Zinnias are among the classiest and best-loved household flowers and can help beautify nearly any garden.
They are remarkably easy to grow in pots and keep indoors.
In this article- We’ll cover a step-wise detailed method for you to understand the proper way to grow zinnias in pots to help you beautify your indoor space with these lovely colored flowers.
What’s the Best Time to Grow Zinnias?
Although zinnias are relatively simple to cultivate, planning is important to make a success of it.
Zinnia plants need a full year to complete their growth cycle.
This means you’ll want to start the process early.
You can begin growing these plants approximately 4-6 weeks before the last spring frost arrives.
In addition, a few weeks while keeping the pots indoors prior to taking the pots outdoors after the spring season has begun will give you enough time to tend to the zinnia seedlings develop before you take them outdoors.
If you want to complete this process outdoors, you will have to wait for all the dangers of frost to be entirely gone.
They will grow if it is approximately 60 degrees Fahrenheit outdoors, but they do best during warmer weather. The ideal temperature range is 75-85 degrees Fahrenheit.
Step by Step Method to Grow Zinnias in Pots
Again, zinnias are easy to grow in pots, but they require the right technique and careful attention to many details.
Following the simple instructions outlined below will give you the opportunity to sow and grow these flowers in pots.
Step 1: Choose the Correct Zinnias Type
Although you can plant and grow almost all types of zinnias in pots, using hybrid and short varieties is the safest choice.
These types include:
- Sollecito cultivars
- raspberry lemonade mix
- star orange
- and zahara
Step 2: Choose Pots Wisely
Selecting suitable pots for zinnia plants is critical.
While you can always use smaller pots, if you really want your zinnias to thrive, go with a pot that is at least six inches across when planted alone.
There are also lighter-colored pots made from durable plastic that can be used in place of ceramic pots. If you want two or three plants planted together, you will need a pot at least 10 inches across.
Then there’s the drainage factor to consider when determining a pot for your plants.
Always purchase pots with sufficient drainage holes at the bottom. This way, any excess water has an easy escape route. You do not want soils that stay soggy for these plants.
Important to remember – If you use old pots that you have used for other plants, consider sterilizing them. If you sterilize used pots, it eliminates any rogue fungal spores or diseases that may potentially transfer to your zinnias.
Step 3: Select the Right Soil
In order to have zinnias thrive, you want to add nutrient-rich and well-draining soil to the pots in which you plan to plant them.
If you are working with garden soil already, you may consider adding peat moss and perlite, along with some compost.
This should make the soil nutrient-rich and add drainage.
You should consider also getting the pH of your soil checked by a local garden center or nursery, and ideally it should be 5.5 to 7.5 range for growth.
Step 4: Start Planting Zinnias
Zinnias differ from mediocre floral plants because they can be grown from seeds.
They will also grow seeds for the next season/next year for propagating zinnias.
Select a warm place to place the pots for easy germination. A temperature range of 75 to 85 degrees Fahrenheit is sufficient.
Once you have placed the pots in the proper location, you can plant a few seeds in the middle of them.
After that, cover each seed with a quarter to half an inch of soil and spray some water on top of the soil.
After about a week, you will notice the seeds popping through the soil and sprouting.
You must keep the soil moist all the time so that the zinnia seeds will develop properly.
Do not forget – if you have a pot for a matter of fact of a single plant, you will need to thin the seedling once they get to be about three to four inches tall.
Select the healthiest and strongest looking seedling to keep and remove the rest from the pot. You will need to wait about five to six weeks or so and then move the pots outdoors if you want.
If you want to plant the seedlings directly, you will need to wait for temperatures to become warmer, without looking back on. Then, you will have to simply plant them outdoors.
Step 5: Ensure Proper Care
After you have seeded or planted your zinnias, it is time to care for them appropriately to help the zinnias remain healthy.
To provide adequate care for your zinnias, remember:
Water Plants Timely
Water is essential when it comes to growing zinnias – and they need lots of it!
Remember, they are super thirsty, and you’ll want to keep the soil constantly moist.
That’s not to say that you should over-water them!
Over-watering will create root rot issues and fungal problems that can stunt zinnia growth.
In general – you will want to give your zinnia pots about one inch of water every four to seven days depending on your area’s weather conditions.
If you live in an area that becomes very hot, you may need to water the plant a little more often.
Be sure to apply the water to the soil –never the stem, leaves or flowers! Watering the zinnia in this manner opens the door for fungal spores.
Provide Sufficient Sunlight
You will want to locate your zinnia pots where they are getting direct sunlight for at least six hours each day.
Otherwise, you will see little to no blossoms, little to no growth, and a decline in plant health.
It will also put your zinnias at a much greater risk for different plant diseases that could kill your zinnias.
If you are keeping the zinnias indoors, you will want to put them on a south-facing windowsill.
This will help to make sure they get enough good light throughout the day.
