All-America award-winning vegetables and flowers usually are among the best for gardens. They have been grown in trial gardens located in every climatic area of America, even in Mexico and Canada, and judged by experts.

Among famous all-America vegetable varieties still popular are Salad Bowl lettuce, Bell Boy pepper, Emerald Cross cabbage, Cherry Belle radish, America spinach, Spring Giant tomato, New Hampshire Midget tomato, Tokyo Cross turnip, Ruby Queen beet and Jade Cross brussels sprouts.

Among the vegetables to win awards in the first year of trials 40 years ago were Imperator carrot and Honey Rock melon, varieties that gardeners still grow today.

Many of the award winners have been milestones in breeding achievement. In 1962, for instance, Bravo dianthus won a silver medal. It was the first scarlet-red in this class and represented among annuals the same degree of breeding achievement as the black tulip among bulbs.

Sakata, the Japanese breeder, found this once-in-a-million mutation (Bravo) growing by the roadside. He nurtured it for four years and boosted it from obscurity to overnight fame by entering it in All-American competition.

Many new flowers are like new fashions, according to specialists. They enjoy a short, sensational period of popularity, then tall off to be replaced by something more sensational and novel.

Those that hit the top of the popularity polls and stay there are few and far between. Most of the America winners have been exceptions.

Thumbelina zinnia received a gold medal award in 1963 and outsold every other flower variety that year. Today, 13 years later, it still outsells many other flowers.

It was a triumph of modern plant breeding, grows just 8 inches high, and is covered with thimble-size blooms in a mixture of colors from white and yellow to red and purple.

In 1949 a plant-finding expedition to Turkey sponsored by USDA returned with specimens of an unusual new variety of basil. After several generations of selection, the University of Connecticut developed a true breeding line called Dark Opal.

Although edible as an herb, just like normal basil, scientists decided it had value as an ornamental plant, and in 1960 it won an All-America award. It has proved to be valuable as a border or background to low-growing plants.

Foxy foxglove was the first annual foxglove. All other foxgloves are biennials, requiring two years to flower from seed.

Firecracker zinnia was the first giant hybrid flowered zinnia, and Carefree geraniums were the first geranium hybrids to grow true to color from seed.

Sunset cosmos was the first reddish-orange cosmos, and a magnificent display flower for the garden, while Rosie O'Day alyssum, a beautiful deep-rose color, was the first of its kind in annual alyssum.

Marigolds represent the longest list of award winners and Burpee leads the field with 17 awards in this class alone. Most are still in good demand.

Among snapdragons, Goldsmith has made the best improvements recently, especially with his new Butterfly series with flared, wide-open throats.

Table King bush acorn squash won a silver medal in 1974 for the extra large size of its dark, glossy green fruits and the compact, bushy habit of the plants.

Developed by the University of Connecticut, Table King brings acorn squash to the small family-size garden. It is earlier yielding, the flavor is excellent and the seed cavity is small compared to other bush varieties.

Goldcrop waxbean also was a 1974 All-America winner. It is disease resistant, there is less blossom drop during hot weather than most snap bean varieties, and produces slender, crisp yellow pools that snap when bent.

Yellow Baby F-1 Hybrid watermelon, Premium Crop F-1 Hybrid broccoli and Snow Crown F-1 Hybrid cauliflower were 1975 All-America winners.

Premium Crop won a silver medal. The big, solid central heads are ready to eat in less than two months after setting plants in the garden and its hybrid vigor and disease resistance assure crops under adverse conditions.

Snow Crown also received a silver medal. It forms heads a week earlier than standards varieties, produces solid 2-pound heads ready for salads, steaming or freezing. One head will serve a family of four.

There were no All-America vegetable awards in 1976.