Zinnias can be grown from seed that is sown early indoors and moved outside after a frost, or from potted plants or seeds sown directly in the ground after a frost.
Indoor Seed Sowing
- Utilizing a seed starting kit, sow indoors 5-7 weeks before to the date of outdoor planting in the spring.
- plant seeds A quarter-inch deep in seed starting solution
- At 70–75 degrees Fahrenheit, keep the soil moist.
- The seedlings appear in 7–10 days.
- As soon as seedlings appear, give them lots of light on a sunny windowsill or grow them 3–4 inches beneath 16–hour-per-day fluorescent plant lights that are off for eight hours at night. As the plants get taller, turn up the lights. Because they will become too hot, incandescent bulbs will not function in this process. Do not leave lights on continuously for 24 hours; most plants need a time of darkness to flourish.
- when they have two sets of leaves, thin to one seedling per cell.
- Seedlings don’t require a lot of fertilizer; feed them when they are 3–4 weeks old with a starter solution (half the strength of an indoor plant food), as directed by the manufacturer.
- After the first frost, transplant hardened-off seedlings into the garden.
- Seedling plants must be “hardened off” before being planted in the garden. By relocating young plants to a protected area outside for a week, you can acclimate them to outside circumstances. At first, be sure to shield them from the wind and the light. If frost is expected at night, cover or bring pots inside; then, in the morning, reintroduce them to the outdoors. The plant’s cell structure is toughened during the hardening off process, which also lessens transplant shock and scorching.
Direct Sowing in the Garden
- After any threat of frost has passed, direct-sow seeds in ordinary soil in full sunlight.
- The top 6 to 8 inches of soil should be cleared of weeds, and then it should be leveled and smoothed.
- The majority of plants do well in soils that have had organic matter added. Compost is a beautiful organic material that can be applied to your planting area whenever you like. It has the perfect pH level and nutrient balance. If compost is not available, topdress the soil with 1-2 inches of organic mulch after planting; this mulch will break down into compost over time. Following the growth season, a soil test will reveal what soil amendments are required.
- equally space the seeds 12 inches apart, then top with 1/4 inch of fine dirt.
- Lightly press the soil with your hand, water, and maintain a uniform moisture level.
- In 7–10 days, seedlings will start to show.
- When seedlings are 1-2 inches tall and 8–24 inches apart, depending on the variety, thin them.
Gardening: Planting
- Choose an area with good, rich, moist organic soil that receives direct sun.
- Turn the soil under to a depth of 8 inches to prepare the bed. To get rid of grass and stone clumps, level the area using a rake.
- For each plant, create a hole that is sufficiently large to hold the root ball.
- Set the top of the root ball so that it is level with the dirt around it. Up to the top of the root ball, cover with soil. Your hand should firmly push the earth down, leaving a small depression to hold water around the plant.
- Water deeply until a puddle appears in the saucer you have made. As a result, there is strong root-to-soil contact and the plants become established.
- Use the plant tag to indicate its location.
How to Grow
- Keep weeds under control while the plants are growing. Weeds compete with plants for water, space, and nutrients, therefore keep them in check by frequently cultivating or by using a mulch to stop the germination of their seeds.
- Mulches also support stable soil temperatures and moisture retention. Shredded leaves used as an organic mulch for annual plants give the bed a more natural appearance and, as they decompose over time, enrich the soil. Mulches should never be placed on a plant’s stems to avoid potential decay.
- During the growing season, make sure plants are well-watered, especially during dry spells. The growing season requires roughly 1 inch of rain every week for plants. To determine whether you need to add water, use a rain gauge. The optimum irrigation method is a drip or trickling system that releases water at low pressure directly into the soil. To reduce disease issues, water early in the day if you want to use overhead sprinklers so the foliage has time to dry before dusk. Maintain a moist but not saturated soil.
- Some protection from strong winds and intense sunlight may be required until plants grow established. Additionally essential is good airflow.
- A mild fertilizer can be administered after new growth starts to show. To prevent burn damage, keep granular fertilizers away from the plant’s top and leaves. Use moderate amounts of a slow-release fertilizer because greater amounts could promote root rots.
