Last Updated on June 7, 2022 by Marco C.
Sunflowers are an incredible plant to grow! I always plant a small patch of them every year, as they are great forage for my bees, good feed for my chickens and the wild birds enjoy pecking away at them too. There are a few things that can go wrong with sunflowers when you grow them. There are easy ways to fix these problems. Sunflower petals turning white is one such problem.
A Quick Note
I write from a position of experience, having done a lot of stuff in my life. Hence if you find my take on things varies from the other websites you read, there is a reason. I have done this stuff and I actually care about what I write. I write from a position of experience and understanding. Rant over.
Understanding Sunflowers
These plants are in the daisy family and fall in the genus Helianthus. They are characterized by big beautiful flowers that look a bit like the Sun (Helios). There are a lot of species in the genus Helianthus, with around 70 or so being recorded. We typically refer to Helianthus annuus as The Sunflower. This is the Sunflower that is grown commercially giving us joys such as sunflower seed, sunflower oil, sunflower oil cake, and sunflower honey.
I once did my Ph.D. on making mead (honey wine). As a final list of “future projects,” I wrote that it would be really fun one day to keep bees on a sunflower field and make sunflower honey. The bees would pollinate the crop and the honey would be a by-product. Then I wanted to ferment the honey into mead (honey wine) and three months later collect the sunflower seed and use that to make biodiesel from sunflower oil to take our product to market. I actually managed to do this!!
There is another plant in the Sunflower family that is well worth knowing about as a gardener – this is the Jerusalem artichoke, Helianthus tuberosus. These are great for cutting flowers, and the nice thing is you get a crop of potato-like things that you can cook. Be warned -these induce exceptional flatulence so do not eat them if you are going on a road trip, or need to sit in a meeting the next day. Just trust me on this. Some people call them Fartichokes.
How To Grow Sunflowers
Choosing Seeds
These are really easy to grow. They are tough!! If you get old heirloom varieties you can just keep your seed and plant each year. Keep the seed from the biggest heads for planting the next year. I have this weird dark seed type that I bought from a granny on the side of the road in Zimbabwe once. This strain is the gift that just keeps giving – I have been growing it for 15 years and it gets better and better each year.
Preparing Soil
I typically like to mix hot soil for sunflowers. I mix about a 5-gallon bucket of relatively fresh horse manure per square yard. I add one cup of agricultural lime per heap of manure. Sunflowers like slightly alkaline soil. I have a rotavator that used to once look a bit like this. Everything that was not essential has broken and fallen off and it still works. These things are great for ripping up a useless lawn and turning it into a food patch! I run the rotavator over the soil and then plant my sunflowers. I space my specific cultivar at 2 feet apart per plant. I also plant a bean on each sunflower.
Germination
The sunflowers need about two inches of rain, or equivalent to irrigation to trigger them to germinate. After they germinate, every weed on earth will try and smother them. This is where I use mulches – when a sunflower gets to be about four inches tall you can much heavily with leaves and lawn clippings – I cover the ground in a layer at least four inches thick, and leave just the tops of the sunflowers sticking out of the mulch. With any luck, you will not have to worry about weeds.
Beans and Pumpkins
I always plant beans with my pumpkins – they grow together. I have my own strain of purple pole bean similar to the one that I use. The bean’s roots intertwine with the sunflower. The bean fixes nitrogen and the sunflower mooches some of this. The sunflower provides the bean with something to grow on. The bean lifecycle is longer than the sunflower so it means you get the benefit of a crop of sunflowers and a crop of beans, without destroying your soil.
I normally plant a gem squash or my new favorite – jack b little under the whole lot. These will rapidly cover the underlayer below the sunflowers and help to manage soil moisture and heat. This is really important to stop your sunflower petals from turning white.
How To Stop Sunflower Petals Turning White
My general experience is that sunflower petals turning white happens when they get burnt in the sun due to not managing thermal reflection in the garden. Sunflowers track the Sun as it moves across the sky. On very hot days, reflected heat from the ground, and heat from the sun can cause the petals to just give up and bleach. This is why I make sure I have an undercover of plants and mulch to keep the microclimate below the sunflowers cool and productive. Squash plants also help to move water out of your soil quickly stopping the soil from getting waterlogged. Sunflowers do not like to have their roots get too wet. If you use the above method, you will hardly ever have your sunflower petals turning white.
Learn more about: White Sunflowers Seeds For The Garden
Controlling Mold and Diseases In Sunflowers
When I first started growing sunflowers I planted them straight in barren soil. The plants thrived but were disease-prone. They attracted all sorts of irritating things that damaged the leaves and caused mold, smut, and similar problems. I had a lot of problems with sunflower petals turning white.
Survival Of The Fittest, Not The Sh$%^Test
In my garden, I try to maintain a balance of predators that eat pests. This is what mulch is for – it provides a home for insects, predatory mites, little wasps, and the plethora of things that are not there on commercial farms due to pesticide use. You will find that if you create the right conditions, these beneficial organisms build up year after year. Do not keep seeds from weak plants – let them die. Keep seeds from your best plants. This way you produce locally adapted seeds. You may get a little mold in your first year or two – and selecting seeds from the plants that do not die, means you now have plants that are mold resistant in your area.
