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Nan Sterman, local gardening expert and host of “A Growing Passion,” shooting a segment on how Rose Parade floats are designed, built and covered in flowers. Courtesy photo
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Nan Sterman shares her passion for plants

If you have a garden, you’ve most likely heard of Nan Sterman. Or seen her on TV on “A Growing Passion” on KPBS. Or read one of her columns or books.

You might have even taken one of her classes.

Sterman wears many hats in the local gardening community, and she is spreading the seeds of her knowledge in any and every way she can.

Gardening has been a part of her life for as long as she can remember, but she didn’t plan on making a career out it. “I gardened as a kid with my grandfather,” Sterman said. “Or he mostly gardened and I rolled around in it.” When it was time to go to declare a major in college, an idea sprouted that she hadn’t expected. “I surprised myself by majoring in botany,” she said of her time at Duke University. “That background allows me to understand the world of plants differently than most people. I take a science-based approach.”

Following her first graduate degree in biology from UCSB, she studied at SDSU and earned a second graduate degree in training and education development. “Understanding science and how people learn and communicate, that intersection is where I am,” she said.

Her science background leads her to get to the bottom of gardening myths that many just accept as being true. “There is a lot of misinformation out there,” she said. “I always say, ‘Wait a minute, where is the research to back that up?’” She touted the wide use of Epsom salts in gardens as an example. “You definitely don’t want to use Epsom salts,” she said. “Where does that come from? It’s a salt. And I don’t want to put salt on my soil!”

While Sterman’s wealth of knowledge and experience is useful for anyone, residents can benefit her knowledge of local plants as well as experience her extensive, hands-on seeding workshops. “I spend two-and-a-half hours starting with how to read a seed packet and how to know what to plant and when,” she said. “They literally plant their entire garden and take it home with them.”

As we enter spring, Sterman has specific tips for gardeners. “The first rule of thumb, when it comes to edibles is that spring is the second season for planting,” she said. “You really want to plant in fall for ornamentals. If you miss that window, spring is the second season.” Generally, if you eat the leaves and the stems, she said that is a plant you grow in cool weather — fall, winter or early spring.

“If you eat the fruit, you want to grow that for the summer harvest,” she said. “Peppers and tomatoes are technically fruits, as they have seeds.

Cucumbers, squash, melons — all those things. Except for beans and peas, which do better into late spring and early fall.”

Sterman also said that spring is a great time to check your irrigation system. “If you have not yet converted to an inline drip system, this is the tim e to do it,” she said. “The emitters are in the tubing instead of around the garden. You want to apply a thick layer of mulch, 3 inches minimum.” This is especially important for the summer, when we have to be more careful about managing water. “Mulch is the best way to do that,” Sterman said. “Mulch is like an insulating blanket. When you have moisture in the soil, the water stays in the soil instead of evaporating into the atmosphere.”

When it comes to inline drip systems, Sterman has plenty to say as to why it is the sensible choice for irrigation. “It is the most foolproof and efficient of the kinds of irrigation you can use,” she said. “You want to put down that irrigation, and mulch over it. You want the irrigation on the surface of the soil, the mulch over it and when you water let it run a really long time because the best, strongest way for plants to grow is through their roots. You want water to go down a foot or more.”

She urges gardeners to reconsider using sprinklers. “You don’t want to turn on the sprinklers for five minutes a day,” she said. “Irrigate once a week or month, depending on whether the roots are established.” She said that people tend to overwater, and that overhead sprinklers are, well, inane. “They make no sense,” she said. Plants need water in the soil. The roots are what use water. They pull from soil and circulate up into the plant. We need water in the soil, but we spray it in the air. What we really need it to put water in the soil. That’s why I’m proponent of inline drip irrigation.”

Just how long does it take for roots to establish? “It’s like when you move to a new neighborhood, you have to adjust,” she said. “Kids adjust faster, and small plants adjust faster than big plants to being planted.” And while the roots are being established, they need extra care. “While the roots are establishing you want to water more often, not for longer periods. Once established, you can cut back.”

Asking a plant person of Sterman’s caliber about her favorite plants is like asking a mother to choose her favorite child. But she is a big fan of the pineapple guava, which does very well locally. “This is an edible, permanent plant with a wonderful big shrub with cool flowers of pink and red,” she said of the plant, which is not a true guava. “The petals are sweet; you can pick them off gently to decorate a dessert. It’s one of those plants that every family with little kids should have. The fruits are so cool, and kids have fun picking them up off the ground and eating them.”

Not all plants are loved equally, and flowering shrubs are one category Sterman considers underrated. “People think of flowers, they think of annuals or perennials,” she said. “Flowering shrubs are a great constant solid background that keep the garden looking good while other things come and go.” Two of her favorites are the Australian and South African shrubs. “Grevillea shrubs can be as tall as 15 feet or 1 foot tall and really wide,” she said. “They make wonderful, curled flowers and the hummingbirds go crazy for them. They bloom primarily in the fall and spring and have a great texture even when they aren’t blooming.”

Leucospermum, or pincushion, shrubs from South Africa also top her list. “They make flowers that are baseball to softball size and they look like a pincushion,” she said. “They have shades of yellow, parts are red, parts are pinkish — all different color combos.” These bloom from January through March or April. They have wider leaves, and Sterman suggests they make a great hedge. “They make great screens if you want to hide trash cans or ugly views,” she said.

Sterman has other helpful tips for making the best of what you have. “Plant edibles in raised beds or big pots,” she said. “Growing plants, especially for edibles, you have to have big pots. As big as you can get. You can fill a pot with whichever soil you choose. You can water all you want, and use all the rich fertilizer.

Sterman also advises to make sure you’re getting gardening advice that applies to the region in which we live. “We have a Mediterranean climate,” she said. “We don’t get our rainfall in the summer. Every other type of gardening region in the world rains when it’s warm, so you have completely different plants, you do things differently, the soils are entirely different. You have to garden where you live.”

Sterman has two upcoming seeding workshops one March 26 and another April 2. To learn more about her upcoming events, projects and appearances, visit her website at