By Nancy Hawkins
UCCE Master Gardener
At our Master Gardener Demo Garden at Hurley School, we are focusing on Gardening Central Valley Style by demonstrating a variety of gardening styles and methods while advocating sustainable gardening practices. We educate the public and ourselves by showcasing certain types of plants, irrigation systems, pest management techniques, and/or landscape designs suitable for our area. At this site, we have eight beds, from veggies to ground covers to succulents. Each bed focuses on efficient irrigation and water-wise plants. We are watching each bed carefully to see what survives and what doesn’t do so well.
We’ll share our insights Saturday, May 4, 10 a.m. to 2 p.m. at Spring into Gardening 2019 at the school, 6600 W. Hurley Ave. Water conservation, even after a high rainfall year, is an ongoing concern for Central Valley gardeners. Lawn removal or reduction is a major way to reduce water use at home. Because we get many questions on what to replace lawns with, two of our beds are devoted to lawn-replacing, and low-water ground covers. Three of the ground covers chosen were: Yarrow (Achillea ssp), Frog Fruit (Lippia nodiflora), and Creeping Thyme (Thymus ssp). I knew little about these ground covers, so I thought some research was in order.
Here is what I found: Achillea, or yarrow, is a California native well adapted to our area. It loves heat and sunshine. The cultivated varieties have become staples in gardens because of their tough nature, ease of growing, and beautiful flowers and foliage. They will spread rapidly by underground roots, making them great filler plants or lawn replacement plants.
The species we have at Hurley School is Achillea millefolium. It has dark orange-red flowers and soft, feathery, aromatic foliage. It will grow to be six to 36 inches tall (depending on how it is trimmed) and a single clump can spread 12 to 24 inches. Yarrow blooms repeatedly throughout summer. For the most blooms, keep the plants deadheaded. Don’t be hesitant about lopping off the spent flowers, they will set more buds quickly if you do, and the plants will stay full and bushy.
Yarrow is tolerant of most growing conditions, but it does best in a well-drained soil. Yarrow plants are easy to find in most garden centers and are also available as seeds. The best time to plant is in the spring, to take advantage of the cooler temperatures and rain. But yarrow is a tough customer and can be planted or moved at any time, as long as you give it some extra water while it gets established. Yarrow is low maintenance. In ideal growing conditions, yarrow can spread rapidly, although not aggressively. Watch carefully to make sure it doesn’t spread to where it is not wanted! Divide every two to three years, as needed.
Frog Fruit (Lippia nodiflora), despite its funny name, is not a fruit for frogs. This small, prostrate, spreading, evergreen perennial has serrated green leaves and blooms from spring through fall. It is widespread in tropical, subtropical, and warm temperate regions. Frog Fruit tends to stay close to the ground, reaching a height of 3 to 6 inches. However, in wetter, shady conditions or when given additional water, it tends to be more upright and can attain heights of 8 inches. The bloom clusters are round and compact, measuring about 0.5 to 0.8 inches in diameter. The tiny blossoms open in a ring and vary in color from pale pink to white. Despite their soft appearance, the leaves of Frog Fruit tend to be stiff and have distinct serrations around their edges.
In our area, Frog Fruit will remain green all year long. It spreads rapidly in the spring and summer and will take over a garden area if not watched. The good news is it is easy to trim or cut back, and hard to kill. Frog Fruit prefers moderately fertile soils but will grow in soils with lower fertility. It has a preference for sunlight, growing more vegetation and fewer blooms in shady areas. Even though it is drought tolerant, it does much better with regular watering in our hot summers. In addition to its use as a ground cover, Frog Fruit is a good nectar plant for butterflies, and it is an attractive plant rambling over a boulder, or the edges of pots or hanging baskets.
There are many varieties of Creeping Thyme (Thymus ssp.) that can be used as lawn replacement ground covers or among stepping stones or pavers to create a living pathway or patio. They are evergreen, with tiny pink or white flowers, and grow in low, dense mats that quickly fill in areas as a ground cover. All are easy to grow in our area with fairly minimal requirements. Creeping thyme can be propagated via stem cuttings or divisions and can be purchased from nurseries as either established plantings or seeds. Creeping Thyme does well in sunny beds, borders, rock gardens, and spilling over rock walls. Once it is established, it is fairly drought tolerant. Creeping Thyme plants are tough enough to handle some light foot traffic. Rabbits and deer do not bother it. Creeping Thyme self-sows readily, dropping seeds after its flowering season. This keeps a robust stand of this ground cover thriving. In the fall, it can be sheared back to tidy it up. As bonus, dried thyme can be used in cooking and teas.
The UCCE Master Gardeners will be available to answer your gardening questions each Saturday at the Visalia Farmer’s Market in the Sears parking lot from 8 to 11 a.m.