DEAR A.J.: Gaura is one of my all-time favorite flowers. For years I tried to transplant them from the fields into my garden with zero success. Now, fortunately, they are available at nurseries and transplant easily.

I'm not sure if overwatering is the specific reason why the leaves have brown spots but it well could be. One reason gaura is such a great plant is that it requires so little water. Think about it. These flowers bloom in open fields all over Houston where they get no water whatsoever during our long blasting hot, drought-filled summers, except for our occasional rains.

Can you reset the sprinkler so that these are protected from so much water?

This is a major mistake so many gardeners make. They put in drought tolerant plants, plants hybridized or selected because they require very little water, and then set the sprinkler to water them too often. Of course the plants don't like it, they become weak and are more susceptible to insect and disease problems.

Your spots could be a fungal problem that a healthy plant would have been able to repel on its own but, because it's been weakened by overwatering, it can't. It's really hard for me to say for sure, but I can assure you gaura will have problems if it's overwatered.

Hope this helps.

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DEAR BRENDA: My dianthus is doing nothing...It is in the shade and really has never bloomed. I keep pinching the old stuff off of it, but it really does nothing. Also, my neighbor has a cactus called a century plant and it has shot up a huge, tall stalk with strange looking flowers. He researched it and found that particular plant gives off those stalks every 60 years or so, but he has had it for only about 5 years. BR

DEAR BR: First the dianthus.

1. They need sun.

2. It's late May. Even if moving it into sun makes it perk up, dianthus are like pansies, larkspur, snapdragons, etc., only a tad hardier. They strut their stuff usually from October through April, then go rather dormant.

Some folks manage to keep dianthus blooming all summer, but normally no, they do just what yours is doing. Cut it back, leave it alone. It'll come back in the fall when it cools down.

Re the Century plant, they are so called because it seems like a century between blooms, not because it really is. Sometimes they'll bloom every year for several years and then not bloom again for five years. It depends on weather combinations (assuming they are in an extremely well drained site). At the beach, they bloom almost every year, but they're growing in pure sand there. I suspect, since they are so genetically programmed to grow in areas of almost total drought, the more water they get, the less they bloom. But I'm just guessing.

Enjoy! You may not see another bloom for a while.

One more thing: Lots of plants are called century plants (because they take so long to bloom) — especially agaves and yuccas. Check out these websites and see which one you really have:

• http://www.naturesongs.com/vvplants/centuryplant.html 

• http://www.saguaro-juniper.com/i_and_i/agaves&yuccas/agaves&yuccas.html 

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DEAR BRENDA: My rose buds are turning brown before they even open, then when they open, they look dull with brown edges. Is this because of the sprinklers hitting them with water or what? My dwarf gardenias have not bloomed yet, but the leaves are turning yellow and falling off. I tried a little iron on them 2 weeks ago, but no improvement. Any ideas? V.E.

DEAR V.E.: Re roses, sounds like you have thrips. Pop open one of the buds and see if there are some little bugs inside.

www.houstonrose.org is the official Houston Rose Society website. Click on FAQs.

This is what they say about thrips:

Thrips are tiny insects that suck on rose petals, turning the petals brown. You don't see this discoloration on red or pink roses, but it shows up clearly on white blooms. You have two choices: live with the discoloration or spray a mild insecticide directly into the bloom just before it opens. The thrips are not on the whole plant, so don't spray anywhere except into the center of the soon-to-open bloom. Each bloom gets one spritz of insecticide. If the bloom takes a while to open, you may have to spray a spritz each day to make sure the thrips are gone. Organic gardeners use garlic spray instead of insecticide.

It shouldn't hurt the roses to have the sprinkler hit them, but overwatering them will cause them to be weak and more susceptible to roses. Ordinarily I tell folks that it's pointless to keep treating bug problem without finding out why the plant is so weak it can't repel bugs on its own. All plants have a built-in resistance to insects and disease.

Grafted roses (the only ones that have thrip problems here) are another story. They (and gardenias -- to answer your second questions) really don't like our high humidity, heavy spring and fall rains, our long summer droughts, or our heavy clay, slightly alkaline soil.

Both grafted roses and gardenias like even moisture year-round, reasonably cold winters (at least colder than ours) and well drained, sandy, slightly acidic soil. You can compensate for all these drawbacks, and in some areas of Houston they do quite well. Some grafted roses are extremely hardy here. Others are always problem-plagued.

But it's been my experience with gardenias ( sorry to say) that almost always they do really well for a few years, and then become so weakened by our alien climate that they start having lots of problems.

Temporary infestations may come and go, but if they're a major problem and you're doing everything right, then get rid of the plant. Get a plant that doesn't have unacceptable levels of insect and disease problems in your area.

