Q&A: You’ve been watering your trees all wrong: A drought expert explains how to get it right


As the botanical information consultant at the Los Angeles County Arboretum & Botanical Garden, Frank McDonough says it’s his job to introduce people to a variety of plants and solve their gardening dilemmas. On Saturday, McDonough will tackle Southern California’s biggest dilemma of all -- how to save water during the drought -- as he shares water-saving strategies that you can implement at home.

During the tour of the arboretum grounds, McDonough will highlight appropriate plants for the Southern California landscape, rain-capturing methods, irrigation systems and lawn replacements. “We’ll walk around the arboretum and look at all the different ways to save water,” says McDonough. “We have been on top of this since the ‘50s. We have a great collection of plants from South Africa, Australia and the Mediterranean.” McDonough also plans to make a stop at the Inter City Cactus Show and Sale and offer some suggestions on plants to take home. And if it gets too hot, don’t worry. McDonough is prepared to hold class underneath a shady tree with his Android tablet. Here, he offers a preview of what to expect on Saturday:

What is the arboretum doing to save water?


We’ve always been saving water. Most of our South African and Australian plants get watered once a month. We’ve shrunk our lawn area and removed the lawns that are unnecessary. In 2001 we instituted a mulching program that has helped save a lot of water. It also saves pesticide use and has decreased our use of herbicides down to nothing. Weeds are big water wasters. Think about it: If you remove the weeds surrounding a tree, then you’re just watering the tree. Recycled rainwater is used to irrigate our vegetable garden. I will discuss the pros and cons of drip irrigation on the tour. There are instances where you can use a drip system and those where you can’t.

How much water do our gardens really need?

The typical Southern California landscape only requires watering once a week. People have been overwatering their landscape since the ‘60s. I think it’s because a lot of people aren’t from here and they are used to compulsively watering their landscape. If people watered the way they should, we probably wouldn’t have the drought issues we have today.

Can you share some of your favorite drought-tolerant plants?

I really like aloes. Rooikappie (‘Little Red Riding Hood’) is one of my favorites and it blooms all year long. A more esoteric favorite is the Matilija poppy. Here is a trick I discovered to help grow them: Plant a shallow rooted monocot around the base such as society garlic or agapanthus. The plants will keep the soil around the roots cool and moist. I was able to keep them blooming until October and they were irrigated only once a week. They have the most amazing smell in the afternoon. I think they smell better than roses.

What about trees?


Trees fail a bit in the summer. Most people don’t realize that watering trees is not as complicated as it seems. Use things like irricades, a traffic barrier promoted by Tree People. They are great for irrigating trees. Fill it with water and it will slowly irrigate the tree over a few days with soaker hoses. You can also add a basin around the tree and fill that with water. Watering basins are fashioned from soil to form two concentric ‘berms’ or lips that hold water. The inner lip is 4-6 inches tall and about as wide at the base and encircles the trunk, leaving about 4-6 inches from the top of the berm to the beginning of the trunk. The second berm is fashioned in the same manner to form a ‘basin’ that encircles the tree at the outer edge of the trees canopy, an area also known as the ‘drip line’. That works for two to four weeks. Keep in mind what kind of tree you have and what it needs. Trees should be watered on a less frequent basis than a lawn or a garden.

What does the landscape of the future look like?

Go to YouTube and type Atilla’s garden and you will see what the future looks like – an Australian succulent garden composed of plants from all over the world.

Frank McDonough will lead a walk through the Los Angeles County Arboretum & Botanical Garden on Saturday at 11 a.m. The tour is free with admission of $4 to $9 and free for members. The tour will meet at the gift shop patio and repeats on Sept. 19. The arboretum is also offering a new Crescent Farm water conservation project that provides hands-on water saving training for home landscapes. 301 North Baldwin Ave., Arcadia. (626) 821-3222.

Twitter: lisaboone19



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