Zinnia Care In Pots: The Best Growing Guide

Bright perky hues and cheerful faces adorn easy to grow zinnia plants.  This popular annual thrives in full sun and brightens flower beds everywhere. But did you know that zinnias can grow in pots as well? 

Zinnias are a sun loving bloomer that produce many flowers from July until the first frosts of late fall.

pink zinnia flower petals with green stem

My children and I have happily grown zinnia flowers for years. Their colorful floral faces have smiled at us from raised beds, garden pathways, and patio containers. Zinnias really can grow anywhere sunny, but we love caring for them in pots on the patio the best.

Join us as we share how to grow and care for zinnia in pots. 

Benefits Of Growing Zinnia In Pots

I’m convinced you’ll love growing zinnias just as much as my family does. Here’s why:

  • They make fantastic cut flowers
  • SO much color to choose from: pink, orange, red, yellow, salmon and many shades thereof!
  • Zinnias attract bees and butterflies like crazy
  • They bloom all summer, from mid July to first frost
  • Zinnias are drought and heat tolerant and can grow in hot places
  • They are easy to grow in containers, pots and flower boxes!

Learn how to grow snapdragons in pots here.

How Do You Take Care Of Potted Zinnias?

To grow and care for zinnia in pots, you can either plant starts from a garden center or purchase zinnia seeds and grow your own seedlings.

Choose a pot with drainage holes and fill it with potting soil. Plant your young zinnia flowers in the pot and water well at the base of the plant. 

Give your zinnias a very sunny spot in which to grow. Water regularly, letting the soil dry out in between. As they bloom, deadhead the flowers regularly to encourage more flowering!

Keep reading for the best tips for growing zinnias in containers!

Tips For Growing Zinnias In Pots

Here are the best tips for growing potted zinnias:

Choose The Right Zinnia Variety

Zinnias make excellent container plants, but you want to choose the right type of zinnia for your pot.

Taller varieties can grow up to 48 inches and are not best suited for small pots and containers. These tall zinnias grow well in raised beds and flower beds and are often planted alongside a vegetable garden to attract pollinators.

Shorter dwarf zinnia varieties are a great choice for containers. They come in many colors, shapes, and heights!

If you aren’t sure what variety of zinnias you have, check the back of the seed packet for growing information, or the label on a zinnia start.

We recommend these shorter varieties for pots and containers: 

Thumbelina Dwarf Zinnia These bright and cheerful zinnias grow just 4 to 6 inches high

Lilliput Salmon Beautiful pink dwarf zinnias that will make a bold splash on the front porch

Button Box Mix This colorful mix grows up to 10 inches tall and has a variety of bold color

Keep in mind that if you have large containers, such as feed troughs, to plant in, tall zinnia varieties can thrive! In order to keep taller growing zinnia varieties from toppling over, increase container size.

How To Grow From Seeds

Growing zinnias from seed is incredibly easy. In fact, you can purchase a seed packet and plant them directly into the potting soil of your container, if desired.

Make sure all danger of frost has past before doing this outside (or start them inside). Check your growing zone and last frost date for information regarding your local growing climate.

Zinnia seeds are medium sized black rectangles and need to be planted only about 1/4 inch deep. When watering zinnia seeds, be careful not to splash the seeds out of the soil.

Plant several seeds in each hole. As the zinnia seedlings emerge you can cut the weaker seedlings at the base.

If you have one handy, you can use a spray bottle to soak the soil. Keep the soil wet while the seeds germinate.

Purchasing Starts

Zinnia starts can be purchased from gardening centers and big box stores.  In late spring you will see friendly zinnia plants waving from any store that sells plants.

Zinnia starts are usually 3 to 4 inches tall. Look for healthy, well-watered plants that do not show any sign of disease.  Steer clear of plants with yellow, wilting leaves, spots, or a weak looking plant. The leaves and stem should be bright green and the plant look firm and strong. 

Purchase zinnia starts in spring after all danger of frost has passed.

bright red zinnia flower with green leaves and stem

How To Choose A Container

The good news: zinnias can be grown in any kind of container. Terra cotta pots, cedar containers, plastic and concrete containers will work well. 

The container should be at least 12 inches in diameter and 12-18 inches in depth. Size up from there for larger plants.

Any container chosen should have drainage holes in the bottom of the pot for excess water to flow through. You do not want the soil to become water logged as this can encourage the growth of disease. 

Container size will vary based on how many plants you are going to add and what variety you are growing.

Air Circulation

As you get ready to plant your zinnias, make sure to take air flow into consideration. Properly spacing zinnia plants will prevent disease from forming. Air circulation in between other flowers will help prevent disease and also allow each plant to get the water and nutrients they need to thrive.

That doesn’t mean you can’t plant your flowers close together, however avoid over crowding them.

Soil Needs

Zinnia plants need a loose, well-draining potting soil. Do not use soil from the garden or garden bed specific soil as these soils will not drain well and will compact within the container. 

You can mix organic matter such as decayed leaves at the bottom of the container to help with draining and add extra nutrients. ­­

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Sunlight

Remember that zinnias are heat and sun loving!

