How does one build a bluestone paver patio with grass between the stones?

Question

The plan is to use 2'x2' bluestone pavers with up to 3" of space between the stones. This would be placed on a base of 6" of bluestone dust (as this has been more effective than natural screenings/fines at keeping ants from taking up residence).

I would love to have grass between the stones, but I'm concerned that the 2" deep won't be enough soil.

Is this enough soil for grass? What are some considerations to help ensure success? Is this a long term solution? Will the grass cause the stones to shift/lift over time?

Do you get long hot summers? How much foot traffic do you expect? Are you okay with having to mow the grass on the patio? — kevinskio, Sep 04 '15 at 15:58

score 3 · Accepted Answer · edited Apr 13 '17 at 12:42

I am not big on grass in areas where people will sit. There are many other plants which will do a better job of being green and requiring little or no maintenance.

two inches of soil is a bit thin for grass. You will find the slabs radiate heat absorbed during the day and dry out the soil. You will end up having to irrigate during the summer and may see dieback during the winter.
the grass will not push the slabs out of place but will tend to mound up between the slabs as they create more organic matter
you will have to cut the grass in the summer and unless you are scrupulous about using a mower with a bag the clippings can be a bit messy. If you mow low to get the look then the grass will be stressed in the summer and you mow high then it doesn't look very good.
Irish moss will do a much better job particularly if there is a bit of shade

Your Irish moss link goes to a disambiguation page for 6 different plants. Based on growth habit I'm guessing you mean this one: http://www.wikiwand.com/en/Sagina_subulata — GardenerJ, Sep 04 '15 at 16:26

score 1 · Answer 2 · answered Sep 05 '15 at 19:15

That Idiot, grins! I would NOT do grass. Wooly thyme would be my choice! Greyish, no maintenance...keep the size of seams between flagstones as CONSTANT as you can. DO NOT cut flagstone to fit. Fit the flagstone as best you can. You should have 3-4" of compacted gravel with at least 1" of mason sand compacted on top before placing flagstone. Place flagstone (this is an ART) then fill seams with 1/2 sand and 1/2 POTTING SOIL. Then plant tiny starts of Wooley Thyme. Soft to walk on! The grey green goes with the flagstone (usually)...grass will look like WEEDS. Grass works ok between large flagstone PAVERS that have seams at least 3-4" and those are usually CUT IN to an established lawn body. The sun in summer can truly fry grass. Ugh. Wooly thyme is tougher than grass and grows out over the flagstones as well. You'll have to keep an eye on your thyme to make sure it gets regular water. Not a lot as this is a pretty tough plant. At first you'll have to water lots more, later hardly at all. Do you have a picture of what you are trying to do? Please post that so we know what we are talking about...!

How does one build a bluestone paver patio with grass between the stones?

2 Answers2