Zinnias tolerate heat and are easy to take care of, not to mention the brilliant colours they put on display every summer. They are grown as perennials but are most times grown as annuals.
Unlike other perennials which take time to grow, their seeds grow fast, sprouting in days and reaching full bloom in a matter of weeks.
How much water do zinnias need? This is the right place to find out!
Zinnia flowers can come in singles, with petals lined up in one row around an open centre, or doubles, in two rows. For colouring, petals can have two, three or multiple colours, making zinnias a truly captivating bloom.
Plant zinnias in spots where you want to add a touch of colour.
When And Where To Plant Zinnias
Zinnias grow and produce many flowers when planted in full sun. In hot climates, they can also put out flowers in partial shade, however, they will be more exposed to sickness and put on fewer flowers.
The soil type that these lovely flowers develop in is fertile, well-drained soil with plenty of organic matter. Soil that doesn’t hold moisture for long is vital because zinnia seedlings may be subject to rot in cool, moist soils.
Plant zinnia seeds directly into the soil in spring when the risk of frost has passed. If you desire for your zinnias to bloom earlier, plant the seeds indoors 4 to 6 weeks before your final frost date.
Zinnia seeds should be sown some inches apart in rows or columns. Narrow their number down to 8 to 18 inches apart, depending on the variety, as soon as the plant has grown 4 or 5 leaves.
How To Grow Zinnias Throughout The Season
Zinnias come in a variety of plant sizes. While some are low-growing plants up to 1 foot tall with a creeping growth habit, others are 3-foot tall plants with large flowers. Plant the right variety for your use and space.
Creeping or trailing varieties have smaller buds and produce more decorative flowers but the larger varieties are often used for vases and are best grown in rows or groups for a better aesthetic effect.
Zinnias have long and firm stems, so no staking or support of any kind is required. The soil should be enhanced before planting with compost and as soon as the flowers appear, apply an organic fertilizer with equal parts of nitrogen, phosphorus and potassium to get more buds and bigger flower sizes.
If you want your tall zinnias to be shorter and leafier, pinch back the growing top of the plant when it is still young. More side branches will be forced to form, producing a shorter plant and more buds.
However, it may delay flowering, especially in cool summer areas.
Irrigation At Time Of Planting
Most zinnia plants are grown from seed either by sowing them directly into the ground or by planting them in containers and trays before transplanting them at a later date. If you plant the seeds in a tray or pot, sow the seed ¼ inch below the soil surface, then water the soil lightly to moisten it to a depth of about 1 inch.
Now, cover the pot or tray with plastic wrap to seal in the moisture and keep the soil moist. On the other hand, when sowing zinnia seeds directly outdoors, a plastic cover is not an option.
Instead, you should therefore water the area twice a day or as needed to keep the top inches of soil moist.
How Much Water Do Zinnias Need?
Zinnias need an inch of water each week. Zinnias are very resilient and need less water than most flowers.
In any case, it is important to be accurate and consistent with the right amount of water but look out for certain factors before providing water. For example, if they are planted in moist soil, you should water them a little less than if they were planted in dry soil.
If planted in particularly dry soil, increase watering in small increments to keep the soil consistently moist since they need moist soil to grow optimally. This is especially true for young plants.
How much water do zinnias need? Water deeply several times a week to keep the soil moist 6 to 8 inches deep.
How Much Water Do Zinnias Need Per Day?
Zinnias don’t usually need water every day unless you’re watering newly planted seeds. Be sure to moisten the soil to a depth of 15cm (approximately 6 inches) for young zinnias. This allows them to develop a strong root system that will ultimately give the flower a healthy appearance.
How much water do zinnias need? Water the zinnia seedlings daily until they sprout.
If you live in an area where the soil dries out quickly, you may want to split your watering into separate sessions rather than giving the zinnias a full inch of water at once.
If you are watering seeds that have not yet germinated, water them lightly every day to keep the top of the soil moist. Then reduce watering once the seeds have sprouted.
How Do You Water Zinnias?
Water should be given to zinnias regularly to keep the soil moist but not waterlogged. When watering, soak the soil until it is moist and water reaches down to the roots.
When the earth is dry, it’s time to water again. Watering zinnias by hand is not as effective as using a drip hose because the water often doesn’t soak deep enough.
The correct way to water zinnias is by directing the water towards the base of the plant as overhead watering can break flower stems and encourage plant disease.
The leaves are very susceptible to fungal diseases and powdery mildew if they are always drenched but the roots need steady moisture, so watering the base is important.
Do Zinnias Like Wet Or Dry Soil?
Zinnias need moist soil, but it must never be soggy or saturated. Soil that is too wet will cause zinnias to develop root rot or fungal diseases.
Zinnias are far more likely to be harmed by receiving too much water than by getting too little.
Because they are drought tolerant, zinnias thrive in dry soil for quite a while, but eventually, this environment takes its toll. You should keep the soil moistened all the time, but be careful not to drown your zinnias.
Can You Overwater Zinnias?
Overwatering zinnia is a common mistake many people make. This is because zinnias require less water than many other plants, so you’d probably think they aren’t getting adequate moisture.
However, since these are drought-resistant flowers, they will survive longer in dry soil than in soil that is too wet. Zinnias are susceptible to damage from overwatering, so use caution when watering.
