Sunflowers are annuals that produce large or small yellow flowers in the summer. They are highly prized for their beauty and ease of cultivation. Planting sunflower seeds in the spring can be a fun activity for adults and children. It is enough to have a minimum of time and preparation.
Steps
Part 1 of 3: Germinating the Seeds
Step 1. Check the outside temperatures
While growing sunflowers can start indoors, they grow best if they are moved outdoors within a week. The ideal temperature is between 18 and 33 ° C, but they can also withstand lower temperatures once the last frost has passed.
Sunflowers usually need 80-120 days to develop and produce new seeds, depending on the variety. If the growing season is shorter in your area, plant them two weeks before the last frost; most of the seeds will probably survive
Step 2. Choose a variety of seeds
There are many varieties and hybrids of sunflowers, but most gardeners usually only check that they meet a couple of characteristics, typically described on seed packaging or listed online. Be sure to check the maximum height of the sunflower, since it can range from less than 30cm for the "dwarf" type, to at least 4.5m for the giant ones. Also, consider whether you prefer a sunflower that produces a single stem with flowers, or one that branches into multiple stems with several smaller flowers.
You can't grow sunflowers by taking roasted seeds, but you can grow them from bird seed, as long as the outer shell is present
Step 3. Wrap the seeds in a damp paper towel
Wet it lightly to moisten it without soaking it too much; it must not drip. Place the seeds on one half of the towel, then fold and cover them.
- If you have a large amount of sunflower seeds and won't mind too much if some won't germinate, you can go straight to planting. Seeds that are planted directly into the ground typically take 11 days to sprout.
- If the growing season is long in your area, try germinating the seeds at different times 1 to 2 weeks apart so the garden will stay in bloom for a longer period of time.
Step 4. Keep the paper towel in a plastic bag
Check it once or twice a day and keep checking once the seeds sprout. Typically, you will notice sprouts appearing from most seeds within 48 hours. When you see them sprouting, you can plant them.
Keep the paper towel above 10ºC for best results
Step 5. Slightly open the edge of the seed shells (if necessary)
If you see that the seeds do not sprout within two or three days, try using a nail clipper to remove the edge of the shell. Be careful not to damage the seed inside. Add a couple of drops of water if you see the paper towel dry out.
Part 2 of 3: Planting the Seeds
Step 1. Choose a sunny location
Sunflowers grow best with 6-8 hours of sunshine per day when possible. Find a spot where they can receive direct sunlight for most of the day.
Unless your garden is exposed to a lot of strong wind, try to keep them away from trees, walls, and other objects that can block the sunlight
Step 2. Check the soil to see if it has good drainage
Sunflowers have long tap roots and may rot if the soil is soaked with water. Dig a hole 60 cm deep to check if the soil is hard and well compacted. If you can get it, try mixing compost into the soil to improve drainage.
Step 3. Evaluate the quality of the soil
Sunflowers are not too fussy and can grow in an average soil type without the need for additional treatments. If the soil is poor and you want to enrich it to encourage growth, mix in some clayey soil. Although rarely, it may be necessary to adjust the pH of the soil, but if you have a kit, you can adjust it between 6, 0 and 7, 2.
Particularly rich soil is recommended for giant varieties, as it requires more nutrients
Step 4. Plant the seeds 2.5cm deep and 15cm apart
Plant them in holes or furrows 2.5cm deep or 5cm deep if the soil is loose and sandy. Keep them at least 6 inches apart from each other to give each one enough space to grow. If you only have a few seeds and don't want to prune weaker plants later, plant them 30cm apart or even up to 45cm apart for giant varieties. After sowing them, cover them with soil.
If you are growing a field of sunflowers to get a large crop of seeds, space each furrow 75 cm or any other distance that is convenient for your machinery
Part 3 of 3: Caring for Plants
Step 1. Keep the soil around young plants moist
Make sure it's moist but not soggy until the sprouts start to sprout. When the shoots are still small and fragile, water them from a distance of 7.5-10 cm, to encourage root growth without uprooting the seedlings.
Step 2. Protect the seedlings from pests
Birds, squirrels, and snails love sunflower seeds and can weed out seedlings even before sprouts appear. Cover the earth with a net to make predator attacks more difficult without blocking the sprouts at the same time. Place bait or snail repellent in a circle to form a barrier around the seedlings.
If your area is inhabited by deer, surround the plants with wire mesh when the leaves begin to grow or protect the garden with a fence that is at least 1.8m high
Step 3. When the plants are more mature, water less frequently
Once the plants have formed stems and the root system has stabilized, water only once a week. On that occasion, wet them abundantly and increase the amount of water in the dry period. Sunflowers require more water than many other annual flowers.
Step 4. Prune the plants (optional)
When the flowers reach about 7.5 cm in height, remove the smaller and weaker ones until the rest are spaced at least 30 cm apart. This way sunflowers will grow larger and healthier by having more space and nutrients available, resulting in tall stems and larger flowers.
Skip this step if you want small flowers to bunch with or if you've already planted them at this distance
Step 5. Fertilize moderately or not at all
If you are growing sunflowers just for fun, fertilizing is not recommended, as they grow well even without them and can suffer if they are given too many nutrients. If you are growing very tall sunflowers, or growing them as a plantation, dilute the fertilizer in water and pour it into a "ditch" around the plant, well away from the base. The most suitable fertilizers are those that are balanced or rich in nitrogen.
Another possibility is to apply the slow-release fertilizer buried in the soil at one time
Step 6. Place poles as needed
Sunflowers that grow over 90cm, as well as varieties that produce multiple stems, may need to be supported with poles. Tie the stem not too tightly to the post with a cloth or other soft material.
Step 7. Collect seeds (optional)
Sunflower flowers often last 30-45 days. Towards the end of this period, the back of the flower's green head begins to turn brown. If you wish to harvest the seeds for roasting or planting them next year, cover the flowers with paper bags to protect them from birds and cut them when they are completely dry.
If left untouched, the flowers spontaneously drop seeds for the next year's harvest. If you collect them yourself, however, you protect them from parasites
Advice
Sunflowers are annuals and die shortly after the flower fades
Warnings
- Sunflowers produce chemicals that can inhibit the growth of potatoes and green beans grown nearby; in addition, if allowed to accumulate, they can potentially kill grass. However, these chemicals are harmless in other contexts.
- Do not plant these flowers against low walls, as the stems may grow between the bricks and damage them.
