Church bells rang out, echoing across Colombia. People held signs in the streets and posted exuberant messages online: the last day of the war.

That day last month, when the ceasefire was signed, could have been the last day of the war, but a piece of paper is no guarantee. Realising the ceasefire’s promise – lasting peace – lies not in the final agreement but in grassroots activism.

Big questions need answers. How will we ensure that demobilisation and weapons handovers happen without violence? How will we provide care and counselling to people who bear the physical and emotional scars of the war, including an estimated 13,600 survivors of sexual violence? How will we reintegrate combatants, especially thousands of soldiers forcibly conscripted as children, into communities still wary of them?

Grassroots female peace activists have not only anticipated these questions. While war raged, they seeded their answers into embattled communities and into the peace process.

During negotiations between the government and the Farc rebels, female peace activists pushed for the right to participate. Their years of aiding and protecting communities on the frontlines of war gave them a distinct vantage point. Better than government officials or rebel leaders, these women could speak of the needs and demands of their communities.

They sounded the call for action against rape as a weapon of war. They prioritised it in their advocacy and brought survivors to address the peace talks. These women struck a blow against impunity by ensuring that sexual violence was included among the crimes denied amnesty.

This victory means that survivors have the chance to pursue legal justice against their perpetrators. What’s more, it sends a message: sexual violence is a serious crime, and we will confront it.

Far from the talks in Havana, women have sowed peace in frontline communities for decades.

Women have set up peace enclaves (pdf), where combatants temporarily laid aside their arms and limited ceasefires held. Women’s groups created spaces for public gathering and dialogue, helping to integrate people displaced by war into the communities that received them.

Now, as Colombia’s official peace process wraps up, we believe these community ties will form the basis for lasting peace.

To demobilise combatants, the government plans to set up target zones, where rebel soldiers will lay down their weapons and re-enter civilian life. The stakes are high. It takes a lot of trust to give up your weapon to a former enemy, especially without assurance that the community will take you back. Everyone is haunted by past failures: in the 1980s, an attempt to demobilise the Farc into a political party fell apart and 3,000 members were killed in reprisals.

But today, women’s groups are using their expertise and networks to secure a better outcome.

One of the demobilisation zones will be set up in a Pacific coast area called Chocó. Local organisation Taller de Vida is already there, holding community discussions and running support centres for former child soldiers and war-time rape survivors. Taller de Vida uses the arts as a form of therapy that does more than promote individual healing.

Through art installations and public gatherings, former child soldiers and rape survivors share their stories of healing and hope. These encounters re-weave the same ties that war tears apart, fortifying the community to become more resilient to outbreaks of violence.

Art therapy and peer counselling activities offer survivors a chance to reinvent themselves and escape stigma. They enter a safe space where they are encouraged to tell their own stories, through song, spoken word, writing or drawing. Crucially, these interventions help pivot them away from the past, prompting participants to spell out the future they want for themselves and their country.

For former soldiers, especially those recruited as children, civilian life is the new jungle. They will be dislocated from the armed groups that were their only home. For peace to take root, communities will need to accept these former combatants. And they will need to learn how to manage their own lives, without a commander’s orders. Taller de Vida offers financial training to help former child soldiers manage the payment they get from the government, and also supports groups where former child soldiers can talk openly.

True peace is seeded and cultivated at the grassroots. On 20 July, the date for the signing of the final peace agreement, we won’t mark an end. We’ll mark a beginning of the work of growing peace – fraught and fragile, but closer than ever to blooming.

• Stella Duque is executive director of Taller de Vida