Do not go and spray your plants with fungicides and such things. This just prolongs or stops you from ever getting to the point of having any locally adapted seeds. You need to have the fittest survive – if you use fungicides you enable the survival of the s*&^tist, which is not in your best interest. Likewise, do not keep seeds from plants that suffered from the sunflower petals turning white.
Duck Water
If you have duck water for irrigation, you will find your plants are less susceptible to diseases. Duck water is what people in the east use in order to be productive. You keep ducks in your reservoir. Ducks poop – a lot. The water goes green. It is teeming with microbes – when you spray this on your plants, the beneficial microbes create a barrier to pathogens. The ducks also control slugs and snails in your garden. So duck water is good – as are ducks. Ducks are also tasty as are their eggs. This is a form of snail control that is nutritious and sustainable. I keep Muscovy ducks because they don’t make a noise and have a demonic urge to eat snails, slugs, locusts, field mice, rats, small snakes, and so on.
My source of duck water. I keep a few Muscovy ducks in my garden. In spring these turn into a lot of Muscovy ducks. These ducks go and eat slugs and snails and other things in the garden. Then they come to have a swim and poop in the dam. The dam gets very green. This is full of beneficial microbes that are great for irrigating the garden. The floating bottle is my pump intake – I try to take the most disgusting water into the system because I want all the microbes to be sprayed on the leaves of my plants. This reservoir fills with runoff water from the street outside my house.
Timing Of Your Sunflower Planting
You need to time sunflower planting so that they flower at the point in the year when it is humid and hot. This is also a time when they are resistant to the sunflower petals turning white as the humidity protects them. This ensures the biggest sunflower heads and the best pollination, and honey production. If you look at the data for your area, find the warmest month, and count back 160 days from the middle of that month. That is when you plant your sunflowers. In some areas, you may have to count 130 days if you have a long photoperiod and short summer. For me, 160 days works.
Sunflowers are a great source of nectar for native pollinators. Depending on where you are there are many interesting wild bees that will thrive on your sunflowers and pose no threat to you. Bees such as carpenter bees are also great for your beans. You can buy a little nest for them here.
What Do You Get From Your Sunflower Patch At The End Of The Season?
You will get a sunflower head from each sunflower. These can contain up to two cups of seeds! I just keep the heads in a bag after they are dry and throw a sunflower head or two into the chicken coop. They peck the seeds out as they need them. You will also get about two to three cups of dry beans per sunflower plant. This is a very valuable protein. The jack b little pumpkin is so prolific you will get sick of eating them. I boil them and feed them to my chickens. I prefer eggs to jack b little pumpkins after a while. What this means is that per square yard of your sunflower/bean/pumpkin patch, you are looking to harvest 5-10 squash, two, maybe three sunflower heads, and a few cups of beans! You also produce a huge amount of biomass which you return to the soil and enrich the soil. Each year your crop gets better.
I normally plant potatoes on the soil after this cycle – I do three crops a year on my soils, so the potatoes are the fall to early winter crop, and then winter is cabbage/broccoli/cauliflower/kohlrabi.
I hope this has allowed you to hear how to genuinely make your garden a better place! Sunflower petals turning white are a symptom of not having the right heat management strategy in place. This is what companion planting is for. Sunflowers are an essential tool for any self-sufficient gardener to grow and use to make the garden more productive. This produces chicken food, shade, biomass, and bean support and enriches your pollinator population. Win-win win. If you found this inspiring please share.
Read more about: Why Are My Sunflower Leaves Turning Brown
FAQs
How do you treat white mold on sunflowers?
I have my own theory about this. Plants that develop white mold are just not adapted to the local conditions. If a plant gets it, let it die. Some of the other sunflowers will not, and they have genes that make them suited to your area. Keep those seeds and plant them the next year. After a few years of this, your locally adapted seeds tend to not get mold.
What do Overwatered sunflowers look like?
They look like dry sunflowers - the leaves hang and are wilted. If the sunflower looks dry, but the soil is wet, then it is probably overwatered.
Can plants recover from sunscald?
Sometimes. This depends how badly the plant has been scalded. If the growth shoots are dead, and the stem is burnt, the plant will die. If the leaves have a few burnt patches, the plant should recover. Maybe if you keep having this problem try putting a but of shade cloth up.
How do you revive a dying sunflower?
This will depend why it is dying. If you planted it too late and the days are getting short, let it die - try to plant them earlier next season. If you overwatered it, it will look dry, but the ground will feel wet. Do not water it, and you can use a fork to poke a few holes in the soil around the stem to aid aeration and drying.
Dr. Garth A. Cambray is a Canadian/South African entrepreneur and beekeeper with 28 years of experience in apiculture and specializes in adding value to honey. His Ph.D. research developed a new advanced continuous fermentation method for making mead that has resulted in a number of companies globally being able to access markets for mead. His company, Makana Meadery, exports honey mead to the USA where it is available to discerning connoisseurs. He has also developed technologies to commercially manufacture organic honey vinegar in Zambia for export globally. He holds a few patents globally in the ethanol industry and believes in technology and knowledge transfer for human development and environmental sustainability. One of his proudest achievements is the fact that the wind farm he started at one of his old apiary sites has essentially made his hometown carbon neutral.
