Sunflower seedlings should be watered daily so the soil is moist but not soaked. As the sunflowers become established, they can be watered once a week.
As the seeds germinate, you will need to water them every day. This is because seedlings need more water compared to mature sunflower plants. However, remember not to overwater them. Overwatering at any stage will kill the plants faster than you can imagine.
Although sunflowers require a lot of water to germinate, they only require an inch of water per week during the growing season. Use a watering nozzle to easily water once a week until the top 6 inches of soil is moist.
Most sunflowers take about 2-3 months to grow from a seed to a mature plant. Shorter types with a single head may start blooming less than two months after the seed is planted, while giant sunflowers may not start to bloom until 3-4 months after planting.
Sunflower seeds need stretched seed skin (scarification), then soaked warm water (40-50 C) for 25 minutes. Then the process of germination, next sowing in place of exposed to direct sunlight, and only then planted as well as cared for.
Place one seed in the divot and cover it with soil. If you have extra seeds, you can put 2-3 in one hole and then trim off the two weaker seedlings. Water the soil gently to help settle it. Sunflower seeds of most varieties should be planted about 18-24 inches apart, as they will grow to be quite large.
Sunflowers (Helianthus annuus) are annuals, meaning they must be planted early to late spring, depending on the temperature in your growing zone. You'll know when to plant sunflowers once the soil temperature reaches at least 60 degrees Fahrenheit1 and all danger of frost has passed.
8. One Sunflower Produces Around 1,000 Seeds. Each sunflower head can contain as many as 1,000 to 2,000 seeds. Each seed can be quite different when it comes to appearance, but the most common kind used for snacking has a black and white striped pattern on the hull.
Ensure that the soil has good drainage. Avoid letting the water sit for too long near the stem because the sunflower's root and stem may rot. It also causes the plant to be unstable. Sunflowers need to be watered regularly, about once every 3-5 days, depending on the weather and soil conditions.
Sunflowers grow best in full, bright sun, and in evenly moist, well-drained soil. The amount of space they need depends on which varieties you are growing. Branching types with multiple blooms on one stem need more space horizontally than large single-flowered types.
For vegetables in the summer, we recommend applying about 1 inch of water over the surface area of the garden bed per week. That is equivalent to 0.623 gallons per sq ft. Using that rate, a 32 sq ft bed requires 20 gallons of water per week.
Signs of Overwatering Flowers
If you notice that your flowers are wilting, then you should check for these signs of overwatering. The flowers will be drooping and wilted. Leaves on the flowers may look yellowish. The Flower may have a brownish color.
Sunflowers will let you know when they are dry and need water. Inspecting the soil will also help you determine if the plant needs water. Leaves wilting, drooping, and turning yellow and brown are signs of an underwatered sunflower.
Some sunflowers are annual and survive only one season, and others are perennials that will return every year. All perennial and annual sunflowers produce brilliant flowers that are a highlight of any late-summer garden.
The allelopathic characteristics of sunflowers are toxic to some plants, potatoes being one of them. This process inhibits germination and can stunt the growth of potatoes. They also compete for nutrients in the soil. Potatoes should be planted well away from sunflowers to avoid them affecting one another.
The answer is no. It's possible to sow sunflower seeds in summer, up until August and possibly even later, depending on when your fall frost begins.
The narrow end of the seed is where roots will emerge, so putting this end down saves the plant from having to right itself in the ground. Place the sunflowers 1 to 2 inches deep, point-down, every 6 inches or so, and then cover them up.
If you plant closer, you might get taller stalks but smaller heads. If you plant farther apart, the seed head may be larger, but possibly too heavy for the stalk to bear. If you have limited space, Tom recommends sowing in a small clump that will eventually be thinned to one plant.
Number of holes x Germination rate = Number of Plants
Let's start with 72 holes and one seed each that has a 70% germination rate. You would multiply 72 by 80%, and get roughly 57 sprouts. In this case, you can plant 2 to 3 seeds per hole and you'll probably experience maximum success.
You won't have to water after they are planted, preventing seed movement. Create a mini greenhouse by covering the seed tray with a plastic tray or plastic wrap. This will keep the moisture and warmth inside, and you shouldn't have to water again till after the seeds have germinated.
Your seeds will require dark to germinate, so they must be planted at the appropriate depth. For most sunflower varieties, that's somewhere between a half and three-quarters of an inch deep, but you should look up the depth specific to your variety just to be sure.
Optimal temperatures for growing sunflowers are between 70 and 78 F. Still, they tolerate high heat as long as their moisture needs are met.