If you apply the fertilizer correctly, you shouldn’t have to worry about contaminating our water supply, Weber said. You will be using only a small amount of fertilizer, and the plant should take up the nutrients.

She noted that she grew up with well water, and her well was 90 feet deep. Other people she knows in the area have wells that are 200 or 300 feet deep. If you use fertilizer correctly, you shouldn’t have runoff that gets into groundwater, Weber said.

Don’t fertilize perennials and vegetables so much

Flowering perennials planted in garden beds will do well in soil that is rich in compost, she said, adding that composted manure is the best thing for your garden. You don’t need to fertilize those flowers the way you need to fertilize the annual flowers.

Vegetables, especially tomatoes, shouldn’t be fertilized after they have flowered. If you fertilize them after they have flowered, you’ll get big, beautiful plants with no fruit, she explained. See more on caring for tomatoes here.










6 Comments on “You may need to fertilize annual flowers more than you think– but not veggies!

  1. I’m being told not to fertilize in the fall. Many of my plants are annuals and are planted in containers. I also have hardy ferns and hardy banana trees in containers. Shouldn’t I continue to feed these?

  2. Jillian, I’m glad you found this post helpful! Did you know you can subscribe to It’s free! When you subscribe, you get an email every Tuesday to tell you there is fresh content. Tell your gardening friends!

  3. I wondered why my hanging petunia baskets planted from 6 packs were so disappointing in bloom production. Fish emulsion was not doing it ! Now I need to decide which fertilizer to buy.
    Thank you !

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