Peonies need a long winter chill to thrive

Here are answers to some of the questions that came across my desk this past week:

Q: We were in Salt Lake City on Memorial Day and fell in love with peonies. Can we grow them?

A: Peonies do well when they experience a period of pronounced winter chill; we seldom have that here, so that is why you don't see them. However, there are folks who plant them in pots and take them to friends' homes at Mount Charleston for the winter and bring them back in the spring. If you do decide to try them, it takes two to three years before they begin flowering. I doubt you'll find them in our nurseries. If you know of someone going to Utah, have him or her bring some plants back for you. Plant them on the east or north side of the house and provide adequate water.

Q: Is it all right to prune my palms now?

A: Thanks for pruning your palms at the right time. Remove only dead fronds, because green fronds are feeding the plant. This becomes even more important after frost damaged some green fronds last winter. Also, flowering stalks have emerged and you need to remove them. For those who pruned earlier, you need to remove the flowering stalks, because they can be dangerous when dropping.

Q: When do I fertilize my palms?

A: Do it now. There are many fertilizers developed specifically for palms. We are finding they need iron, manganese, zinc and magnesium, along with nitrogen, phosphorous and potassium. Apply fertilizer about one foot away around the trunk and slowly water it into the ground.

Q: What can I do to save my privet? The leaves are scorched with dry brittle stems and branches.

A: It's probably planted in the wrong place. It loves moisture and shady spots, so dry, sunny spots spell disaster for this old favorite.

You may still find life in the plant. Peel the bark back with your thumbnail; if it reveals brown, dry wood, move down until you reach a creamy-green and moist live wood. Remove dead branches just above the live side branches or dormant buds. Pruning encourages new growth, so provide extra water as the new growth appears.

For soils that have dried out, add a teaspoon of liquid dishwashing detergent to a gallon of water to break down what's known as surface tension of the soil. Surface tension repels water, causing it to shed off rather than absorbing it. One application of soapy solution is enough to soak up soil and keep it moist.

Q: It is June and I want to know why my Anna apples are falling off the tree?

A: They are ripening. They are early, as mine ripen in early July. Don't expect sweet apples, because it takes cooler temperatures to bring out the sweetness. Taste some. Remember, the first bite will be tart, but you will enjoy your second and third bites. Apples produced in our heat are not good keepers, but they make good applesauce and pies.

Q: Why do my grapes shrivel just before ripening?

A: When you combine wind with temperatures approaching 100, something must give and it's usually grapes withering. Keep the soil moist.

Q: What is causing spots on my grape leaves that turn into yellow blotches?

A: You probably have grape leafhoppers. Brush your hands through the grape leaves. If you hear something hitting the leaves, it's leafhoppers trying to get away; apparently they have poor eyesight. Your first reaction may be they are not doing much damage, but they are sucking sugars from leaves and your grapes end up tasting vinegarish. Go after them with repeated sprayings of insecticidal soap until they are brought under control.

Q: Our hybrid Bermuda lawn looks a mess after mowing, with patches of brown across the lawn. How can we control them?

A: If you are using a rotary mower, change to a reel-type mower to get a much closer cut, down to a half-inch above the ground. A rotary mower won't mow that low and thatch builds up. Then the rotary mower gouges into the thatch, causing brown spots and they become unsightly. Another possible cause of browning is an uneven lawn. If this is so, rake sand into the low spots and let it re-establish itself. If you still have gouging, filter more sand into the lower areas.

To find out if you have thatch buildup, remove a divot of soil from your lawn. Notice the area between the soil line and green grass. If that area is more than a half-inch thick, dethatch it. If you have never done this before, be warned because you are destroying your lawn. But continue with faith, because it will bounce back.

Q: Why do one or two gazanias suddenly die across the bed? I water every day.

A: You answered your question; frequent irrigations favor development of soil-borne diseases that infect plant crowns of these durable bloomers. The obvious solution is to cut back your irrigation turns, but water longer to dry out the soil surface. Also, thoroughly clean up all the debris when removing dead plants. The first symptom of disease is death of one or two plants in a patch. You'll find the outbreak worsens with repeated plantings. Apply the appropriate fungicides.

Q: My crape myrtle has no blossoms and sparse foliage. What is the problem?

A: Crape myrtle does not do well in parts of the landscape that are extremely hot and dry. In fact, don't use them in these situations. Avoid planting where they receive late afternoon sun or direct sun from the south, particularly near a wall. But if you must plant in full sun, surround them with low-growing shrubs or groundcovers to reduce heat and light bouncing back into the plant's canopy. The under-vegetation keeps the crape myrtle's roots moist and cool.

SPRINGS PRESERVE

Summer hours for the Springs Preserve are from 10 a.m. to 10 p.m., with the gardens and trail system closing at dusk. There is an admission charge to enter the galleries -- ORI-GEN Experience, Desert Living Center Sustainability Gallery, Nature Exchange and temporary exhibits -- but all other areas are open to the public at no charge, with a suggested donation of $6 for those going to the gardens and trails. For information on admission charges and more information on the Springs Preserve, visit www.springspreserve.org.

IRIS SALE

The Las Vegas Valley Iris Society is having its annual rhizome plant sale from 8 a.m. to 5 p.m. June 23 and from 9 a.m. to 3 p.m. June 24 at Plant World Nursery, 5301 W. Charleston Blvd. You will be able to get irises of every color and size, including tall bearded, medium, rebloomers, Louisiana, spurea and airlbred. If you were at the show in April, remember to bring your "wish list" of those you liked to make your choices. It's amazing how well irises do in the desert. If you already have an iris garden, come and get many new introductions.

Linn Mills writes a garden column each Thursday. You can reach him at lmills@reviewjournal.com or at the Gardens at the Springs Preserve, 822-8325.