There is still time to sign up for master gardener classes

Nevada Cooperative Extension is starting a new master gardener series. For those interested, there are still a few spaces available. Fall classes meet on Mondays, Wednesdays and Fridays from 9 a.m. to noon, beginning Sept. 7 at the University of Nevada Cooperative Extension, 8050 S. Maryland Parkway.

Master gardeners are dedicated community volunteers. To become a master gardener, an applicant must complete 70 hours of horticultural instruction, pass a comprehensive examination and volunteer a minimum of 50 hours of public service each year through the Cooperative Extension program. There are more than 200 active master gardeners.

The class is open to people of all backgrounds who have an interest in gardening and volunteering. The Cooperative Extension charges a fee of $200 to cover the cost of books, training materials and refreshments. Your fee is payable at the first class.

The program's informative training will provide the skills needed to diagnose plant problems. You will have the opportunity to work with schoolchildren, teachers, seniors, community gardeners and homeowners. Being a master gardener volunteer is fun, interesting and rewarding.

For more information on this nationwide volunteer program or the fall class, contact Ann Edmunds, program coordinator, edmundsa@unce.unr.edu or call 257-5587. There also is a hot line at 257-5555 for them to answer your gardening questions.

Here are a few of the many questions I answered this past week:

Q: We converted our lawn to xeriscape and now the pepper tree left in the lawn area has several side-limbs shedding leaves, but the tree's top-growth is doing fine. What is happening?

A: You removed many roots where the tree was getting water, but you didn't disrupt the lower roots supplying water to the top growth. The side limbs will continue to thin out until the tree roots make adjustments. In the meantime, remove the deadwood.

Q: How can I sign up for the Water Smart landscape rebate?

A: Thanks for wanting to save water, but many of you call me by mistake. You need to call 258-7283. The Southern Nevada Water Authority will rebate customers $2 per square foot of grass removed for the first 1,500 square feet. After that amount, you will get $1 per square foot. You must participate in a preconversion site visit before removing your lawn; otherwise you become ineligible for the conversion. Statistics are showing that for every square foot of grass replaced with water-smart trees and shrubs, an average of 55 gallons of water per year is saved. And you save on your water bill.

Q: Why won't my large potted lantana plant bloom? It is getting plenty of sun and I fertilized it.

A: It is a good sign the plant is stressing for water, especially when it is in a pot.

Q: Is it safe to add 18 inches of soil around the base of my mulberry tree?

A: I'll say not. Piling soil on an established root system suffocates them, and you can't replace a mulberry. It may take a year or so to kill it, but it will happen.

Q: Why won't my bougainvillea bloom? I water them every day. I see them blooming elsewhere.

A: The key is watering every day; bougainvilleas love neglect, so back off the water. I recall taking a ride through the abandoned homes near the airport and the plants there were in bloom. They were breathtaking, and none had been watered for a long time.

Q: Why are my junipers turning brown and dying? I wonder if I am watering right.

A: Spider mites may be sucking sap out of needles, causing the browning. Wash plants down to dislodge mites so they dehydrate. Overwatering causes yellowing and root rot.

Q: Why won't my oleanders bloom? They are in their second year and bloomed once this spring.

A: A lack of water is the most likely factor. One of my emitters plugged and the oleander stopped blooming, so water more. Removing too much of last year's growth prevents blooming.

Q: Will a magnolia tree grow in Las Vegas?

A: The magnolia tree struggles in alkaline soils, low humidity and high temperatures, and it needs water with those large fleshy leaves. To overcome these problems, add sulfur to the soil every spring and an acid-type fertilizer such as ammonium sulfate with every feeding.

Q: I have an ash that has leaves turning brown around the edges and moving inward. What is this? It does not look healthy.

A: When tree leaves turns brown as you describe, it usually indicates the tree needs more water to push away the salts from the root zone. Watering deeper will solve this problem.

Q: How do you prune a hibiscus?

A: Not much needs to be done during the summer except redirect vertical growth. This winter, cut back last season's growth, leaving several buds on the canes. Never prune it into squares or globes; it's always prettier in its natural form. During the winter, reduce watering and protect it from cold winds to increase your flower production.

Q: We planted Queen Elizabeth climbing roses that were labeled "ever blooming." After the spring flush, we haven't had any buds, yet the plants appear healthy. Why won't they bloom?

A: According to Dick Jackson, the plants are building strong canes for roses in the future, so you will be OK next year.

Q: Can I prune back my ocotillos and will they grow back up?

A: Do you really want to? One of the beauties of the ocotillo is its long, straight canes. Chopping them back causes them to fork and take away from the silhouette of the plant.

Q: My autumn sage looks so shabby, how can I spruce it up?

A: Right now, spruce it up before the fall flush of growth. For optimum flowering, prune autumn sage just before the spring and fall flushes of growth by cutting off old flower stems to the green area to stimulate new flowering wood.

Q: How can I get some cuttings from my daughter's sheffelera plant?

A: Take several 12-inch cuttings from branch tips with leaves still attached. Dip the bottom-end of cuttings in root hormone sold at your nursery and plant in moist potting soil. In a few short weeks, you will have yourself some new plants.

Linn Mills writes a garden column each Thursday. You can reach him at lmills@reviewjournal.com or at the Gardens at the Springs Preserve, 822-7754.