Mercer County Master Gardeners will offer an “Open Gardens Tour” from 11 a.m. to 4 p.m. July 21.

Tickets are $10 per person for all four gardens, and are available at the Mercer County Extension Office or at the gardens:

• Devonshire residence at 146 Andrusky Road, Mercer. This location will feature a complete collection of Stout Medal winners, the highest award given to daylilies. There are very few complete collections, and this collection has been used by the Brooklyn Botanical Garden. Called “The Summer Place” by the Hemerocallis Society, the Devonshire property was designated as a display garden because of its display of the very best daylily cultivars. There are about 500 daylilies throughout the property, which create a common thread throughout the garden. There is also a complete collection of the Hosta of the Year. The hostas complement the lower garden and surround the home. There are thousands of daffodils and 175 lilac bushes, including many featured in Father Fiala’s reference book, “Lilacs: The Genus Syringa.”

• Maybray residence at 172 Andrusky Road, Mercer. The Maybrays started with a hosta garden and later joined the Daffodil and Hosta Society of Western Pennsylvania when they started collecting different cultivars, which now number more than 300. There are also several daylily beds, a small pond filled with pond lilies, pickerel weed, irises and lotus, as well as a carnivorous bog garden. The property also features a collection of arisaemas, with species from Japan and China.

• Stigliano residence at 626 Robertson Road, Hermitage. Their various vegetable gardens complement the beds of flowers surrounding the work shed, front yard, stream and pool area.

• DJ’s Greenhouse at 1004 East Lake Road, Transfer. This location features hosta, fern, irises, daylilies and hundreds of other perennials and wood ornamentals. The new rock garden features sedum, conifer and a large assortment of different plants. Info: 724-662-3141