If you're addicted to the gardenia scent (as I definitely am), and your gardenias finally succumb, try to find a cape jasmine. When you see large "gardenia" shrubs these are cape jasmines, the plant from which the smaller shrub "gardenias" on the market were hybridized.

In the meantime, is the gardenia REALLY well drained? Remember our gumbo clay soil holds moisture and when we have heavy rains, are the roots sitting in wet soil for a long time? These prefer sandy soil where the rain just sort of kisses the roots as it passes by.

I'm assuming you live around Houston. If you live in an area with sandy soil, then you can forget this part.

If not, try lifting your gardenia out, raising the bed level and replanting it. Their roots like to spread out sideways along the upper soil levels. If the roots are too deep, the plant has problems. Work some peat moss or finely ground bark mulch into the soil. This will help make it more acidic. Then mulch really well with pine needles, oak leaves and/or bark mulch, all of which will help make it more acidic. Don't overwater and don't plant anything else too close by.

Prune it back no more than 1/3 and hope for the best.

Grafted roses also do better if in a bed at least a foot above ground level,. Have you thought of antique roses? These are hardy shrubs you can put in and forget.

EMAIL GARDENING QUESTIONS TO BRENDA AT: brenda@guidrynews.com

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GREATER HOUSTON/GALVESTON/BEAUMONT GARDENING CALENDAR

(If your group has a May event that is not listed, it's because it was not sent to me in time. Send gardening event notices to Brenda at brenda@guidrynews.com. Gardening event notices must be submitted by the 20th of the preceding month (eg. July events must be submitted by June 20. Events submitted to this column may also appear in the Houston Chronicle Garden Calendar if space permits. These are pretty much printed as submitted and are in Houston unless otherwise specified.)

Friday June 3: Registration deadline for the Master Gardener Class, June 7-July 7, 8:30 a.m.-3 p.m. Tuesdays-Thursdays, Harris County Extension office, 3033 Bear Creek Park; www.hcmgap2.tamu.edu; $150. Register at 281- 991-8437. 

Saturday, June 4: 7th annual Tomato and Vegetable Contest June 4 at all three Cornelius Nurseries, 2233 South Voss Road, 713-782-8640; 1755 FM 1960 West, 281-444-1210, and 1200 N. Dairy Ashford Road, 281-493-0550. For entry details, log onto www.corneliusnurseries.com. 

Saturday, June 4, "Photographing Plants & Wildlife in the Garden" by Kathy Adam Clark, 10am, Buchanan's Native Plants, 611 E 11th, 713-861-5702, www.buchanansplants.com,  FREE

Saturday, June 4: "Hot Weather Plants" Aimee Perakes, experienced nursery professional, 10 a.m., Teas Nursery, 4400 Bellaire, 713-664-4400, www.teasnursery.com; free.

Saturday-Sunday (June 4-5): Peckerwood Garden Open Days, 1-5 p.m., 20571 FM 359 in Hempstead, 979-826-3232, www.peckerwoodgarden.com; $5. Open Days are an opportunity for the public to visit Peckerwood Garden for self-guided tours between 1 p.m. and 5 p.m. Parking is at Yucca Do Nursery. Please contact us or visit our web site for further information.

Saturday and Sunday June 4-5, 2005: Water Garden and Pond Tour; 10:00 AM to 5:00 PM, self guided tour of 34 residences in the Houston Area; Lone Star Koi Club and Houston Pond Society event; email _dcook1830@aol.com (mailto:dcook1830@aol.com) or call 713-688-8875; www.lonestarkoi.com or www.houstonpondsociety.org. 

Saturday-Sunday, June 4-5: Bromeliad Show and Sale, show2-6 p.m. Saturday, sale: 9 a.m.-6 p.m. Saturday, both: 11 a.m.-4 p.m. Sunday, Tyrrell Park Garden Center, 6088 Babe Zaharias Drive in Beaumont; free. Golden Triangle Bromeliad Society event, 409-886-5721 or 713-771-7585.

Sunday, June 5: “Growing Blackberries and Vegetables” by J. D. McMaster, 1-4 p.m., Blackberries of Houston, 19531 Cypress Church Road in Cypress, 28l-373-5357 or www.blackberrriesofhouston.com; free. Blackberries and gardening by two seniors citizens, Frankie and J.D. McMaster in Cypress,Texas, Free tour during May or June by appointment..The McMasters were owners of McMasters Rice Hull Compost for 25 years in Houston..Click our web site at www.blackberriesofhouston.com or 28l-373-5357

Sunday, June 5, "Mounting Begonias” with Tom Keepin, Houston Garden Center, 1500 Herman Drive, free, American Begonia Society event, 713-686-8539

Monday, June 6: Teas Kids' Garden Club program begins, 9:30-11 a.m. Mondays-Wednesdays through June 22, Teas Nursery, 4400 Bellaire, 713-664-4400, www.teasnursery.com; $5 per class.

