Wouldn’t it be great to have plants that only have to be planted once and bloom for a long time? If you choose well, there are many perennials that can fill the bill here in the Central Valley. There are perennials that bloom almost all year long, are untroubled by pests and diseases, and add fresh flower form and substance to your garden.
But what exactly is a perennial? In California, it’s complicated. What are called perennials in California are plants that live longer than annuals, but are not as sturdy or woody as shrubs. Many gardening books call them “herbaceous” perennials, reflecting how the plants behave during cold weather: they die to the ground each winter and come back (produce new growth) each spring. Be sure to seek western sources for information on perennials because eastern varieties may not thrive here without winter chill. Local nurseries can provide information on California natives and drought-tolerant plants and are displaying many perennials right now.
To get you started, here are a few favorite perennials that have stood the test of my own Visalia garden for several years. If you’re looking for a short perennial that blooms almost year round, consider Scabiosa ‘Butterfly Blue.’ It grows only a foot tall, has round flowers that resemble a pincushion, and are very attractive to butterflies. To keep them blooming, cut off spent flowers down to the next joint, where you will see new flowers coming. If they get away from you, you can cut off the entire bloom stalk, fertilize, and let them send up new blooms.
A hot colored perennial that could also replace annuals in flower production is Gaillardia ‘Goblin.’ Daisy-like flowers with a red center and red petals tipped in yellow provide a near year-round show on this compact foot-tall plant. Other varieties tend to sprawl across the ground and hence “blanket flower” is its nickname. Again, deadhead to extend the bloom.
A slightly taller plant at 18 inches is Achillea ‘Moonshine’ which has silver foliage and pale yellow flat-topped flowers. Another good Achillea is ‘Coronation Gold,’ which grows to three feet and has bright yellow flowers. Achillea millefoliums are also good bloomers but they sometimes need some support staking and can spread a little too freely!
Echinacea or coneflower grows to three feet with pink or white daisy-like flowers. Penstemons and salvias are also lovely long blooming perennials in Valley gardens and they do best with less water. The hummingbirds will love you if you plant them.
In time you will need to divide your perennial, digging it up and dividing it into several fresh new plants to replant in your garden. Close inspection reveals perennials are actually composed of many tiny plants growing in a clump together. By separating them and planting them in newly amended soil, you give your plants a fresh start and multiply them at the same time.
Perennials can be planted in fall or spring. These plants will be in place a long time and require a good rich soil to perform best. Dig up the area and add several inches of compost or other soil amendment and a handful of fertilizer. To keep your plants blooming as long as possible, study how they bloom. Cutting off spent flowers at the base or along the bloom stalk should force other buds to open. Some plants, like Shasta daisies and salvias, grow fresh new foliage at the base of the plant when the old foliage starts to look too ragged. Cut back to the fresh growth, fertilize, and you have a rejuvenated plant. Plants like penstemons can also be cut back to encourage a flush of new blooms. Through deadheading and cutting back, you can keep your perennials in bloom a long time and enjoy their show through many seasons.
Purchasing plants and supplies: At the nursery, choose the plants that will form the foundation, the color bursts, the textures, the diversity, and the unifying elements to your beds. The more you mix, the less formal the effect. The more you match, the more formal the effect.
We suggest that you choose plants carefully for our summers in the valley and foothills. Try to select plants that have matching irrigation requirements and try to select drought tolerant and water thrifty plants. There are many perennial herbs and flowers adapted to our Mediterranean climate that are underutilized and are being showcased in nurseries right now. Every plant we talked about today is pretty thrifty on water use requirements, yet they provide an abundance of bloom and interest.
The Master Gardeners will be live to answer your questions at two upcoming events: April 10, 10 a.m. to 2 p.m. at Luis Nursery in Visalia; and May 1, 11 a.m. to 2 p.m. at Ace Hardware in Visalia. You can contact them at 559-684-3325. Or visit their web site at ucanr.edu/sites/UC_Master_Gardeners.