Garden Care

The garden has slowed down some but everything is still growing. We have not had our usual noticeable cool down and we have temperatures in the low 80’s and lows about 70. The lawn maintenance companies are making extra money as they keep up the summer mowing schedule of cutting every 10 days to two weeks. We can have surprise freezes anytime from mid-December to mid-March. That event puts the brakes on all growing. Our weather is continuing warm so when the cold arrives everything will be in shock. Rainfall has been reasonable so far which also enhances everything growing.

The warm Gulf Stream is a major temperature modifier in South East Florida. I can remember in the early 1980’s when the temperature was 35 degrees at the Fort Lauderdale Airport which is one mile from the ocean. The University of Florida research center in Davie, Florida is 10 miles west of the ocean and the temperature there was 27degrees. Highway 27 is 20 miles west of the ocean and the temperature there was 19 degrees.

If a freeze is expected pull mulch back from the base of your plants. The warm soil will radiate warm soil temperatures up to the plants and help protect them. Water the day the freeze is expected which will help warm soil temperatures to reach the plants. Bring tender potted plants inside to avoid the cold. Cover tender outside plants with sheets or blankets to protect from freeze damage. Never use plastic as it will warm up quickly when the sun hits it.  Plant growth will turn to mush and put the plant in shock. The second night of the freeze is colder than the first night as the wind stops and the sky is clear. Warmer temperatures from the day radiate out to space. The third day is usually warm enough to pull coverings from the plants.

Clock Bush

Thunbergia erecta receives mixed reviews in most landscapes. I have seen it used in shady landscapes as a foundation planting and it does not perform well. Plants are very sparse in the shade and are not vigorous enough to be competitive with aggressive root systems. I noted this plant used as a low hedge under black olive trees and it was not happy. My plant receives full sun and is doing almost to well.

Plants with small foliage are preferred for hedging use as the foliage is not ripped by repeat pruning with electric hedge shears. Clock bush has showy, purple, trumpet shaped blooms, and small foliage. Hedges are normally pruned every 2-3 weeks and the flower buds are cut off before the plant can bloom. Your flowering plant is a green hedge without color. Plants like hibiscus, ixora, and others never bloom because of the constant pruning. One of the big complaints at condominiums is that there is no color in the landscape. Hedge plants should be selected that have small leaves and lack showy flowers.

The Ficus hedge met these requirements but had invasive roots and now whitefly concerns. I noted that plants with fuzzy or rough leaf undersides are not preferred by the spiral whitefly. Silver buttonwood is a possible choice but needs full sun and does not take extended pruning without some branch dieback. This plant is better as a small tree. One of the best choices may be Viburnum suspensum which has rough leaf undersides and takes sun or shade and does well as a hedge.  I have not seen this plant under whitefly conditions but suspect it may be a good choice.

Justicia spicigera ‘Sidicaro’

The common name ‘Orange Plume’ describes this shrub very well. It certainly has done more than well on my small property. Turf grass rules here with $50 fines if your wheels touch the grass. I find grass the most boring, high maintenance, expensive plant around. It is hard to get enthusiastic about it. Neat nicks in our retirement community do get exercise hand picking weeds out of the lawn. Getting back up after weeding is the challenge.

I planted ‘Orange Plume’ out by the street to block out traffic sounds and provide green and privacy. The shrub is flanked by areca palms that are dying from Ganaderma butt rot. I tied orchids into the palms and now one areca is dead. The other areca is about ½ gone.  Ganaderma has no cure so these palms are doomed. Weed whackers provide entry wounds for the Ganaderma to attack the trees.

‘Orange Plume’ is doing a great job in filling in for the dead and dying palms. The shrub must be 8 feet tall and 10 feet wide. I have to prune it back a bit on the street side but other wise leave it alone. The orange blooms are showy and certainly more interesting than the dead palm stems. Now, what to do about the orchids.

Clotilde Soupert Rose

This beautiful Polyantha rose was introduced in 1890 and is unusual for its wonderful old rose fragrance and large flowers. Most roses in the Polyantha class do not have fragrance. The blooms have a pronounced deep pink center in colder weather and the blooms increase in size. Flowers can be up to 3 inches across in the coolest part of the year. Mine are two inches across now and are mostly white with a hint of pink at the center. The coldest temperatures we have had so far have been in the upper 50’s. The blooms have over 100 petals which is very unusual for this class of roses. This rose is almost thorn free.

This rose requires special attention as far as planting location is concerned. You should choose a location with full sun, good air movement and drainage, and located away from concrete. The rose will be trouble free if you site the plant correctly. ‘Clotilde Soupert’ can get powdery mildew and black spot but seems immune to thrip and Sri Lankan weevil which attacked my ‘Knock Out’ rose which I just retired.