Ensure Good Air Circulation
A fungal infection is one of the most common issues many gardeners face when growing zinnias.
Usually, this happens because of poor air circulation that prevents excess water from evaporating from the soil.
Make sure you do not plant your zinnia plants close to one another. Make sure the pots are spaced enough apart to create room for each plant to breathe.
This is especially true if you can not provide the plants with sunshine for at least sixth day.
Good air circulation will allow for excess water to evaporate easily, and it will also keep the soil from becoming soggy.
Fertilize Zinnias
Zinnia plants can receive considerable advantages when fertilizing. Fertilization ensures the proper growth and the plants will produce flowers that are bright, vivid colors.
However, you will want to use a light fertilizer because these plants grow quicker than other flowers. Zinnias are very productive and if you use too much fertilizer, you will overproduce the plants.
Use a water-soluble fertilizer that is low in potassium and nitrogen, and high in phosphorus. This will allow zinnias to convert all of the nutrients available into usable energy.
The fertilizer will benefit the young zinnia plants the most. Therefore, be sure to fertilize them when they are about four to five inches tall, and you apply a light fertilizer.
You can also fertilize again at the mid or later portion of the summer season, so the zinnias can benefit from the additional energy and nutrient boost to continue flowering!
Control Pest and Disease
Common pests present in garden areas can cause damage to zinnias and their blooms and foliage.
You can easily fix this by spraying neem oil around the plants.
Avoid wetting the stems and foliage of your zinnias, as wet foliage can cause bacterial wilt, powdery mildew, and fungal spots.
Step 6: Prune Zinnia Plants
Zinnias are annuals, meaning they will die after a year and only return if self-seeded or you buy seeds or seedlings to grow.
That means you do not have to worry about pruning these plants.
You can do some pruning, though, and pruning may help you manage how the plant is using energy.
Deadheading is the easiest way to prune zinnia plants.
Deadheading is when you prune flowers from the plant that already died.
You will need to wait until a flower wilts after blooming and then cut the bud when the flower is just about to fall off.
This is a great way to extend the length of flowering and warn that the plant will produce new flowers. You can also use deadheading to make your zinnias look cleaner and neater.
Just a note – Pruning will also allow you to change the way a tall zinnia plant will grow. When the plant is still small, you can pinch back the tip of the plant to prevent it from getting too tall.
That way, the plant will use the same available nutrients to grow more side branches and look better.
How Much Zinnia Plants Take to Bloom?
As stated previously, zinnia seeds germinate in about a week.
These plants mature rather quickly — typically a couple of months from germination until they’re blooming.
Zinnias will continue to flower in bright colors until the autumn (or until the first frost). Zinnias can grow in USDA hardiness zone 3 to 10.
Can Zinnias Self Seed?
Zinnia plants begin seed production instantly once the flowers start to drop off and fade.
Keep in mind – deadheading will allow the plants to produce additional flowers but can cause issues with seed production.
Seeds drop off from dying flowers and on to the ground, where they germinate in spring and grow into new zinnia plants as it warms up.
Include seeds from the strongest flowers with the best color into an envelope. Place this envelope in an airtight glass jar and store it in a dry, dark, cool spot out of the sunlight.
Then after the next season – You can always apply the same method spoken about in this guide to growing zinnia plants in pots.
How Do You Transplant Zinnia Seedling?
When you’re at a nursery or garden center to buy zinnia plants, make sure that you purchase the bushiest ones.
Look for plants that are not lanky and tall, as they will be weak growers.
Also, inspect the plants for any possible pests or problems such as fungal infection.
You want to make sure that the plant has dark green leaves without curled edges, white patches, or holes.
Now that you have zinnia plants, consider the steps below as a guide to your safest methods for transplanting it:
- Fill the pot you will use for your new plant with well-drained, nutrient-rich soil.
- Remove some soil from the top, allowing enough room for the new plant’s bottom to go a little higher than the soil surface.
- With your dominant hand, hold the seedling from the bottom of its stem.
- While doing this, flip the pot upside down and pull the seedling gently. You may have to tap the bottom of the pot a couple of times.
- After you have removed the seedling from the pot, remove excess soil at the bottom of the plant and calmly place the plant inside the pot you were preparing.
- You should add some more soil around the base of the seedling to secure the plant in place.
- After this, you will water the soil until its moist and place the pot where it gets direct sunlight.
We suggest you put your new seedling in a different place for at least seven to 10 days after you bring them home.
This way, you can check to ensure the seedling is pest and disease free. Also, if the new zinnia seedling is infected, you’ll protect the rest of your plants.
Final Words
Growing zinnia plants in containers is a straightforward undertaking.
You only need to ensure that you select the appropriate pot size and soil type, and that you keep your plant in a well-ventilated area that gets plenty of sunlight.
Make sure to keep the soil moist, and keep pests and pathogens away from your zinnia plants.
Within a couple of months, the plants will flower and add more beauty and character to your home with their colorful flowers.