Are any plants tough enough to live on the surface of a driveway?

Question

A lot of driveways around here are two-thirds planted with two hard wheel tracks made of cement blocks or cobblestones. I like the permeability and decoration that goes into them. Our off-street parking space has access only from the side, therefore there is no direct path in and out, rather it's a parallel-parking situation.

Are there grasses that might put up with a car tire occasionally crossing over? I know plants don't generally like to be driven over, but there must be some that are more tolerant or resilient than the rest, probably flexible ones that can lie flat and stand back up.

I'm interested in planting inside some kind of rows or matrix of hard material over which car tires would pass. Keeping the loose earth just below the driving surface might prevent a mud bath. Is this scheme viable?

My location is San Francisco, California.

Answer 1

Two critical factors are sun/shade and soil type. I have a long driveway to my place with some areas in sun, some in shade and mostly sand and sandy loam soil. In shady places traffic wears the surface to bare soil, with mossy occasional grass growing between the tire tracks, so nothing survives. In sunny parts the natural invasion of quack/couch grass (Agropyron repens) intermixed with dandelion and white clover (Trifolium repens) survives light traffic very well. In extremely sandy places oddly it is the Rough Cinquefoil (Potentilla norvegica) which does best even when mowed down hard.

Soil type is important - I once spent an hour trying to get my vehicle off an inclined clay surface after a heavy dew. The soil turned to slick, oily mud which would have been no problem for a half-track. Sandy loam usually has no problem if it has a chance to drain, but persistent rain can lead to surface accumulation and then the matted roots of quack grass cannot maintain integrity when attacked by various utility employees with a heavy foot on the gas. In deep winter of course the road is not passable by regular vehicles due to snow and ice accumulation but in SF that is not likely to be a problemo.

Combined with cement blocks on end of course, quack grass will be unable to spread sideways so clover might work. In SF, look to what grasses are used in sports fields locally and how they stand up to hard wear. Occasionally fields are subjected to joy riders in 4x4 vehicles; the results are a severe test of plant materials.

Answer 2

Because you don't have particularly cold winters, you actually have lots of options for growing grass within/through pavers: Grass block pavers That article actually references a Bay Area site; it also gives examples of different types of pavers and instructions on installing them - the underlayment is not soil, but a pretty typical paver base.

This UK site shows you more options for types paving systems:Grow-through paving. I would expect that a reputable landscaping company (not two-guys-with-a-skidsteer) would be able to give you more details and help with sourcing the paver system.

If you're more interested in a less expensive option, then note that the first link gives you ideas for grasses to use - but in that case, take Colin's advice to heart about soil type and note that with each pass of the car you'll be compacting the soil. Eventually, only noxious weeds like prostrate spurge, prostrate knotweed, and plantain will grow there.

Answer 3

Plantago genus, common name plantain (not the banana) grows as a weed on roads and can be driven over.