Lush begonias, hardy garlic, pesky hornworms - includes related article - Sunset's Garden Guide

Sunset, August, 1994 by Jim McClausland, Lynn Ocone

Tuberous begonias are among the most colorful flowers you can grow in shade, producing big red, yellow, white, pink, or orange flowers over lush, large leaves. Now, while begonias are covered with a profusion of flowers, is the time to learn and note what you like.

Some kinds bear extremely large, upright flowers, while others are loaded with hanging flowers. Get the upright kind for planting in beds, and the hanging kind for containers.

Any plants you buy now will give you a good show for the rest of the summer if you apply quarter-strength fertilizer weekly. Alternate doses of a bloom fertilizer (lower in nitrogen, higher in phosphorus) with applications of a complete fertilizer. Mist plants several times a day (misting heads on timer-controlled drip-irrigation systems make this easy).

When the foliage begins to yellow in fall, reduce watering until all the leaves have died. Then pull them off, lift and clean the tubers, and dry them in filtered sun for three days before storing in a dark, frost-free place for winter.

Extra-hardy garlic: Order bulbs for fall planting

This fall, you can buy a new garlic bred for cold climates. German Extra-hardy Garlic is a stiff-necked variety, too tough to braid after harvest. Order bulbs now for planting in the garden in September.

At planting time, divide the bulbs into individual cloves and plant them scar-ends down in well-drained, fertilized soil. The garlic will spend the winter sending out roots, foliage will emerge in the spring, and full-size bulbs should be ready for harvest next July or August, depending on your climate.

Water planting beds and mulch them heavily. In spring, after danger of hard frost is past, pull the mulch back to give tops room to grow.

The bulbs are standard in size and potency. You can order from Johnny's Selected Seeds, 310 Foss Hill Rd., Albion, Maine 04910; (207) 437-4301. Cost is $5.25 for three heads (20 to 30 cloves), $9.95 for six heads (40 to 60 cloves).

Choosing a caretaker for your trees

A good arborist offers a wide range of services, including pest and disease control, pruning, bracing, and fertilizing. If the trees in your landscape show signs of stress or disease, an arborist can diagnose the problem and often help correct it. Since trees can be worth thousands of dollars in replacement costs (to say nothing of their sentimental value), it pays to shop for the right caretaker. Here are a few suggestions to help you find a competent arborist.

* Don't be swayed by door-to-door solicitation. A good reputation is the best indicator. Talk with neighbors and nurseries to get recommendations. If you have a city arborist, call for referrals.

* Check the person's work for yourself. If possible, visit the homes of former clients.

* Get at least three estimates. Talking with different candidates will give you a better understanding of the tasks at hand, the individuals' capabilities, and reasonable prices.

* Be wary of arborists who suggest topping trees; this practice is rarely called for and usually does more harm than good.

* Consider credentials. The International Society of Arboriculture (ISA) offers a voluntary certification program. A certified arborist must have at least three years' experience, pass a comprehensive examination, and participate in continuing education. Certification does not guarantee an outstanding arborist, but it does indicate a serious professional. To find a certified arborist in your area, call the ISA's Western chapter at (602) 955-5315.

* Select an arborist who is insured and offers proof of coverage for personal injury, property damage, and liability.

The big green pests of the West

With their voracious appetites, hornworms can wreak havoc on tomatoes, and sometimes peppers and eggplants, by consuming leaves and gnawing green fruit. If hornworms are feeding on your tomato plants, the foliage may be here today and gone tomorrow. While hornworms can be 4 or 5 inches long, they're hard to spot because their bright green coloring blends with the foliage. The black pellets they excrete do show up on leaves and around plants; if you see pellets or defoliated stems, look for hornworms feeding on the undersides of leaves.

The two types of hornworms are both the larvae of sphinx moths: the tomato hornworm has a black and green horn on its rear; the tobacco hornworm has a red horn.

Handpicking hornworms usually provides sufficient control. If you choose to spray, apply Bacillus thuringiensis (BT), a biological control that kills leaf-feeding caterpillars. BT is most effective on young hornworms, which stop feeding soon after ingesting the spray. Follow the label directions, and for maximum control, reapply every few days while the hornworms are active.

Nature has its own way of controlling hornworms. The hornworm pictured below has been parasitized by a natural enemy, the Braconid wasp. The wasps develop in the hornworm; when they emerge, they remain attached and spin tiny pale cocoons. The wasps eventually kill the worm.

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