There are usually physical indications that zinnias are getting excessive amounts of water. Wilting is one common sign when zinnias are exposed to too much moisture.
Fungal diseases are another classic sign of overhydration. These cause holes in leaves, powdery mildew on flowers and leaves, or dark brown spots on leaves and petals.
Additionally, flowers and leaves fall off very quickly if the soil is too wet.
How Do You Know If Zinnias Need Water?
The best way to determine how often to water your zinnia plant is to check the moisture in the top half-inch of soil. As a rule, zinnias need some water when they are thirsty.
However, touching the soil to determine its moisture level is the only sure way to find out if your zinnias need water. If you check and the top half inch is still damp, there’s no need to provide more water.
Stiffness or shedding of leaves can be signs that your zinnias need to be watered more often.
Do Zinnias Require Lots Of Water?
Zinnias require only a watering round or two per week. During this time, use a water hose to water the zinnias because overhead watering damages zinnias in several ways.
How much water do zinnias need? You should water the zinnias only when the top 1cm of soil feels dry and ensure you water zinnias until the top 6 inches of soil is moist.
Zinnias can suffer from overwatering so measure the water to give accordingly.
Since zinnia plants can survive drought conditions, giving very small water is better than over-watering.
Choose a spot that receives a lot of sun with well-drained soil when planting zinnias as the sun and good soil prevents the soil from becoming soggy. This will ensure the zinnias bloom all summer.
Watering Zinnias After Fertilization
Regular fertilization, about twice a month during the zinnia’s active flowering phase, will help improve plant health and flower production. Always water zinnias immediately after fertilization.
This serves several purposes; First, it transports the nutrients from the fertilizer to the roots of the zinnia, where the plant can actively use them. Then, it helps reduce the risk of nitrogen burn of the zinnia plant’s tissues from the fertilizer.
Additional Watering Tips
When applying water to a bed of zinnias, spread 3 to 4 inches of mulch over the zinnia flowers to reduce the amount of water lost through evaporation. Not only does mulch retain soil moisture, but it also helps block out weeds that would compete with zinnias for watering.
Zinnias: End Of Season Care
Dividing and Transplanting:
Zinnias are annual flowers, so dividing them is not necessary. However, they can be difficult to transplant. If you’re growing them indoors for transplanting, use larger peat moss or plastic pots so you don’t have to repot anymore.
Try not to disturb the roots when moving the plants.
Pests and Diseases:
The biggest pests of zinnias are powdery mildew and Japanese beetles. Powdery mildew is particularly common in humid areas of the country in late summer.
A white film forms on the leaves and eventually the leaves will turn yellow and fall off. To prevent powdery mildew, space plants further apart to improve air circulation, breed disease-resistant cultivars, and take preventive measures:
1. Spray neem oil early in the season. It prevents the spread of powdery mildew.
You can make your organic spray by adding 1 tablespoon of baking soda to 1 tablespoon of neem oil in 1 gallon of water.
2. Aphids can also attack zinnia leaves, causing them to curl and turn yellow. Kill aphids on zinnia leaves with a strong jet of water from a hose.
3. Japanese beetles love to attack zinnias and will often feed on and shred the leaves. To control Japanese beetles, apply and drop beneficial nematodes or milky spore dust in early summer to kill the white larvae in the soil.
To reduce adult beetle populations in summer, you can handpick the adults in the morning while they are lazy and throw them in a bucket of soapy water.
Frequently Asked Questions
How Do You Keep Zinnias Blooming?
Prune them regularly by pinching back old growth and do not overwater them. Let them get enough sunshine too.
Do Zinnias Do Well In Pots?
Yes. Zinnias are not difficult to grow from seed and this is one reason why they make good container plants.
Do Zinnias Do Better In Pots Or The Ground?
Zinnias planted in pots can do just as well as those planted in the ground. Just make sure the pot has drainage holes for excess moisture to run off and use good potting soil. Remember to put them in locations they can receive sun every day, like the patio.
Do Zinnias Come Back Every Year?
It depends on the variety of zinnia. Most are annuals and do not come back every year. The perennial type mostly found growing wild can bloom year after year.
How Much Sunlight Do Zinnias Need?
Zinnias need 6 to 8 hours of sun every day.
How Often To Water Zinnias In Pots?
Zinnias grown in pots need to be watered with an inch of water at least once a week.
How Long Do Zinnias Bloom?
Zinnias can bloom for 2 to 5 months if all conditions are right.
Zinnias don’t need water every day so how much water do zinnias need? Moistening the soil to a depth of 15 cm (6 inches) is enough water for zinnias.
Do this once or twice every week with a drip hose when the top half-inch of soil feels dry to the touch. Try to keep the soil around the zinnias moist but not soggy.
Always water zinnias at the base of the plant, making sure the water doesn’t touch the foliage. Splashing water on leaves can transfer fungal spores from the ground to the leaves and easily break delicate flower stalks.
Zinnias are drought tolerant and can survive in dry soil for a while. Don’t overwater, because zinnias can suffer from rot diseases, especially in a moist, loamy soil.
There are other signs that your zinnias are getting too much water than they need but wilting is almost always the first sign that you have overwatered your zinnias. Therefore, be vigilant by checking the soil to see if your zinnias need water first.
If you give zinnias the specified amount of water, they will respond by producing many colourful blossoms year after year.