I have not had any problems with my ‘Clotilde Soupert’. Polyantha roses show occasional old stem dieback which is normal. The rose can eventually grow to 4-5 feet in height and spread. Plants are available at Jesse Durko’s Nursery in Davie, 954-792-2297

My ‘Mrs. B. R. Cant’ rose is starting to bloom again on what is left of the plant. This plant is struggling as the graft union is failing and the rose is gradually dying. The flowers are superb reaching 4 inches in diameter during the cooler winter months.  The foliage is healthy and has not been bothered by the Sri Lankan weevil and thrip that has knocked out the supposedly impervious ‘Knock Out’ rose. I hate to lose this beautiful but thorny rose. Grafted plants are often a problem as the graft union can fail as my rose is suffering from. Roses and gardenias are the most commonly grafted plants in Florida.

Plants are grafted to a root stock that is resistant to pests in our soil. Root knot nematodes are the most common root pest in Florida and most hybrid tea and other roses are grafted. This is an advantage for the old China antique roses which can be grown from cuttings and grow on their own roots.

Below are photos of my ‘Mrs. B. R. Cant’ rose showing clean foliage and blooms. I will try to take a photo of the bad graft union. I will also take a photo of the highly touted ‘Knock Out’ rose.

Radermachera elmerii

My Radermachera elmerii, is starting to shade the patio and eventually the air conditioning unit which should provide energy savings of up to 20% yearly. I love saving money on energy bills and this little tree should do it by next year. The tree is growing faster than I expected which is fine with me. I was thrilled with the 3-4 feet added to the overall height this growing season.

Nixon Smiley, author and garden columnist for the Miami Herald in the 1940’s loved this tree.  He reported it coming through unscathed after the 1945 hurricane that hit Miami with 145 mph winds. He liked the small size of the tree which is mature in the 20-25 foot range. He praised the beauty and neatness of the foliage which does not seem to drop at all. Flower drop is a problem with all blooming trees so they should be only used over lawn areas.

My experience with the tree has all been positive except for its tendency to produce sucker growth along the trunk and branches. This is easy to control by rubbing the tiny suckers off the trunk/branches before they get started.  This seems to be a characteristic of the Radermachera genus as my Radermachera ‘Kunming’, Dwarf Tree Jasmine does the same thing.

Blooms on Radermachera elmerii are pink, trumpet shaped, with a yellow throat. The flowers average 2 inches wide and carried on spikes above the leaves. I have not detected any fragrance from the blooms but have not tried at night when many plants become fragrant. The tree flowers over much of the year but takes a break during the coldest part of the year. This tree is a real beauty and deserves a good common name.

My Radermachera elmerii, is starting to shade the patio and eventually the air conditioning unit which should provide energy savings of up to 20% yearly. I love saving money on energy bills and this little tree should do it by next year. The tree is growing faster than I expected which is fine with me. I was thrilled with the 3-4 feet added to the overall height this growing season.

Nixon Smiley, author and garden columnist for the Miami Herald in the 1940’s loved this tree.  He reported it coming through unscathed after the 1945 hurricane that hit Miami with 145 mph winds. He liked the small size of the tree which is mature in the 20-25 foot range. He praised the beauty and neatness of the foliage which does not seem to drop at all. Flower drop is a problem with all blooming trees so they should be only used over lawn areas.

My experience with the tree has all been positive except for its tendency to produce sucker growth along the trunk and branches. This is easy to control by rubbing the tiny suckers off the trunk/branches before they get started.  This seems to be a characteristic of the Radermachera genus as my Radermachera ‘Kunming’, Dwarf Tree Jasmine does the same thing.

Blooms on Radermachera elmerii are pink, trumpet shaped, with a yellow throat. The flowers average 2 inches wide and carried on spikes above the leaves. I have not detected any fragrance from the blooms but have not tried at night when many plants become fragrant. The tree flowers over much of the year but takes a break during the coldest part of the year. This tree is a real beauty and deserves a good common name.

Wrong Plant, Wrong Place

South Florida suffers from an epidemic of wrong plant, wrong place. This has been going on for years and accounts for our butchered trees under utility wires with V or L shapes. Palms are the worst example as they cannot easily bend to avoid wires. Palms only have one growing point at the top of the tree and if this is pruned out the palm dies. One often sees singed palm fronds where the leaves touch power lines.

One of the problems is that there is not enough information available on how big plants grow. One old book I have says that black olives grow to 20-25 feet tall. I saw black olives in Puerto Rico with trunk diameters of 5 feet and heights of 90 feet. This is one of the problems with books. What is written is based on knowledge from that time. Time reveals many other factors that authors may not have been aware of like the staining the black olives cause and trees splitting because of poor branch structure despite strong wood.