Tuesday, June 7: "Houston Landscapes" by Kathy Huber, Chronicle Garden Editor, 12 noon. Harris County Extension office, 3033 Bear Creek Drive. HCMG sponsored event. Open to public. 281-855-5600, http://hcmga.tamu.edu 

Thursday, June 9, 2005:"Landscape Planning and Renovation," by Fort Bend Master Gardeners, 7:00 p.m., Bud O'Shieles Community Center, 1330 Band Rd in Rosenberg; free. Green Thumb Seminar, (281) 342-3034; or http://www.co.fort-bend.tx.us OR www.fbmg.com. 

Friday-Sunday, June 10-12: Bromeliad Show and Sale, sale: noon-6 p.m. June 10, 9 a.m.-5 p.m. June 11, 11 a.m.-4 p.m. June 12; show: 1-5 p.m. June 11, 11 a.m.-4 p.m. June 12; Mercer Arboretum & Botanic Gardens, 22306 Aldine-Westfield, 281-443-8731; free. Bromeliad Society event, 713-858-3047

Saturday, June 11: Native Plant Society of Texas Attracting Hummingbirds – Native Ornamentals 10:00 a.m. to 2:00 p.m. Teas Nursery, 4400 Bellaire,713-664-4400, www.teasnursery.com; free.

Saturday, June 11: Plumeria Sale, 9 a.m.-3 p.m., Bay Area Community Center, 5002 Nasa Road 1 in Seabrook' free. Plumeria Society of America event, 713-946-9175 or www.theplumeriasociety.org 

Sunday, June 12: Hibiscus Show and Sale, 1-4 p.m., Bellaire Community Center, 7008 S. Rice Avenue in Bellaire; free. New members get two free plants. Many hybrid varieties available for sale at reasonable prices.

Monday, June 13th: Hardy Hybiscus by Georgia Bost of Village Botanica, 7pm, Good Shepherd Episcopal Church, 2929 Woodland Hills in Kingwood; free. Lake Houston Gardeners event, 832-368-9870.

Monday June 13: “How to Start a Community or School Garden” by Gary Edmondson, 4:00-6:30 p.m., Urban Harvest, 1900 Kane; free. Register at 713-880-5540. Information at www.urbanharvest.org. Learn the basic ingredients for a successful community or school garden, including planning, budget, materials and garden design. Gary Edmondson is the School & Youth Gardens Coordinator for Urban Harvest.

Wednesday June 15: “Sell What You Grow at a Green Market” by Gita Van Woerden, 4:00-6:00 p.m., Urban Harvest, 1900 Kane; $30. Register at 713-880-5540. Information at www.urbanharvest.org. Techniques and strategies including selecting vegetables for market, transportation, packaging, pricing, displays, set-up, regulations and certifications. Gita Van Woerden is a market farmer at Animal Farm Permaculture Center.

Thursday, June 16. "Facts and Folklore about Texas Native Plants." by Karen Breneman. 7PM, Houston Arboretum and Nature Center, 4501 Woodway. Free. Native Plant Society event. (713)681-3665 or www.npsot.org. 

Monday June 20: “How to Start a Community or School Garden” by Dr. Bob Randall, 1:00-3:45 p.m., Urban Harvest, 1900 Kane; free. Register at 713-880-5540. Information at www.urbanharvest.org. Learn the basic ingredients for a successful community or school garden, including planning, coordination, budget, materials and garden design. Dr. Bob Randall, the director of Urban Harvest, has advised over 150 community gardens over the last 15 years.

Thursday, June 23, 2005: "EarthKind Roses," by Carol Cammack Brouwer, Horticulture Agent with Harris County, 7:15, Bud O'Shieles Community Center, 1330 Band Road in Rosenberg, free. Fort Bend Master Gardener Program, 281.341.7068 or www.co.fort-bend.tx.us or www.fbmg.com.

Saturday-Sunday, June 25-26: Tropical Treasures Plants Sale and Seminar, “Exotic World of Gingers” by Beth Galiano, 2 p.m. June 25, “Mounting Ferns” by Michael Lowery, 2 p.m. June 26; sale 10 a.m.-4 p.m. both days, Nessler Civic Center, 2010 5th Avenue North in Texas City; 713-864-9717; free.

Saturday, July 2, "Gingers-Year Round Blooms" by Linda Fields, 10 am, Buchanan's Native Plants, 611 E 11th, 713-861-5702, www.buchanansplants.com; FREE

July 19: "Irrigation and French Drains" by Mark Dieter, 6:30 pm., Harris County Extension office, 3033 Bear Creek Dr; Free Master Gardener event. Call 281-855-5600; access http://hcmga.ramu.ed

Sunday, July 24:Hibiscus Show and Sale, 1-4 p.m., Bellaire Community Center, 7008 S. Rice Avenue in Bellaire; free. Hibiscus Society event, 281-756-0965 or www.lonestarahs.org.  New members get two free plants. Many hybrid varieties available for sale at reasonable prices.

