What Kind of Soil is Best for Growing BIG Sunflowers?

[ArtB]

I want to grow some large sunflowers this year just for the heck of it. Got some Mammoth seeds fromr Burpee,what kinda soil & how can I get them to grow huge?

[ElizabethB]

Really easy to grow. Because they get so huge you need some kind of support for them. I have grown them next to the utility pole in the back corner of the yard. Honestly I did nothing special. Scraped the grass off. Turned the soil a little and planted the seeds. Watered periodically. BTW - full sun. As they grew I tied them loosely to the pole using strips of old tee shirts.

The neighbor's children went nuts over the sunflowers. The following year their Mother planted sunflowers on her side of the fence using the same pole for support.

Lots of fun especially if there are young ones around.

Good luck

BTW -- as the seeds develop you will have very happy birds pecking away at the face to get those oil rich seeds.

Since I grew them "just for fun" I did not attempt to harvest the seeds - I just left them for the birds.

[applestar]

There's a picture in a thread when I grew them. They didn't get huge flowerheads but were very tall. I did nothing special for them specifically, though it was part of a new garden bed project. I imagine they do get bigger if fertilized.

I've noticed sunflowers grow well in lawn-turned into- new planting bed.

[Susan W]

I usually start sunflowers in peat pellets or cups inside as sometimes the birds get greedy and eat the new planted seeds from the ground.

[imafan26]

I have grown mammoths before. Mine got about 8 ft tall, so I did use a stake (rebar is strong), but I have grown them without stakes too. They do not require anything special as long as you have good soil. They will need to be spaced a couple of feet apart, the roots spread out sideways and it is best not to plant them in hard pan. They do like full sun and it is fun to watch the flower follow the sun throughout the day. I direct seeded them.

If you want sunflower seeds you need to plant more than one, lately I have been getting a lot of empty shells and I read that they don't self pollinate all that well and they do need multiple bee visits. Some sunflowers are now being bred to be seedless.
If you do want to collect the seeds you may have to cover the heads or the birds will get the seeds.

[Cola82]

I usually start sunflowers in peat pellets or cups inside as sometimes the birds get greedy and eat the new planted seeds from the ground.

Maybe that's what happened to mine. I planted eight and only four have come up.

[applestar]

This year's pre-germinating experiment confirms sunflowers respond really well to this technique.
You don't need a fancy sprouter if you don't have one. So far, Tostito,s salsa jars are working well for me. Soak 4-6 hrs, then rinse and drain completely 3-4 times a day (more often when it's hot) and keep the jar on its side NO LID OR COVER. I'll post photos in the experiment thread later.

[skiingjeff]

Something else to keep in mind about the mammoth sunflowers, they always face East...

We didn't realize this the first year we planted them and all we saw were the back of the flowers....lol

Now we plant the location so we can enjoy the flowers and the birds that they attract.

We collected seeds last year and have started them from those seeds this year. It will be interesting to see if they grow as big and tall as the prior year's.

Good luck with them!

[applestar]

It's true!

I once planted the gray striped sunflowers in a row along the fence bordering my neighbor -- their house has a pretty narrow side yard -- and when they opened, all the sunflower faces ended up looking into their family room window. ...with little variations that make them look like they are having a conversation with each other....

I have no idea how that looked from their side, but I imagine it must have been hilarious.

Consider well before planting.

[imafan26]

You are right the head always faces east but will follow the sun throughout the day. Mine would face straight up at noon but will drop back towards the east by the end of the day.

[applestar]

Big seeds like sunflowers pre-germinate best if soaked first. About 4-6 hours in tepid (not hot or warm, but not cold) water, then rinse with fresh water and drain.

After that, the "Baggie method" is likely to work, but I have been using a seed sprouter and rinse/drain them 3-4 times a day -- same method as for making soybean and mungbean sprouts except I don't let the roots grow long and sow the seeds as soon as they emerge. A wide mouth jar can be used instead -- rinse, drain and lay the open jar with wet seeds on its side.

Link to my thread about pre-germinating https://www.helpfulgardener.com/forum/vi ... 48&t=57487