Dahlias remain so out of fashion that there is never a wide selection at nurseries--even though there is probably more variety among dahlias than among any other type of flower. There is a lavender, daisy-flowered dahlia (D. imperialis) that grows from permanent roots to become a 20-foot annual tree. At the other extreme, there are dahlias only a foot high that have flowers nearly as big. Some large dahlias, such as Conquistador, have double red-and-yellow-striped flowers that seem to say: "Look at me. Am I not grand?" Others are more modest, such as Little Lamb, a small, dainty, white, cactus-flowered variety that is used in bridal bouquets. It can be eye-opening to go to a summer dahlia show and see what's available. For more information, contact a dahlia society in your area. You can find one through the South Coast Botanic Garden in Palos Verdes. Many catalogues are offered by dahlia growers; if you want one with color illustrations, send $2 (refunded when a purchase is made) to Swan Island Dahlias, P.O. Box 800 HD, Canby, Ore. 97013.
Poinsettias that were used in pots for Christmas can go into the ground as soon as the danger of frost is over. When selecting a site, bear in mind that those cute little potted plants can easily grow to a height of 10 feet or more. Potted azaleas often need more attention. Their pots tend to be too small and they probably have had rough treatment. New pots should be at least an inch wider on each side. Rough up the roots a bit so they will grow into the new mixture. Use an azalea or camellia mix and keep the soil on the acid side. Kalenchoes need protection from the cold and will sunburn--after having been indoors--if they're given too much sun at once.
The rainy season is drawing to a close, so make sure that plants don't dry out. Pots and bedding plants are the ones that need water most frequently. Don't forget, however, that Santa Ana winds can dry out just about everything.
Citrus trees should be fertilized as soon as the danger of frost has passed. That's the time of their greatest growth. Fertilizing them again at the time of bloom will help them hold their fruit. It is best to use a commercial citrus fertilizer, since many trace elements such as manganese, zinc and iron are required by citrus. The same fertilizer is good for gardenias, which should also be fertilized at this time.