- Unless you are growing them purely for cut flowers and want long stems, pinch young plants to induce branching.
- To prolong plant flowering till fall, remove spent flower heads. Cutting zinnias fosters the emergence of fresh blooms and they make excellent cut flowers.
- Observe for illnesses and pests. For advice on pest management measures that are suitable for your area, contact your cooperative extension service.
- In order to prevent disease problems the next year, remove plants that have been killed by frost in the fall.
Growing Tips
- Zinnias can be arranged in tiny clusters alongside perennials or in mixed plantings with other summer annuals. They thrive in cottage and kid-friendly gardens, and cutting gardens frequently cultivate them.
- For containers, shorter zinnia cultivars are best. Be careful not to crowd them because the plants may grow taller and the blossoms may be much less than they should be. Never use garden soil instead of commercial potting mix, and make sure the containers have enough drainage. Plants growing in containers will need more water and fertilizer; keep an eye out for wilting or nutrient deficiencies.
- For cut flowers, trim stems before the blossom opens.
- Hummingbirds, butterflies, and beneficial insects are drawn to zinnias.
Common Disease Problems
Alternaria Leaf Spot: On the upper surface of the leaves and along the midrib, small, rounded, reddish-brown dots with white to gray centers appear. The lesions could surround the stems and result in wilt. Warm, rainy, or extremely humid conditions makes this sickness worse. Avoid getting water on the foliage, advises Burpee. Avoid working with moist plants and remove any contaminated plant components. Make sure there is lots of air movement. For advice on fungicides, get in touch with local cooperative extension service.
Aster Yellows: Plants grow excessively, become stunted, and develop witch’s brooms. Their petals also turn green and become malformed. Leafhoppers propagate this virus-like ailment. Burpee advises removing and destroying diseased plants. Eliminate leafhoppers. Eliminate any weeds in the area that the illness can also live on.
Bacterial Leaf Spot: The earliest symptoms are small, translucent spots with a wide, yellowish edge. Over time, these spots gradually get larger and develop an angular or irregularly circular shape with a reddish center. It flourishes in cooler climates. Flower heads may be impacted by the disease and become deformed. Burpee advises getting rid of diseased plants. Crop rotation should involve diverse family plants. Avoid watering from above. When plants are damp, stay away from them.
Botrytis: This fungus turns flowers, leaves, stalks, and buds a greyish color. It thrives in chilly, rainy weather. Burpee advises removing the damaged plant sections, avoiding watering at night, and not watering directly on the plant. Make sure plants receive adequate airflow. For advice on fungicides, get in touch with local cooperative extension service.
When the weather is humid, a fungus illness known as powdery mildew develops on the tops of the leaves. The surface of the leaves seems to be white or grayish, and they may curl. Burpee advises giving the plants adequate air circulation through optimum spacing and pruning in order to prevent powdery mildew. For advice on fungicides, get in touch with local cooperative extension service.
Common Pest and Cultural Problems
Aphids: These disease-transmitting sucking insects that feed on the undersides of leaves might be green, red, black, or peach in appearance. On the foliage, they deposit a sticky substance that draws ants. Burpee advises attracting or introducing aphid-eating predators like lady beetles and wasps into your garden. You can also use an insecticidal soap or a powerful spray to wash them away.
Leafhoppers: These insects damage leaves and retard growth. Moreover, they spread sickness. Burpee advises clearing up plant detritus. Use soaps with insecticides. For additional advice on insecticides, contact local cooperative extension service.
Burpee advises hand-picking Japanese beetles in the morning into a pail of soapy water.
Compared to what is typical for the variety, plants are shorter, and blossoms are much smaller: Overcrowding can cause zinnias to become stunted and produce smaller flowers. Always adhere to the spacing guidelines for each variety.
Spider mites: These minuscule insects, which resemble spiders, are approximately the size of a peppercorn. They can be yellow, brown, black, red, or black. They ingest plant liquids, sucking out chlorophyll and injecting poisons that leave the foliage with white spots. On the plant, webbing is frequently seen. They cause the leaf to stipple, dry, and become yellow. They proliferate swiftly and do best in dry environments. Burpee’s Advice Every other day, a strong spray can help control spider mites. Try using insecticidal soap or hot pepper wax. For advice on miticides, contact your local Cooperative Extension Service.
