Annual Plants With Purple Flowers

If you want a garden full of color without a long-term commitment, look no further. Annual plants with purple flowers are the perfect solution, offering easy to grow purple blooms that fill your beds and containers with vibrant life in just one season.

These plants grow, flower, and set seed all in the same year. This means you get fast results and can change your garden’s look every spring. Purple flowers add a touch of royalty, calm, and depth to any outdoor space, and they attract helpful pollinators like bees and butterflies.

Let’s look at how to choose, plant, and care for these stunning plants.

This group includes a wide range of shapes, sizes, and shades. From deep violet to soft lavender, there’s an annual purple flower for every garden style. The best part is their simplicity—they’re generally low-maintenance and reward you with constant color.

Top Picks for Easy Purple Annuals

Here are some of the most reliable and beautiful choices. You can find these at most garden centers in the spring.

Petunias: A classic favorite. They spill beautifully over containers and bloom non-stop if you give them sun. Look for ‘Purple Wave’ or ‘Supertunia Vista Bubblegum’ for a real show.
Salvia (Victoria): This plant sends up spikes of deep purple flowers. It’s heat-tolerant, drought-resistant, and loved by hummingbirds. It’s a real workhorse in the summer garden.
Heliotrope: Known for its incredible vanilla-like fragrance. The rich purple clusters are a sensory delight. It prefers rich soil and regular water.
Lobelia (Trailing): Perfect for adding a cascade of tiny purple flowers to window boxes or the edges of pots. It prefers cooler weather and can fade in peak summer heat, but often rebounds in fall.
Verbena: Tough and spreading, verbena creates a carpet of small purple clusters. It handles heat and dry spells very well once established.
Angelonia (Summer Snapdragon): Its spiky flowers add great texture. It thrives in hot, humid weather and doesn’t need deadheading, which makes it super easy.
Ageratum (Floss Flower): These fluffy, powder-puff flowers come in soft lavender shades. They’re great for edging and have a long blooming period.
Ornamental Millet ‘Purple Baron’: Adds dramatic height and foliage. The deep purple-burgundy leaves and corn-like heads offer great structure.

How to Plant for Success

Getting your annuals off to a good start is simple. Follow these steps for the best results.

Wait for the Right Time: Don’t plant too early. Wait until after the last expected frost in your area. Tender annuals can be damaged by cold nights.
Choose a Sunny Spot: Most annuals that flower prolifically need full sun. That means at least 6 to 8 hours of direct sunlight per day. Some, like lobelia, can tolerate part shade.
Prepare the Soil: Work some compost or aged manure into your garden bed. For pots, use a high-quality potting mix, not garden soil. Good soil means healthier roots and better blooms.
Plant Properly: Gently loosen the roots if they’re pot-bound. Dig a hole slightly larger than the root ball, place the plant in, and fill in with soil. Pat it down gently and water thouroughly.
Space Them Out: Check the plant tag for spacing recommendations. Crowded plants compete for light and air, which can lead to disease.

Watering and Feeding Basics

Annuals grow quickly, so they need consistent resources. The goal is to keep them evenly moist, not sopping wet or bone dry.

Water deeply at the base of the plant in the morning. This allows foliage to dry, reducing fungal disease risk.
Containers dry out faster than garden beds, so check them daily in hot weather.
Feed your plants regularly. Use a balanced, water-soluble fertilizer every two weeks, or mix a slow-release fertilizer into the soil at planting time. This fuels all those flowers.

Keeping the Blooms Coming

The secret to non-stop color is simple maintenance. A little effort goes a long way.

Deadheading is the most important task. This means removing faded or spent flowers. When you do this, the plant doesn’t waste energy making seeds. Instead, it puts its energy into producing more flowers. Just pinch or snip the old flower off right below the bloom.

For plants like petunias that can get leggy, don’t be afraid to give them a trim. Cut back about a third of the growth in mid-summer. They will bounce back bushier and with a fresh flush of blooms.

Keep an eye out for pests like aphids. A strong spray of water from the hose is often enough to dislodge them. Good air flow between plants also helps prevent mildew and other issues.

Design Ideas for Purple Blooms

Purple is incredibly versatile in the garden. Here are some ways to use it effectively.

Monochromatic Magic: Plant different shades and textures of purple together. Combine spiky salvia with mounding petunias and trailing verbena for a sophisticated, cohesive look.
Complementary Contrast: Pair purple with its opposite on the color wheel: yellow or orange. Purple marigolds with yellow marigolds, or orange zinnias with purple ageratum, create vibrant, eye-catching combinations.
Cool and Calming: Mix purple with white and silver foliage plants, like dusty miller or sweet alyssum. This scheme feels elegant and serene, perfect for evening gardens.
Vertical Interest: Use taller purple annuals, like angelonia or ornamental millet, in the center or back of a border. Place medium and trailing plants in front to create layers.

Growing from Seed vs. Buying Plants

You have two main options for getting your annuals. Each has its benefits.

Buying starter plants from a nursery is the easiest and fastest route. You get a head start on the season and can see the color before you buy. This is ideal for beginners.

Growing from seed is more economical, especially if you need lots of plants. It also offers a wider variety of choices. Some easy annuals to start from seed directly in the garden include:

Cosmos
Zinnias
Sunflowers (some varieties)
Bachelor’s Buttons

For a longer head start, you can sow seeds indoors 6-8 weeks before the last frost. You’ll need seed trays, a grow light, and some patience, but it’s very rewarding to watch them grow from scratch.

Seasonal Care Through Summer and Fall

Your annuals will change with the seasons. A little ajustment in care keeps them looking good.

In the peak summer heat, watering becomes critical. Mulch around your garden plants with a layer of shredded bark or compost. This helps the soil retain moisture and keeps roots cooler. Container plants may need watering twice a day during heatwaves.

As fall approaches, many annuals will slow down after the first light frost. You can pull them out and compost them. Some, like petunias, might keep blooming until a hard freeze. If you want to save seeds from heirloom varieties, let a few flowers dry on the plant and collect the seed pods.

FAQ About Purple Flowering Annuals

What are the best annual plants with purple flowers for full sun?
Petunias, salvia, verbena, angelonia, and heliotrope are all excellent choices that thrive in full, direct sunlight.

Which purple annuals do well in shade or part shade?
Lobelia, browallia, and torenia (wishbone flower) can perform well in areas with less direct sun, like partial shade.

Are there any purple annual flowers that are also fragrant?
Yes! Heliotrope is famous for its sweet, vanilla-like scent. Some petunia varieties also have a light, pleasant fragrance, especially in the evening.

How often should I fertilize my annual flowers?
For continuous blooms, feed them every 10 to 14 days with a water-soluble fertilizer, or use a slow-release fertilizer at planting time as directed on the label.

Can I save seeds from my annual plants with purple flowers for next year?
You can for heirloom or open-pollinated varieties. Hybrid seeds often won’t come true to the parent plant. Let the seed heads dry on the plant, then collect and store them in a cool, dry place over winter.

Adding annual plants with purple flowers to your garden is a simple way to guarantee a season of beauty. With minimal effort, these easy to grow purple blooms provide maximum impact. Choose the varieties you love, give them a good start with sun and good soil, and enjoy the colorful show from spring right through to fall. Your garden—and the pollinators—will thank you for it.