The plants you see at the entrances to condominiums in the winter months are usually annuals such as begonias and impatiens. They make a big splash of color from October to April, but the heat and humidity of summer does them in. If you do not mind the yearly expense, annuals give the best color display of all. Perennials are not as showy as annuals, but last more than one year. Their life span is at least two to three years, and most last longer than that. Low growing perennials (1 to 3 feet) which like full sun include: lantana in yellow, purple, and other colors and bush daisy in yellow and orange. Peace lily in white and justicia in pink or white want shade. Pentas is taller growing (3 to 4 feet) and comes in pink, red, white and hot pink. 

Q. Help me save my pentas. They are two years old but are dying from the bottom. We did a xeriscape design with our plantings and really love the pentas. Can I start new plants from cuttings? 

A. I am very fond of pentas as a fairly tall growing flower that blooms every day of the year. It is a perennial and lasts for a good number of years. Nematodes can attack the roots in sandy soil and stunt growth so it is good to use about 50% peat moss mixed with the existing soil for planting. My pentas have lasted six years and are still doing well. They do not like much water and if they are in an area where water stands or is slow to drain, they will die. They do not like mulch up against the stems because the bark can't breathe. Pull the mulch at least 1 to 2 inches from all plantings. Pentas can be started from cuttings. You will get the best results between April and September. 

Q. I planted ruellia and after two months they diminished in size. What went wrong? 

A. The dwarf ruellia were eaten by snails; use snail bait or diatomaceous earth for control. 

Q. I have two daylily plants growing only a few feet apart. One blooms and the other has good leaves. They are planted at the same depth. How can I increase blooming? 

A. Daylilies need at least six hours of sun to bloom well. They like a well-drained location with no standing water. Fertilize with an acid gardenia/ixora fertilizer to encourage more bloom. Keep mulch away from the plant stems to avoid rot. Most daylilies bloom here in April/May, but there are some new repeat bloomers that can flower on and off until October. Evergreen daylilies do well here, but dormant and semi-dormant varieties do not receive enough of a cold rest period and do not do well. I would hesitate to order daylilies from mail order catalogues because most varieties they all are semi-dormant or dormant types. Palm Beach Daylily Gardens is a daylily grower who has plants suitable for south Florida. 
 

A. Try tough, colorful plants such as lantana, pentas, dwarf crown-of- thorns or ruellia. Space about 1 foot apart. If no water is available, wait until June before planting. Then nature will water for you. Add one quarter peat moss to the existing soil to improve its moisture retention. Old shredded leaves, grass clippings, etc., can also be mixed with the existing soil to improve it. 

Q. Can you recommend plants for a wet location on my center island? 

A. Many plants will do well in a damp area. If you want trees, I suggest red maple, sweet bay magnolia, wax myrtle, dahoon holly, red bay, bald cypress, and strawberry guava. Shrubs could include cocoplum, crinum lily, Fakahatchee grass, buttonbush, leather fern, elderberry and Florida privet. Low plants could include lizard's tail, and sword fern. 

Q. Can you recommend some plants for a perennial garden 4 by 18 feet that faces south? There is some filtered shade from palms. 

A. Many perennials last about two years and then die out, as most bloom every day and exhaust themselves. The new tall (3-4 feet) permanent ruellia with blue flowers would be good as a background plant. A midsize pink ruellia is also available. Some of the repeat blooming daylilies would be good additions. You might use dwarf Fakahatchee grass as an accent. Pentas is always good and attracts butterflies in tall varieties to 4 feet and dwarf types, about 18 inches. Their flowers are white, pink, red, purple and lavender. A good ground cover for the front of the bed could be purple fountain salvia. All these plants should last beyond two years. 

Q. I ordered rose mallow (Hibiscus moscheutos) and rose of Sharon (Hibiscus syriacus) from a catalogue. The rose mallow is blooming beautifully. Will the rose of Sharon amount to anything? 

A. Rose mallow is a native in northern Florida. I do not know if it will be a permanent plant here because we don't have cold periods and the plant needs some dormancy. I prefer to get plants from good local nurseries. Rose of Sharon will grow here, but is out of its best growing range. 

Q. Last year you recommended begonias as a substitute for impatiens as they were perennials. I purchased fibrous begonias which I find are annuals. Can you clarify this for me? 

A. Annual begonias have names such as wax, fibrous, semperflorens or bedding begonias which all mean the same thing. They are small mound-like plants used for borders, grow about 1 foot tall and come in red, pink and white. They usually last the entire winter dry season from October to May, can take sun or shade and do not have special excessive watering requirements like impatiens. Perennial begonias come in several classes and are permanent. The rhizomatous begonias have creeping roots, showy foliage and white to pink blooms. They flower mostly in winter and spring. The cane type begonias bloom all year on arching canes and can reach 4-6 feet tall. They are troubled by nematodes but are most enjoyable while you have them. Shrub type begonias also bloom most of the year in pink, red, and white. See the Begonia odorata `Alba' discussed under "Plant of the Month" for September.