Friday (Aug. 12): Registration deadline for the Saturday August 13 from 8:30am to 3pm; Basics of Residential Horticulture Part 2; Continuing the introduction to the science of gardening with seasona appropriate information. This includes composting, lawn dieseases and care, Bulbs, Fall Vegetable gardening, and recommended plants for the Houston area, tree care and pruning. Lunch included. Bear Creek Extension at 3033 Bear Creek Dr. $50.00

August 16: "A Taste of the Tropics: Flowers, Form and Fragrance" by Linda Gay, Director of Mercer Arboretum at 6:30 pm., Harris County Extension office, 3033 Bear Creek Dr; Master Gardener event. Call 281-855-5600. Access http://hcmga.tamu/edu

August 25: Harris County Master Gardener Fall Class, Thurs. for 12 weeks. 9 am-3-pm. Cost will be $150, call 281-855-5600 for application. Harris County Extension office, 3033 Bear Creek Dr. Access http://hcmga.tamu.edu. Reservation deadline is August 16.

Saturday-Sunday (October 1-2): Peckerwood Garden Open Days, 1-5 p.m., 20571 FM 359 in Hempstead, 979-826-3232, www.peckerwoodgarden.com; $5. Open Days are an opportunity for the public to visit Peckerwood Garden for self-guided tours between 1 p.m. and 5 p.m. Parking is at Yucca Do Nursery. Please contact us or visit our web site for further information.

OCT. 6-7-8, 2005 63rd Bulb and Plant Mart will be October 6, 7, and 8, 2005 at Westminster United Methodist Church 5801 Bering at San Felipe.

Saturday-Sunday (October 15-16): Peckerwood Garden Open Days, 1-5 p.m., 20571 FM 359 in Hempstead, 979-826-3232, www.peckerwoodgarden.com; $5. Open Days are an opportunity for the public to visit Peckerwood Garden for self-guided tours between 1 p.m. and 5 p.m. Parking is at Yucca Do Nursery. Please contact us or visit our web site for further information.

Nov. 6: Holiday Decorations for Mantel and Wreaths presented by Hollie Fairchild, 9:00 a.m. to 12:00 noon, Burgess Recreation Center, 4200 Kalwick in Deer Park, Cost $25.00 at the door. Deer Park Petal Pushers Garden Club event, 281-542-9731.

Friday, Nov. 18, and Saturday Nov. 19: 9am to 11:30 and 1pm to 3:30pm; Floral Design for the Holidays; Class instruction and hands-on assistance. Flowers and containers provided for Thanksgiving arrangement. Dr. Carol Brouwer and Michael T. Morrison will teach these two sessions. One in the morning and then another session in the afternoon. Refreshments. Bear Creek Extension Auditorium $50.00. 281-855-5600.

Friday, Dec. 9: Registration deadline for the Saturday December 10 9am-11:30, and 1:00pm to 3:30pm Either morning or afternoon session for hands-on training on floral designs for the holiday season. Flowers and containers provided for Christmas. Refreshments served. Michael T. Morrison and Dr. Carol Brouwer will teach the sessions. Bear Creek Extension Auditorium. $50.00. 281-855-5600

April 4, 2006: A Garden Club of America Small Flower Show. Presented by the 18 Clubs of The GArden Club of America Zone IX (Arkansas, Louisiana, Mississippi, Tennessee, & Texas), The Omni Hotel, Four Riverway in Houston. 713-871-8181

IF YOU ENJOY BRENDA'S COLUMNS, YOU'LL LOVE HER GARDENING BOOKS — available online at www.urbanharvest.com. 

FROM THE LAZY GARDENER •

• “The Lazy Gardener's Guide” — revised and updated! First published 10 years ago, The Guide is described by Brenda as “a gardening book in calendar format … so you don't have to think!” Based on her humorous-yet-informative Houston Chronicle calendar, The Guide details what gardeners should be doing in the garden each month, provides garden designs (using the hardiest plants for our climate) for butterflies, hummingbirds, sun, shade and a variety of other typical suburban situations. Filled with funny and touching anecdotes from decades of covering gardening in the Greater Houston/Galveston area. As the daughter of a BOI, many of these involve Galveston sites and people!

• GARDENING WITH DOGS. Co-authored with Frances Burke Goodman, this little booklet offers tips, landscape plans, good plants for dog-challenged areas and lots of fun insights into why dogs do what they do (and how you might just unknowingly be encouraging “bad” behaviors!)

Look for all these River Bend Company books at your neighborhood nursery this fall or online at www.urbanharvest.com.  For a list of potential retail sources, to order by email or to receive an order form, contact River Bend Company at 713-621-3468 or email: RiverBendBook@aol.com.