July 8, 2004

Brown thumbs can find success with the right outdoor trees, plants

By Shari Kaplan
Staff Writer

Last month this column featured a discussion on how brown thumbs can gain enough confidence to find horticultural success. After reading some of the plant care hints and testing the waters with hard-to-kill houseplants like mother-in-law’s tongue, cast-iron plant and pothos, hopefully even the brownest thumbs are now going green.

This month we move from the indoor realm to the great outdoors. Fortunately, there are many easy-to-grow trees, shrubs and flowers.

Tree of Heaven
Tree of Heaven (Ailanthus altissima) is sometimes called a “weed” because it spreads by suckers, self-sows everywhere and has unfragrant flowers. However, it has many redeeming qualities, especially for people who lack the time, space or conditions for more finicky trees.

The title character of “A Tree Grows in Brooklyn” was, in fact, a Tree of Heaven that grew against all odds. Hardy, fast-growers with pinnately compound leaves and winged seedpods, these deciduous trees tolerate drought, heat, exposure, wind, pollution and poor soil.

Often seen along freeways, where saplings grow in thickets, they can ultimately reach 50 feet tall and wide. Even if you can’t grow anything else, you can grow Ailanthus!

Empress Tree
An opposite in terms of classiness is the Empress Tree (Paulownia tomentosa). Also called Royal Paulownia, this deciduous tree is named after Anna Paulowna, daughter of an 18th Century Russian czar. Although not drought-tolerant like Ailanthus, it’s a very fast growing shade tree, germinates easily, loves full sun, gets along in various soils and tolerates air pollution.

The large heart-shaped leaves are striking, and the purple spring blossoms are fragrant. Its main challenge is the fact that its flower buds form in autumn, so where winters are too cold, buds may freeze, and where winters are too mild, buds may fall off altogether. Fortunately, the Santa Clara Valley offers a happy medium.

Fern pine
One of the most versatile trees is the fern pine (Podocarpus gracilior). You can’t go wrong with this evergreen, because it’s equally at home as a hedge, shrub, espalier, container specimen or in-ground tree.

And no matter how it’s sheared, it will recover! Fruit is rare and leaf drop minimal, so there’s not much to clean up around fern pines. They also adapt well to many soil types and climates.

Olive
Another versatile tree is the humble olive (Olea europaea), which successfully grows in hot, dry climates as well as cool coastal areas. Whether soil is deep and rich or shallow and rocky, olives will take root.

They also spring back amazingly from pruning—you can even cut one to the ground, and it’ll return as a huge shrub. “Barren” varieties are available for people who don’t like messy fruit drop, but why not get the fruiting type and learn how to cure your own tasty olives?

Flowers
Let’s not forget flowers! California poppies (Eschscholzia californica) are very easy to grow, as evidenced along rocky, dry freeways. Although drought-tolerant, poppies bloom longer with summer irrigation. The only thing they really dislike is being transplanted, so always sow seeds with forethought.

Cheerful white, pink or purplish rockrose (Cistus genus) is even more drought-tolerant; it’s actually fairly tolerant of everything, including hot and cold temperatures, wind, poor soil and even salt spray.

Other attractive flowering plants with fairly simple—albeit different—needs include aloe, echium, gazania, geranium, hollyhock, Jupiter’s beard, lantana, mallow, nasturtium, natal plum, sweet alyssum and wisteria (a woody vine occasionally trained as a shrub or tree).

Many other vines are also beginner-friendly. Trumpet vines (Distictis genus) bloom profusely in bright red, orange or purple throughout the year in mild climates. All they ask for is well-drained soil and something to climb on.

Blue dawn flower (Ipomoea acuminata or I. indica) is an extremely vigorous climber that blooms almost year-round and is more than glad to blanket any fence, wall or trellis with its big purplish-blue blossoms.

This column is not, of course, meant to be an exhaustive list, but rather a way to get started on the right foot—or thumb, as the case may be.