FAQ
Is it better to start my zinnias outside or inside? You can either start zinnias inside or outside, in the garden. You can get a head start by beginning them indoors if you have suitable indoor growth conditions, such as plant lights and a heat mat for germination. However, because zinnias are simple to grow from seed and bloom quickly, some gardeners may find that direct sowing is a superior alternative.
Is it possible to cultivate zinnias indoors? Zinnias may not thrive in many homes since they need full sun and high temperatures to develop effectively. In the summer, shorter varieties can be tested in a warm sunroom.
How should I take care of the cut zinnia flowers? When you cut your flowers in the garden, bring a pail of water with you, and as soon as you cut the flowers, immediately submerge them in the water. They will be able to absorb water through the newly sliced stem as a result. More surface area for the water to absorb when cut at an angle. Keep them away from the sun’s rays.
Do my zinnias need to be staked? Staking may be beneficial for taller kinds, especially if they are in a windy environment.
Why do my zinnias have much less flowers than I imagined and are tall and lean? Zinnias will grow tall plants and much smaller flowers if they are planted too near together. Always adhere to the planting instructions’ suggested spacing.
Before planting zinnia seeds, should I soak them?
If you’re raising zinnias from seed for the first time this year, you might still have some concerns. Here, I’ll address them for you.
How do you germinate zinnia seeds fast?
To hasten the germination of zinnia seeds, keep the seed trays warm. The biggest effect will be made by heated mats and a warm environment. Zinnia seeds can germinate in as little as five days when the soil is 70 to 75 degrees Fahrenheit, the ideal temperature for germination.
Should I soak zinnia seeds before planting?
Before sowing, zinnia seeds don’t require soaking. The seeds of zinnias are designed to sprout quickly when exposed to water since they are warm-season annual flowers that are indigenous to hot climates like Mexico and the southwest of the United States. The seeds only need to be sown and watered for germination to begin.
How long do zinnia seeds take to germinate?
The normal germination time for zinnias is 5 to 10 days. Seeds sown in trays with the soil kept warm at 70 to 75 degrees Fahrenheit using heat mats will germinate more quickly than seeds sown in cold soil, which could take up to three weeks.
Do zinnia seeds need light to germinate?
Zinnia seeds should be placed with 1/4 inch of dirt on top of them because they don’t require light to germinate. The seeds will require intense light in the form of a shop light or grow light as they begin to germinate and break the soil’s surface.
At what temperature do zinnias germinate?
Zinnia seeds should be germinated at 70 to 75 degrees Fahrenheit. The soil will reach these temperatures with the help of a heat mat put beneath the seed trays. In soil that is colder than 70 degrees, the seeds will still germinate, but it will take longer.
Do zinnia seeds need cold stratification?
Cold stratification, which involves chilling seeds prior to sowing, is not necessary for zinnias. The seeds of zinnias are designed to germinate without being exposed to cold because they are warm-season annuals that are native to hot climates.
When can I start indoor zinnia seedlings?
Zinnias (Zinnia elegans) are flowering annuals that offer summer color to a patio or garden. They have been a mainstay in the home garden for many years. Zinnia blooms can be grown in USDA hardiness zones 3 through 10, although they cannot withstand freezing. Before the final spring frost, plant zinnia seeds indoors to get a head start on your garden. When sown indoors, zinnias are simple to grow and should sprout within a week.
How much time does it take zinnia seeds to sprout?
One of the simplest flowers to plant, zinnias grow quickly and provide a lot of blooms. Additionally, they will continue to bloom right up until the first fall hard frost. Consider trying zinnia flowers this year to add a huge splash of color to your yard.
About Zinnias
Since zinnias are annuals, they will only produce blooms and seeds for one season before dying. The original plant will not reappear the following year. They are excellent for use as a cutting flower or as food for butterflies since they have vivid, solitary, daisy-like flowerheads on a single, tall stem.
Types of Zinnias
Zinnia elegans, the most widely grown zinnia species, has been developed to produce a large number of distinctive variants.
