Sunflowers have always been big, bright, and cheerful, but it used to be that they were a little… uniform. A little… one-dimensional. Basically, they were yellow, and while yellow is lively and cheery and all kinds of wonderful, there’s only so much of it you can take before you get sick of it. But times change. Sure, you can still get yellow sunflowers if you want to stick with the traditional, but now there are rusty red, chocolate brown, green, white, and even purple ones to enjoy. If your garden’s calling out for some variety, here’s exactly what you need to know about how to grow your own purple sunflower.
Step 1: Choose a Spot
As their name suggests (and as Hunker explicitly outlines), sunflowers need full sun to thrive. Forget about cheering up a dark spot in your garden with some sunflower magic: unless they receive a good 6 to 8 hours of direct sunlight every day, they’ll be less magical and more miserable.
Step 2: Prepare the Soil
Sun is important, but the right choice of soil is equally so. If you’re growing your purple sunflower from seed (as is recommended), fertile, well-drained soil is your best bet. If you intend to grow the plant in a container, start by taking the advice of MNL Growkits and fill your chosen pot with a decent amount of soil, leaving around a quarter of an inch of space between the surface of the soil and the rim of the pot to allow for growth. As sunflowers don’t respond well to being re-planted, use a biodegradable pot you can simply pop in the ground when you’re ready to move them outdoors.
Gently press the soil to remove any air pockets, then give it a good soaking to provide the right conditions for germination. Add 1 to 2 seeds per pot and cover them with around 3-6mm of soil. Lightly water. Cover the pot with a clear plastic kitchen wrap to avoid heat and moisture loss. Before securing the wrap, lightly spray the side that will come into contact with the soil with water. During the germination period, remove the wrap twice daily to water the pot. If you intend to direct sow outside, plant the seeds around 2 inches deep in the soil and about 6 inches apart. The best time to sow is in the spring after the last frost. If scavenging wildlife is a problem, be sure to cover the planted area with netting.
Step 3: Prepare for Vegetation
If you’re growing your plant in an indoor container, remove their plastic wrapping once you notice the first green tendrils starting to emerge, Usually, this will be around 6-12 days after you sow the seeds. Now that the germination stage is over, you can move into the ‘vegetation’ period. During this stage, keep the soil moist by watering it lightly in the morning and evening. To ensure healthy growth, pull out the weakest seedlings – these can either be discarded or transplanted into other pots. Keep the pot well watered until the end of May. As gardenersworld.com recommends, once the last frost has passed, prepare for planting out by removing any weeds from the soil and adding plenty of organic matter.
The plants should be planted at the same depth they were in the pot. Add plenty of water to encourage root formation and if necessary, stake the plant with a bamboo cane. If you’re growing the plant outside, now’s the time to increase your watering. Make sure the root zone, which spreads around 3-4 inches away from the plant, is saturated with enough water to encourage deep rooting. Although established sunflowers are remarkably drought-resistant, saplings aren’t. Until they are fully established, aim to water them with several gallons of water at least once per week – if the conditions are exceptionally dry, this may need to be increased to twice a week. As insects, snails, and slugs can pose a risk to your little saplings, it’s worth considering adding bait around the base of the plant to protect them during this delicate stage in their development.
Step 4: Disease Management
Pests and insects both pose a major risk to developing plants. Sunflowers are generally less attractive to insects than other plants, but that doesn’t mean you can afford to be lax. Snugs and snails are both problematic, as are the small gray moths that occasionally lay their eggs in the blossoms. To stop the carnage, pick away any worms you see on the plant. If fungal diseases like mildew and rust become a problem, over-the-counter fungicides should soon stop the damage.
Step 5: Feed… But Not too Much
Sunflowers don’t need a lot of food (too much fertilizer can result in weak growth and few flowers) but they shouldn’t go hungry. A slow-release fertilizer applied once a year during mid-summer is best for outdoor varieties. If you’re germinating them indoors, fertilize the soil around 14 -21 days after the first sprouts emerge, and every 15 days thereafter. Remember to water after fertilizer has been applied to encourage faster absorption.
Step 6: Prepare for Harvesting
By now, your little green saplings should have grown into strong, healthy plants. If you want to turn them into a floral display, cut them during the early morning to avoid the risk of them wilting. If you want to harvest the seeds, wait until the seeds turn brown and dry and the back of the flower head turns from green to yellow (usually, this will be around 30 – 45 days after planting) before removing the flower from the stem. Once removed, hang the flower upside down in a dry place until the seeds are completely dry. Once they are, remove them with either a fork or your fingers. If you prefer, you can cut the flower head before it ripens fully and hang it upside down until the seeds turn dry and brown. Once harvested, the seeds should be dried for a few days to remove any last traces of moisture. They can then either be eaten or used to grow a new batch of sunflowers the following year. If you intend to sow the seeds, be sure to keep them in a paper envelope in a dry spot to prevent mold or mildew from setting in.