Sunflowers are annual plants with big, daisy-like blooms. Its scientific name is derived from the Greek words “helios” (sun) and “anthos” (flower).
When most people think of sunflowers, they think of the tall, bright yellow flowers that dot the prairie landscapes of the country. Many garden varieties, however, are intended to be small and can be planted in a variety of hardiness zones.
The sunflower is a wonderful plant that’s easy to cultivate and a great addition to your veggie or flower garden.
In this care guide, you will find all the information you need to grow healthy sunflowers.
Why You Should Consider Growing It
Sunflowers can withstand high temperatures, are pest-resistant, and attract pollinators and birds with their vibrant blooms that last all summer.
They produce lovely cut flowers and provide sustenance for both humans and birds in the form of seeds and oil.
Sunflowers are heliotropes, so they turn their blooms to face the sun. That means the flowers turn as the sun moves across the sky from east to west. They then turn their flowers back to face the east at night to be ready for the rising sun. The plants only stop turning once their flowers have become heavily seeded.
There are many different types of sunflowers available now, so you are sure to find one or several varieties that suit your needs. You can choose from branching varieties or those with a single stem. Some have abundant pollen for pollinators, and others have very little, making them ideal for bouquets. You can have small sunflowers or those that tower over the rest of your garden. And finally, you can choose from varieties that bear little or lots of edible seeds.
Best Time to Plant
After the danger of frost has passed and the soil has warmed up to at least 50 degrees Fahrenheit, you can safely plant sunflower seeds directly into your garden soil or outdoor containers.
In the northern half of the United States, this will be between April and the middle of June. In the southern states, you are likely to sow seeds in the middle of March or the beginning of April.
If you want to start the sunflowers indoors, plant the seeds5 to 7 weeks before the final frost is possible. Before transplanting the seedlings outside, bring them outdoors for a little while every week to acclimate them. When moving the plants to their final spot in your garden, make sure not to damage the roots.
If you opt to start your sunflowers indoors, they will bloom earlier as a reward.
General Care
Sunlight and well-drained soil are the only prerequisites for growing thriving sunflowers, no matter which variety you select. If at all possible, choose a spot that is protected from severe wind gusts that may topple these tall plants. Sunflowers may protect each other from wind and rain if they are planted in groups.
Read on for the basic care needs of sunflowers.
Water Needs
Sunflowers can survive in dry environments, but plants often cease flowering during droughts. So regular watering will encourage flowering.
Between waterings, let the top 1 to 2 inches of soil dry out. Your sunflowers likely need extra water if they are drooping and the soil feels very dry.
Amount of Sun
Plant your sunflowers in full sun, which is defined as receiving at least 6 hours of direct sunshine on most days, for the greatest blooming and strongest stalks. Their flower heads follow the sun because they are heliotropic; exposure to plenty of sunlight will prevent them from bending in the direction of the light source.
Fertilization
A fertilizer heavy in phosphate and potassium helps sunflowers to set blooms on those long stalks.
You may not need to add fertilizer if your soil is rich and loamy. However, if your soil is poor, start applying slow-release fertilizer in the spring, following the product’s directions. Avoid overfeeding your plants to prevent stiff stems from developing.
Other Maintenance
Aside from the basic care described above, consider the following when caring for your sunflower:
Pruning
Perennial sunflowers should be pruned twice a year. At the start of the summer, decrease their size by half, and in late June or early July, reduce it by another third. If you are raising one of the large species, you may want to think about trimming it around June to about two-thirds of its original size.
Mulching
Mulching the area surrounding your sunflowers can assist in both retaining moisture in the soil and preventing the growth of weeds.
Staking
Sunflowers, particularly the tall types, sometimes need to be staked to keep them growing straight. When in flower, the plants may become quite top-heavy. Planting sunflowers along a fence is the easiest way to provide support.
Bamboo stakes are also sturdy enough to hold them upright. Stakes should be inserted carefully to avoid damaging the plant’s roots.
Best Time to Plant
Picking the right time to sow sunflower seeds involves some patience. Sunflowers should be planted in the late spring when the earth has warmed up. Most sunflower seeds will germinate when the soil is between 70 and 85 degrees F.
Sunflowers grow best when planted just before the soil reaches this temperature. Be on the lookout for a ground temperature of 60 to 70 degrees. This will be three weeks after the last frost in most places.
Sunflowers may be planted inside to jumpstart their growth. After the final spring frost, slip the seeds into peat pots. Once the soil reaches the proper temperature, you can easily transplant the seedlings outside.