Most people are guilty of these oversized problems. When I moved to Florida I fell in love with the rainbow gum which has spectacular patterned bark. I first saw the tree at the Subtropic Research Center in the South Miami area. The tree I saw was about 20 feet tall and 20 years old. I did not know about oolite rock that the tree was growing in. Planting holes are drilled into the rock and the tree is planted in the hole. The tree is pot bound in the rock which stunts the growth. I planted a 3 gallon tree in sugar sand near my house in 1983. The tree did not have restricted roots and grew rapidly. I donated it to Softscapes Nursery in 1992 just 2 weeks before Hurricane Andrew hit. The tree grew 9 feet a year and was 65 feet tall and had a 20 inch trunk diameter when it was moved. The root ball was 11x11 feet and 4 feet deep. This tree weighed 28,000 lbs. when it was moved. The tree was loaded on a big flatbed truck and was replanted at Softscapes.

It is important to check for underground and above ground utilities before you plant. Sewers, septic tanks, drain fields and underground wires are all affected by tree roots.

No-Work Roses

Roses have a reputation for being difficult under Florida growing conditions. New pests like the Sri-Lankan weevil and thrips are causing more difficulties. Many roses must be grafted on ‘Fortuniana’ root stock to avoid root knot nematodes which prevent the uptake of water and nutrients to the plants. The universally used ‘Doctor Huey’ root stock is not effective against the Florida nematodes.

Old roses offer resistance to many old and new pests. China roses do not need to be grafted and can be grown by cuttings. China rose favorites like pink, 7-8 foot ‘Old Blush’, red, 7-8 foot ‘Louis Phillippe’, white, 4-6 foot ‘Ducher’ multi-colored, 8-10 foot ‘Mutablis’, red, 3-4 foot ‘Martha Gonzales’light pink changing to dark pink, 4-6 foot ‘Archduke Charles’ are good choices.

Polyantha roses are smaller growing than most of the China roses. They can get some black spot but seem to resist most insect pests. Pink very double blooms change to white on fragrant, 4-6 foot ‘Clotilde Soupert’, light pink blooms on 4-5 foot, ‘The Fairy’, this rose has newer forms with red and dark pink blooms. Pink blooms on 3-4 foot, ‘Caldwell Pink’, coral pink flowers on 6 foot ‘La Marne’. All do well here.

Tea roses are one of the parents of hybrid teas but most are disease free. Most tea roes are in the 6-7 foot size range and must be grafted. They make good cut flowers and offer soft colors to enjoy. Double flowering ‘Duchesse de Brabant’ is very fragrant and shell pink, yellow changing to pink blooms on thorn-less ‘Mrs. Dudley Cross’, and 8-10 foot deep rose, very double ‘Mrs. B. R. Cant’.

These roses all require full sun, good drainage, and good air movement to do well.  They should be watered in the morning only to minimize any possibility of fungal diseases.

Spiral Whitefly

This insect pest is causing damage to many landscape plants including Tabebuias, Gumbo Limbo, Live Oak, Pongam, Mahogany, Calophyllum, Clusia, Kapok, Pigeon Plum, Noronhia, Black Olive and other plants with smooth leaf undersides.  Palms include: Coconut, Adonidia, Veitchia, Date Palms and others, Shrubs include: Barbados Cherry, Duranta ‘Gold Mound’, Oleander, Cocoplum, Copperleaf, Wax Myrtle, and Dwarf Clusia.  Many edible plants like Mango and Banana are also attacked by this whitefly.

Sooty mold stains cars, furniture, and everything below affected plants.  The adult whiteflies leave disturbed plants like flying clouds of white.  This pest is especially troublesome in parking lots.

The whitefly congregates on the leaf undersides and lays eggs in a spiral pattern.  A waxy substance covers the eggs making the whitefly hard to control.

Natural control is always best and a tiny non-stinging parasitic Encarsia wasp has been released that will control the spiral whitefly.  The predator populations are always slower to build up than the pest but historically the natural predator is the best long term solution.  Some cities are not spraying at all due to expense and killing off the predatory wasps.  Once can fertilize plants to encourage plant vigor which will also help.

Parking lots and other locations of major impact may wish to apply other solutions but the predatory insect populations can be affected.  One should apply a strong jet of water to the undersides of foliage and then follow up with applications of Neem Oil every 7-10 days until the problem disappears is one possible solution.  Bayer Advanced Tree & Shrub Protect and Feed used as a soil drench should last for 6-8 months but must be used away from water.  It is imperative to follow label directions exactly.  I would not use any other chemical treatment.  Hopefully the predator insect will win if not poisoned by overzealous spraying.  Visit http://miami-dade.ifas.ufl.edu/ and click onto the “gumbo limbo spiraling whitefly link to view photos of the spiraling whitefly.