Why All the Buzz About Pollenless Sunflowers?

20180226A Zohar www.johnnyseeds.com.jpg

Pollenless sunflowers, like ‘Zohar’ above, look much like any other sunflower, but don’t produce pollen. On a normal sunflower, there would be a ring of yellow pollen-tipped anthers around the disk, absent here. Source: http://www.lowes.com

If you’ve checked the sunflower (Helianthus annuus) page of any seed catalog lately, you’ll see that pollenless sunflowers are all the rage. They’re very popular with florists, for example, as they don’t produce annoying yellow pollen that falls unto furniture and clothes. But what the catalogs fail to mention is that they aren’t very bird and pollinator friendly either and if you’re trying to attract wildlife to your garden, they’re exactly what you don’t want!

History of the Pollenless Sunflower

Pollenless sunflowers originated as a mutation, a genetic error. They are male-sterile: the hundreds of individual florets that compose the composed inflorescence of pollenless sunflowers (Helianthus annuus) produce no pollen. This would be a disaster in the wild, but for hybridizers, it’s a boon.

 20180226B lambley.com.au.jpg

Creating sunflower hybrids used to require a lot of time-consuming manipulation. Source: lambley.com.au

Previously, hybridizers had to cut off all the tiny pollen-bearing anthers from the flower they wanted to use to create a new variety so as to avoid accidental self-pollination, then carefully carry pollen from the male parent flower to the emasculated female parent flower by hand, a long and tedious process. With pollenless sunflowers, they can just release a few bumblebees into a greenhouse containing a normal bisexual (hermaphroditic) sunflower and a pollenless one. The bees will then carry fertile pollen from the bisexual flower to the male-sterile one and any seeds formed on the pollenless flowers are therefore hybrids. Bingo!

At first, pollenless sunflowers were strictly used for hybridization purposes and never made it to people’s gardens, then someone realized that there would be a market for pollenless sunflowers in the florist industry. Indeed, flower arrangers love them: no extraneous pollen to brush away and also pollenless sunflowers have a longer vase life. What more could a florist ask?

Ideal for Allergy Sufferers?

20180226C www.theodysseyonline.com.jpg

People rarely develop allergies to sunflowers as their pollen is not wind-borne. Source: www.theodysseyonline.com

An odd thing that is brought up by promoters of pollenless sunflowers is that they are nonallergenic and therefore ideal for hay fever sufferers. But then, regular sunflowers rarely cause problems for hayfever sufferers either. So why the fuss?

You see, sunflower pollen is not wind-borne and will not be carried in the air like tree, grass and ragweed pollen is. You’d practically have to stand under a blooming, pollen-rich sunflower and shake it while breathing heavily to absorb any pollen into your nostrils. This occurs so rarely that few hayfever suffers have ever come into contact with sunflower pollen … and you need a previous exposure to any new type of flower pollen before you’ll react to it.

So, unless you’re a commercial sunflower grower given to working in fields of sunflowers or a florist who manipulates many sunflowers, the pollen allergy conundrum is of little importance. Certainly, the casual sunflower grower has nothing to fear from sunflower pollen.

The Birds and the Bees

Today, pollenless sunflowers are widely available to home gardeners who, I suspect, grow them without realizing their full effects on wildlife.

20180226D www.kidsdiscover.com.jpg

Bees need both pollen and nectar and will therefore prefer bisexual sunflowers. Source: www.kidsdiscover.com

Bees of all sorts visit sunflowers seeking nectar and pollen: they need both to feed their young. Pollen, for example, is their principal source of protein: they can’t survive without it. They will visit pollenless sunflowers, as they still produce nectar, but will then have to put in extra hours collecting pollen somewhere else. In these times when bees are struggling to survive, does it really make sense planting flowers that will make their life even more stressful? Bees eventually learn to avoid pollenless sunflowers, preferring pollen-rich flowers.

Other pollinating insects may or may not frequent pollenless sunflowers. Most pollinating beetles, for example, will avoid pollenless sunflowers: they’re pollen eaters. Butterflies and hoverflies, however, feed mostly on nectar and are unfazed by pollenless sunflowers.

If you’re like me, the main reason you grow sunflowers is to feed the birds. I leave mine standing all winter and get to enjoy visits by birds of all sorts. And if you sow pollenless sunflowers near bisexual sunflowers, they probably will be pollinated to some degree and will therefore produce seed. Great! But if you planted only pollenless sunflowers in your garden and none of your neighbors grow bisexual sunflowers, you can forget about feeding birds: no seed will mature. Bummer!

Harvesting Seed?

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If you intend to harvest seeds, you’ll want to grow “ordinary” (bisexual) sunflowers. Source: myculturedpalate.com

If you like to harvest seed of favorite sunflowers for next year’s garden, you won’t appreciate pollenless sunflowers. They are never true to type whereas non-hybrid sunflowers will be. There is therefore no use harvesting the seed of pollenless sunflowers.

As for harvesting seed for eating, that’s easy. The large-seeded types grown for that purpose are always bisexual. It would make no sense to develop pollenless large-seeded sunflowers: they would likely never produce a normal crop!

You Choose

So, here’s the situation in a nutshell. For most gardeners in most situations, pollenless sunflowers are not pollinator- and bird-friendly, nor are they good for harvesting. So, when you see the mention “pollenless” in a seed catalog, take that to mean a variety that’s best avoided. However, if you’re specifically growing sunflowers for use as cut flowers, you’ll probably be thrilled with pollenless sunflowers.

Clear enough?


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