A Juniper and a Patio

(Question)

I live in the Innisfil area and I have a massive juniper growing beside my front porch. We need to fix our walkway to the front steps BUT immediately under the patio stones are the juniper roots. Is it safe to redo our walkway (more soil or gravel to raise it back up) or would it harm the juniper?

(Answer)

Thank you for contacting the Master Gardeners with your question.

This is a bit difficult to see from the picture how much of the roots are impacted by the patio stones. So I will respond in more general terms to say that it is a matter of degree of how much of the juniper’s root system will be impacted by the walkway.

Although there are many variables, first I would assess the amount of roots being impacted by the walkway.  If it is a higher percentage (say more than 25 %) of the shrubs root system, then it might give rise to the question of how to mitigate root damage.  Limiting the amount of added soil or gravel by possibly removing and replacing , rather than building up additional weight would be helpful. Also try to avoid limestone screening and instead use pea gravel which have less an impact on the soil PH. It goes without saying to try to limit damaging roots as much as possible with the excavation equipment or tools.

Also try to improve overall soil conditions, by adding triple mix around the shrub, and also fertilize (usually done earlier in the year, now it is borderline getting a bit late in the season to fertilize junipers).

Best of luck with your new walkway.