The Sunnyvale Sun

Gardening

Veggie Helper: Marigolds are aromatic, reliable, fast-growing annuals. Flowers bloom in various shades of yellow, orange and brownish-red. Marigolds grow best in full sun with regular irrigation.

This is a tiny yellow flower producing juicy, red tomato

By Tony Tomeo

It is amazing that something as excellent as a bright red, juicy, ripe tomato can come from such a nondescript small yellow flower. It seems they should be produced by big, colorful rhododendron flowers, which conversely produce only small seed capsules. Perhaps tomato plants want to conserve resources from flower production for fruit production, and rhododendrons squander their resources on bloom, so have nothing left for fruit. Both techniques take considerable energy.

This is why tomato plants are more productive if their fruit is harvested as quickly as it ripens. If extra or unwanted fruit is left on the plants, it continues to draw resources that otherwise could be diverted into newly developing fruit. Prematurely harvested zucchini is better flavored and more succulent than mature fruit and, like promptly harvested tomatoes, is less of a burden on the plants that produce it. One tougher and less flavorful mature zucchini requires more resources than several small zucchini.

Flowering annuals are not exactly known for their fruit production, but that does not mean they do not produce any. The small seed capsules of rhododendron, rose hips and the various seed "pods" of some annuals are all forms of fruit that require a considerable expenditure of resources. Like harvesting developing zucchini, removal of developing fruit from flowering ornamentals conserves resources and promotes continued bloom.

The process known as dead-heading is the removal of fading blooms, which almost always includes the removal of the developing fruit structures of the plants that produce them. Many ornamental plants are so extensively hybridized they do not produce viable seed, so consequently do not produce fruit structures. However, some of these produce floral structures that linger as they deteriorate. For example, the broad, flat trusses of the floss silk flower, and the dense, vertical trusses of celosia, will turn brown and mushy if not dead-headed after bloom.

Dead-heading is, of course, impractical for some flowers. The very finely textured and small flowered annuals, such as lobelia and verbena, produce such small fruit structures, and in such profusion, that their removal is not practical. Sweet alyssum, coreopsis and portulaca are left because they also produce many small flowers, and also because they reseed directly back into the garden so well.

Other flowers that might perform better if dead-headed sometimes are not, or at least not completely. Nicotiana and marigold are often dead-headed, but some people like to leave a few fading flowers to provide seed for later. Strawflower and statice are often left after bloom because their flowers dry so nicely. Branching sunflowers are often left to make seed to feed birds, who might leave some to plant next year. Single sunflowers are usually left to make seed to feed people, even though the birds are not quite so gracious about sharing.

Although not intended to promote bloom, dead-heading weeds, particularly those that bloom only once, can effectively eliminate some of their seed before it disperses.

Flower of the Week: Marigold

With such perfectly clear shades of yellow and orange comparable to nasturtium, and flower profusion comparable to impatiens, marigold, Tagetes erecta and Tagetes patula (and their hybrids) continue to be among the most popular of warm season annuals. Like nasturtiums, some varieties of marigold bloom nearly white, pale yellow, red, maroon or nearly brown, and many of these are bi-colored. The 2-inch-wide or wider flowers can be single, very double or anything in between. Bloom begins with warm weather and continues until frost. Dead-heading promotes fuller bloom.

A few varieties can produce their own seed for next year if a few spent blooms are left to dry in autumn. The finely divided foliage is quite aromatic. Most types of marigold are less than 10 inches tall and wide. The larger varieties that can get taller than 2 feet may need to be staked, and can get broken by overhead watering. Planting these tall types with their root balls 2 inches or so below the soil should promote stability.

Horticulturist Tony Tomeo can be contacted at 408.358.2574 or at LGHORTICULTURE@aol.com.