Single, semidouble, or double zinnia blooms are the three most common varieties. The number of petal rows and whether or not the flower’s center is visible serve to distinguish between these forms:
- A single row of petals and the center are both visible on single-flowered zinnias.
- Petal rows abound on double-flowered zinnias, and their centers are hidden.
- Between the two are semidouble-flowered zinnias, which have several rows of petals but discernible cores.
In addition to these shapes, zinnia flowers also occur in “beehive,” “button,” and “cactus” forms. Additionally, the plants themselves come in various heights: taller types function best as a garden bed’s background, while shorter varieties are useful as a border. There is a zinnia for every garden, in fact!
In an annual or mixed border garden, plant zinnias. Smaller zinnias work well as window boxes, edging, or in other containers.
To have a lot of flowers all season long, choose a place that receives full sun (6 to 8 hours of sunlight every day). Additionally, later in the season, foliar diseases like powdery mildew can be avoided by planting in an area with sufficient air circulation.
Although zinnias can grow in a variety of soil types, they prefer organically rich, well-draining soil. The optimal pH range for soil is between 5.5 and 7.5. The blooms will grow more quickly if compost (humus) is added to the soil. Find out more about soil improvements and getting the soil ready for planting.
When to Plant Zinnias
- Because they dislike being transplanted, it is advised that you start your zinnia plants from seed directly in the garden bed. If the correct circumstances are present, they will develop quite quickly from seed.
- It should be noted that zinnias can be grown from seed inside if you like. Just make sure to transfer them gently and young.
- Because zinnias are delicate to frost, wait to plant them until after the last frost in your area. See the frost dates in your area.
- Zinnias can tolerate daily temperatures as low as 60F (16C), although a range of 7484F (2328C) is ideal.
- To prolong the flowering time, sow a new crop of seeds every week or so for a few weeks.
How to Plant Zinnias
- Depending on the kind, place plants 4 to 24 inches apart. (Many common kinds are planted 2 feet between rows and 6 inches apart within the row.) For information about each variety, consult the seed packet’s back.
- Plant zinnia seeds no deeper than 1/4 inch.
- The majority of zinnia cultivars will produce seedlings in just 4 to 7 days, but it may take up to two months or more for blooms to appear (depending on planting site and climate).
- To promote air circulation, thin seedlings when they are three inches tall, spacing them 6 to 18 inches apart. As a result, powdery mildew is less likely to grow.
- To promote development and blossoms, keep the soil’s moisture level moderate and apply a mild fertilizer.
- Deadhead zinnias once they have finished blooming to facilitate the development of new blossoms.
- Since zinnias are annuals, they will perish with the first fall hard cold. Let the final blooms of the season fully mature before dispersing their seeds if you want them to reseed.
Zinnias still not your thing? In your garden, try them out for the following six reasons:
- With cultivars from the Dreamland Series, you can have a full-sized flower on a little plant. These zinnias are compact and dwarf, with stems that are 812 inches tall and totally double flowerheads that can be up to 4 inches across with a variety of colors.
- The dwarf, spreading cultivars of the Thumbelina Series have weather-resistant, solitary or semi-double flowerheads in a variety of hues. Their stems can reach a length of 6 inches, and their petals are 1-1/4″ wide.
- One of the largest and tallest of them all, the State Fair Series has huge, double flowerheads that measure 3 inches in diameter. Stems can reach a height of 30 inches.
- Typically, it takes zinnias 60 to 70 days from seed to flower (though it depends on conditions and variety). They are fantastic in a bunch of flowers!
- The tiny, narrow-leafed zinnias are great for hanging baskets and also make lovely dried flowers.
- Zinnias are considered to represent memories of those who have passed away. Discover more about the significance of flowers here.
- Zinnias may be harmed by bacterial wilt, powdery mildew, and bacterial and fungal spots. To prevent illness, keep leaves from getting too damp and correctly space your plants.
- Problems can also be brought on by caterpillars, mealybugs, and spider mites. Spraying should be avoided unless there is a real infestation because some leaf damage is not a problem.
- Thanks to their resistance to deer, zinnias may be able to prevent surrounding flowers from being eaten.