Tips to keep the bloom on your roses

Our cool spring temperatures have been producing beautiful roses. Everywhere I turn, I see roses in all their glory -- covering fences, climbing trellises and filling in landscapes.

The Las Vegas Valley Rose Society invites you to its annual rose show from 1 to 4 p.m. Saturday at the West Charleston Library, 6301 W. Charleston Blvd. To enter your roses in the judging competition, bring them to the library before 10 that morning.

The theme of this year's show will be "Have Roses Will Travel." With the closing of the Garden Center, the society had to find a new location for its meetings. They are held at
the NV Energy complex at
6:30 p.m. on the second Sunday of each month. For more information about entering the show or joining the society, call 702-646-6048.

Here are some concerns you might encounter with roses:

■ Sticky leaves: This is a sign of aphids. They are hard to wash off, so spray them with insecticidal soap or neem early in the morning.

■ Stained blooms: Thrips cause this damage. These tiny critters stain newly opened flower petal edges, and it's too late to stop them at this point. Spray only the unopened buds with a systemic insecticide; spraying everything kills beneficial insects that consume the thrips.

■ Spiderwebbing lower leaves: Watch the lower leaves for webbing as the temperatures heat up. It's a sign of spider mites feeding on the leaves. To identify these critters, shake webbing leaves over white paper and expose the paper to light. The moving specks signal an infestation of mites. Repeatedly wash the bushes with water and the mites will leave.

■ Leaf pieces missing: It's leafcutter bees taking pieces to build their overwintering nests. They were brought here to pollinate alfalfa and stayed. Their leaf sculpting won't harm your bushes.

■ Powdery mildew: The powdery stuff gets its start on moist leaves. Keep them dry by watering early in the morning so the mildew can't get started or use neem.

■ Leaf scorch: Salt burn appears along the edges of leaves. Give your bushes periodic deep and slow watering to leach away the salts.

Overfertilizing can also cause scorching. Follow instructions on fertilizer bags for the precise amount to apply.

■ Small leaves: Expect to see this as the heat sets in; it means the roses are growing too fast. There's no solution except to shade the bushes.

■ Yellow leaves with green veins: This is a sign of iron deficiency. Our alkaline soil causes this and weakens the plants. Apply iron chelates such as Kerex. It remains available to plants in alkaline soils. To make the application easier, put a tablespoon of Kerex into a five-gallon bucket of water and place a gallon of it on each rose.

It's also a sign of overwatering, so water longer but less often.

■ Create bigger roses: When buds on hybrid tea roses appear, save the lead bud and remove the side buds for larger roses. Remove them early or you'll get smaller roses. Do the opposite with floribundas; remove the center bud so the side buds can size up for larger bouquets.

■ Summer fertilizer schedule: Roses are big feeders. Give them a balanced rose food monthly at full strength now and in May. During the summer, cut it back to half-strength. Before applying and after each feeding, give plants a good soaking.

■ Miniature and container roses: These roses require less fertilizer but need it more often because of frequent waterings. Water after each feeding to prevent burning.

■ Removing over-the-hill flowers: With one hand take hold of a spent flower, and with the other hand follow down the stem to where it's the thickness of a pencil. Make the cut just above a leaf (five leaflets) to remove the spent rose. A new rose comes from this site, giving it a strong base to cope with winds.

■ Mulch: It is the real secret to success. Use shredded red cedar. Because of the cedar's smell, it seems to deter insects and funguses.

Under your roses, place two inches of mulch. It provides microorganisms to improve your soil and helps to conserve water. Mulch seems to tie the rose garden together.

■ Watering: You can get by on three-day-a-week waterings by mulching. If plants show signs of stress, water longer with each setting. Water long enough so that it soaks beyond the root zone each time to flush out the salts.

Linn Mills' garden column appears on Sundays. He can be reached at linn.mills@ springspreserve.org or (702) 822-7754.