I poured a drive on a spec house about a year ago. Last year the home went through the typical pollen drop season from a Red Oak tree, in the vicinity of the drive, with no problems. The oak is huge but the pollen typically drops straight down to the grass below it - never reaching the drive. Anyway, we recently had a severe hailstorm in GA. and it drove all the newly ripened pollen tassels onto the home's roof, then to the valleys, then it was forced down to the drive itself in heavy concentrated clumps. All the pollen from this huge oak was concentrated onto the drive in a 12 by 12 area.

I got it up the next morning but it was too late. It had already been wet and bled out dark brown stain. Tried pressure washing (3000psi) with a little bleach but it doesn't even faze it. Any suggestions?

 

I call it "patina" and it is much easier to just live with it than fight it too much. If the area gets sun the stains will be bleached out in time for it to happen again next season.

 

It's called Tannin stains.
Sometimes a paste of Oxiclean brushed on and let sit for a while then hosed off will float it out of the pores.

 

Thanks for these replies. I too expect it to fade away but potential home buyers are picky and will probably make me deliver it clean enough to eat off of.

 

Stain the rest of the driveway to make it uniform?

 

It sounds like you are cleaning off your driveway pretty regularly. I think that is the best you can do. I have a large amount of concrete driveway, wood decking and white pea gravel walkways close to all sorts of trees. They all get some amount of tannin stains but none have ever been permanent but as old stains fade away a new leaf blows in to create a new one. Is your concrete new? My concrete is several years old and well cured. I'm wondering if fresh concrete is more susceptible to longer term staining.

 

The concrete is about 16 months old. It's a spec house that continues to sit because of the economy. Typically the tannin sacs fall well away from the drive but because the hailstorm came westward, it drove the tannin sacs to the drive and stained it. If I can get this staining up it won't happen again under normal conditions. The occurrence was a rare event.

 

Did you try scrubbing it any when you pressure washed? A little detergent and an old broom might do it.

 

No, but that's my next attempt.