Zinnias crave full sun, at least 6 hours of direct sunlight. Place your zinnia containers on a sunny patio. Late afternoon shade is fine, as long as they are getting full sun the rest of the day.   Proper sunlight will promote blooming and keep the plant dry, warding off fungal infections and disease. 

If a zinnia flower is not planted in enough sun it can become leggy, which means the plant will grow and stretch trying to find sunlight. It will also fail to produce bountiful blooms.

red and yellow zinnias growing together

Watering Zinnias In pots

Deeply water zinnia flowers in pots, then let the soil dry out before the next drink.

Proper watering technique will help prevent disease and fungal infections, as well as allow the zinnia to thrive. Avoid overhead watering, and instead water at the base of the plant. This will help prevent water from sitting on the leaves, which can encourage disease.

Overhead watering can encourage fungal problems like powdery mildew. 

Wait until the soil is dry to water, but keep a close eye on zinnias in pots. All flowers in containers tend to dry out faster than plants in the ground!

How To Plant Zinnias From The Nursery

We thought it would be helpful to share a few tips on the best methods for planting your zinnia flowers purchased from a plant nursery:

  • You will need potting mix, a container, bone meal, water, and zinnia plants.
  • To plant zinnias from starts, gently remove the young plant from the plastic container and loosen the roots of the plant with your fingers. Dig a hole just a few inches deep and add a teaspoon of bone meal in the bottom of the hole. Place zinnia plant in hole and cover with soil. 
  • The size of hole you dig will depend on the size of your zinnia plant and its root system. The top of the zinnia plant should be level with the soil, not below it or above it. 
  • Regular watering of newly planted zinnias is important. Water more frequently when the plants are trying to get established!

Bone meal is a great all purpose fertilizer that we mix into the soil when planting most flowers.

Bone meal helps strong roots to grow and a robust plant to develop, and contributes to beautiful blooms. Mixing it into the soil results in a steady delivery of nutrients through the root system!

Fertilizing

Zinnias do not need much fertilizing. They thrive on their own if given the proper soil and sunlight in which to grow.

You can use a balanced flower fertilizer when plants are established if you want to give them a boost.

Deadheading Zinnias In Pots

Did you know that zinnias can bloom all summer long and well into fall? If you properly deadhead zinnias they will produce new flowers the entire summer growing season. 

To deadhead spent flowers, follow the top of the flower down to the first set of leaves. Cut the stem of the zinnia flower here. 

If you only cut the flower head off, the zinnia plant will not be stimulated to produce new flower blooms. 

Regularly deadheading zinnias will also keep the plant healthier. 

During the late summer months when the flower is blooming regularly we recommend checking for spent flowers every few days. Consistently deadheading will promote regular growth of new blooms.

Read our article on how to plant and deadhead zinnias for blooms all summer here.

red zinnias with green leaves

Diseases

There are several diseases that can plague zinnias. Powdery mildew, bacterial leaf spot, alternia leaf spot, bacterial wilt, and fungal spots. 

Disease can be caused by excess moisture and excess water. Fungus and bacteria thrive in moist, warm environments. Zinnia can be particularly susceptible to these diseases during wet summers. 

Air circulation is also import in preventing disease, which is why it is important not to over crowd your plants. 

Removed diseased parts of the plant immediately with a clean pair of clippers and dispose of them far away from the zinnia plants.

Pests

Japanese beetles

Japenese beetles can wreck havoc on a zinnia plant. They enjoy munching the leaves and flowers, but the good news is they are easy to get rid of. You can remove Japanese beetles and drown or squash them, or use Neem oil to spray your flowers.

Some people have claimed to have good success removing beetles with a dish soap and water solution, then spraying the leaves, petals and stems of the plant.

*We have grown zinnias for years and found them to be an easy to maintain, low maintenance plant for the flower garden. Keep your eye out for pest and disease, but zinnias tend to be low maintenance.

red and yellow zinnia flowers growing in a pot

Frequently Asked Questions

Can Zinnias Grow In Part Shade?

Zinnia flowers really love and crave full sun, even all day summer sunlight! Zinnias can be grown in a location that gets afternoon shade, however they may not bloom as prolifically as when basking in the sun.

How Long Do Zinnias Last In Pots?


Zinnias will thrive in pots all summer long and into fall, up until the first frost. Keep them healthy with deep, regular watering (letting them dry out between drinks), consistent deadheading and full sunlight.

How Do I get More Blooms On My Zinnias?

Zinnias love to produce abundant flowers! They are a cut and come flower, which means the more you “cut” the more they will bloom. Deadhead flowers at the base of the flower stalk, before a set of new leaves to promote more flower growth.

Why Are My Potted Zinnias Dying?

Potted zinnias may be dying if they do not have enough sunlight, or are over watered or under watered. If you used garden soil or compact soil in the pot the roots of the plant will not be able to thrive and receive water and nutrients.

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2 Comments

  1. Thank you for your expertise!!! I love reading and learning from you. You give me so much pleasure and confidence. I appreciate you so much!! Xox

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