These are some problems facing gardeners this summer.
■ Palms destroying walls: Palm roots create a lot of pressure on walls, footings, foundations and pools. If the roots find a crack, they’ll follow it to the water source. Palm roots do not expand in girth like regular tree roots, so they stay about the diameter of a pencil. However, lots of roots develop so they are able to push against structures, so plant farther away.
■ Golf ball-size Early Girl tomatoes: It’s caused by a lack of nitrogen. Tomatoes need more nitrogen than people realize.
■ Crisp brown grape leaves: It’s grape leafhoppers removing all the chlorophyll from the leaves. Stir vines and listen as they attempt to escape. Use neem or insecticidal soap to control them.
■ Flowering purple plums with green leaves: There are many flowering plums with green leaves. Sunset’s “Western Garden” book mentions several. Know what you are buying to get the purple plum varieties.
■ One side of Texas Ranger dying: The plant is getting water only on one side of the root ball, especially if it’s on a slope. Place a gallon can poked with holes above the plant and put an emitter in it to trap more water for the plant.
■ Rosemary dying: Rosemary plants cannot tolerate poorly drained soils and dies of root rot. Also exposing old interior wood when pruning will not regenerate new growth.
■ Orange bird of paradise losing leaves: It’s not getting enough water. This Caribbean plant takes heat but need lots of water to keep it blooming.
■ Top tier of poodle privet dies: Most likely sunburn and/or borer damage girdled the trunk. Sunburn expresses itself by bark darkening on the southwest side of the trunk and borers move in to decompose it. Using a pocketknife, peel back bark to examine between it and the hard wood; if you see sawdust packed in galleries, it’s borer damage.
Remove the top tier and restart the bush. Allow only one stem to grow upward from the lower tier and remove all others. Let it grow to the desired height and remove its growing point to redevelop a new poodle.
■ Golden euonymus suddenly dropping leaves: This is a strong indication of plants stressing for water. Check the rooted area to see if the root ball is dry and if the irrigation system is working. Deep-irrigate the rooted area and it will likely come back. Remove dead branches and you’ll feel better.
■ Blackberries failing: You must constantly rejuvenate blackberries by pruning to stimulate new fruiting wood, otherwise plants go downhill fast. The berries also need micronutrients to keep them producing high-quality berries.
Blackberries are perennials but canes must be biennial before producing berries. During the first summer of cane growth, nip it back to waist-high to cause branching. It’s from these branches berries come next year. After harvesting, remove these now old canes as others emerge to rejuvenate the plant.
■ Stubby transplanted carrots: When transplanting them, you broke off the taproots and they never redevelop. So, either eat the thinnings or compost them.
■ Four-year-old Kadota fig now producing: This is the age when Kadotas begin producing, not two years ago as most gardeners want. Figs are very durable trees for our climate.
■ Texas sage bushes blooming now: They are also called barometer plants; when the barometer drops, they bloom. Shearing them now inhibits their beauty, so prune after they bloom.
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Here are some other issues:
■ When to prune Mexican blue palm: Never remove thriving fronds. They are still producing food for the palm. Remove only dead and aging fronds.
Mexican blue palms are beautiful when blooming. Fragrant creamy-white flowers cover “garlands” arching out over the plant. The blue, waxy fronds also grab your attention as they arch out to form a wide-spreading crown.
■ How to germinate mesquite seeds: Plant seeds before October. Sandpaper the seed coats so water can penetrate the seeds, and soak them overnight. Plant the now swollen seeds a half-inch deep and keep moist until seedlings emerge in about two weeks.
■ How to develop a multitrunked Mexican bird of paradise:
1. Decide how many trunks you want.
2. Select the strongest trunks and remove the others.
3. Let those trunks grow this year.
4. In the spring. tip the trunks to cause forking.
5. Thin out branches as new growth appears.
Linn Mills writes a garden column each Sunday. You can reach him at firstname.lastname@example.org or call him at 702-526-1495.