Here are some gardening concerns I encountered this week.
Tomato bottoms rotting: This is a physiological disorder called blossom-end rot brought on by calcium deficiency. The black spot becomes depressed and inedible. Keep a constant supply of moisture available to dissolve calcium off the soil for your plants. Mulching goes a long way to stop the problem. I see it most often happening with the first set of fruit.
Vines to cover ugly fences: Here are some self-attaching vines to select from: cat's-claw vine, creeping fig and lilac vine. Virginia creeper, hacienda creeper, lady bank's rose, hall's honeysuckle, trumpet vine and grape will require trellises.
Shade summer vegetables: Shade will keep vegetables producing longer. Get the shade cloth from your nursery and cover tomatoes, sweet peppers, cucumbers and other sun-sensitive vegetables. Support the shade cloth with stakes or poles to keep the cloth off of plants. I use ridged PVC pipe.
Small tree for patio containers: Trees growing in containers eventually will become root bound. But until that happens, consider bay laurel, shiny xylosma, nandina, upright rosemary and citrus trees.
Plant amaryllis outside: It does great outdoors. Expect as many as two-dozen blooms that are even more striking than Christmastime blooms. A woman collects bulbs from friends after Christmas and plants them around her house. With different exposures, she has some blooming all summer.
Zoysia grass under trees: Zoysia grass does well under shady conditions where hybrid Bermuda fades out. You'll need to order sod, because it is not readily available; notify your nursery for date of delivery. Take the time to prepare the soil so you'll have a beautiful lawn. After laying sod, sprinkle the grass often and give it a shot of nitrogen for quicker green up.
Eight-year-old xylosma suddenly died: When plants rapidly die after eight to 10 years, I strongly suspect roots strangled it. This started back at the original nursery where plants were left in the small pots (liners) too long and eventually choke the plants to death. Dig it up and examine the root ball to confirm the problem.
Chitalpa tree bark splitting: Splitting bark is a common occurrence with chitalpa trees. Experts believe the lack of water causes the splitting. Pull back the split bark, and you'll find new growth forming to cover the wound. Immediately after splitting, trees set up defense mechanisms to wall off damaged areas to prevent pathogen entry. The tree will heal itself.
Brown blotchy leaves on chitalpa: This also is a familiar happening with this tree; however, it produces beautiful flowers similar to desert willow. You can do one of three things to correct it: Remove the tree, cut it down and restart it into a multiple-trunked tree or restart it, but remove a third of the branches each year thereafter similar to how you prune oleanders. They will get about waist high by fall. Your shrub will now develop a stunning bouquet of blooms.
I've noticed over the years that by restarting chitalpas, splitting and blotchy leaves go away. Apparently, it gives roots time to grow to support top growth.
Evergreen fruit trees: Citrus and loquat trees immediately come to mind. Citrus trees are marginal because of potential frost damage killing fruiting buds. Conquer this by protecting them from frosts. Loquat introduces a tropical effect into landscapes. It does best getting relief from the afternoon sun.
Cool plants with a shower: Cool down heat-stressed plants by giving them a midday shower. Use a watering-wand or hose-end sprayer, but remove the hot water in the hose to avoid scalding plants. Newly planted vegetables, flowers, small shrubs and lawns may need showering several times a day until they establish themselves.
Randomly plant cactuses: You often find cactuses in desert landscapes as single specimens rather than in groupings. However, cactuses are more aesthetically appealing when grouping them. In nature, it's common for one species of cactus to colonize an area with different ages and sizes in random patterns with different spacings between plants. Re-create such a colony by planting cactuses of one species in various sizes.
Herbs are easy to grow, wonderful to eat and virtually pest-free. These marvelous plants add fragrance to your garden and gusto to your meals with little effort. Explore all the delights herbs can bring and which herbs grow best in our desert climate at a program Saturday at 8:30 a.m. at the Springs Preserve, 333 S. Valley View Blvd. Call 822-7786 to reserve your seat.
Linn Mills writes a garden column each Sunday. You can reach him at firstname.lastname@example.org or call him at 822-7754.