Many and varied are the enticements to visit Grow London Contemporary Garden Fair but Hampstead Heath itself is part of the attraction offered by Kim Walker and Vicky Chown, the herbalists of Handmade Apothecary.

As well as running a make-your-own home remedies and cosmetics workshop in the marquee at the Heath’s lower fairground site, they will be leading an educational Herbal Heath Walk across Prior’s Field.

I met with them to get an idea of what visitors can expect. It was a fine early June morning so nothing could have been better than to set out among the long grasses and buttercups, pausing to consider the virtues of meadowsweet or plantain, elderflower or lime blossom, clover or nettle.

Whether stepping out on Friday (June 19) will be equally fine remains to be seen, but even in rain it would still be an interesting way to approach a stretch of grass most people probably walk over without thinking twice about what lies at their feet.

Vicky and Kim say that Hampstead Heath has become richer in plants interesting to herbalists since the policy of less frequent mowing came in.

The patch of meadowsweet at which we stopped might previously have been mown before it could go to flower, thus precluding the flowering tops being made into “a good digestive tea” or used as an anti-inflammatory. (Not that we should be picking anything – the Heath authorities are clear that the walk should not be an invitation to forage.)

Elderflower was full out and scenting the air as we walked, while the lime blossom had yet to open. We stopped to taste some elderflower cordial that these well organized apothecaries had made and brought along, and talked of the stress relieving properties of lime blossom tea.

As an aside, Kim explained the design of the tisane cups you can buy in countries like Switzerland where people drink a lot of herbal teas. These cups have a lid as well as a fitted strainer, which is not just to keep the tea warm, but to stop some of the virtue of the tea from evaporating.

As well as the elderflower cordial (against hay fever) Kim and Vicky had also brought plantain chips – not the yellow ones made from the banana shaped plantain, but green ones made from the leaves of the plantain we think of as a lawn weed, Plantago lanceolata. Paper thin and crisp, they tasted somewhat of seaweed.

The plantain we found on the Heath that day had bigger leaves and was, said Vicky, probably Plantago major.

If the term herbalist brings any image to mind, I doubt it would be of a young woman. But both Vicky and Kim are thrilled by botany and herbalism and, clearly, very knowledgeable.

I asked how they had arrived at their current occupation. the answer was, from very different childhood experiences. They met at Westminster University where they were studying herbal medicine, having both at different times worked for Neal’s Yard.

Vicky says she was brought up on microwave meals in Palmers Green in a family with no great interest in plants, but that she came to them via a fascination with magic.

Kim, meanwhile, grew up in Argyll, where her grandmother had a smallholding and made herbal remedies.

Now they share a love of herbalism’s blend of science, folklore and history, they also share a canal boat, and botanize along the tow paths. This boat, currently in need of restoration, they hope to rename The Floating Apothecary.

Meanwhile, on dry land, they will be well worth visiting at the fair.

Check growlondon.com to see when this weekend’s free Handmade Apothecary events will take place.