Ask Wendy
Weekly Home Horticulture Column
Winter 2004
- Artichokes
- Azalea
- Cacti
- Calamondin Tree
- Carpenter Bees
- Chinaberry Tree
- Epsom Salts
- Gloriosa Lily
- Herbs
- Lawn - Cold Damage
- Lawn - Leaves
- Lawn - Weed and Feed
- Pampas Grass
- Plum Tree
- Redbud Tree
- Spanish Moss
March 2004
We would like to plant Artichokes here in Northern Florida. Do you have any literature about this wonderful vegetable? (Alachua)
The globe artichoke is also known as the French artichoke or green artichoke. These are not normally grown in Florida. Almost all of the nation's globe artichokes are grown in a narrow coastal area of California because of the favorable climate there. They are considered a perennial that is frost sensitive. These thistle-like plants are grown for their large edible buds.
Artichokes thrive in areas that have cool foggy summers. Cool and foggy is not how we would describe the summers in North Florida! In the warm weather the buds open very quickly, destroying the tenderness of the edible parts of this thistly like bud.
Gardeners who would really like to try to grow artichokes should try a variety called 'Green Globe'. It should be grown from seeds or root shoots from the last year's plants. Early in the spring plant the root parts around 6-8 inches deep, 6 feet apart in rows 8 feet wide. Fertilize, irrigate and cultivate just as you would other vegetables in the garden.
I want to know what kind of plum trees that produces fruit, will live in our zone. I have seen a couple around town that look great and produce fruit, but no one knows the name of it. I saw one at a local nursery, (Santa Rosa) but was afraid to buy it. (Gainesville)
The plums that do best here in Alachua County are the ones that were specifically bred and selected to be productive in our climate. We get around 500 chill hours (temperatures below 45 degrees) per year. The plums trees that produce fruit for us need around that chilling requirement to flower, and make plums. The Santa Rosa needs more chilling than we get here in North Central Florida and performs better up in the panhandle. The varieties that we recommend are the Gulf Gold, Gulf Ruby, Gulf Beauty, and Gulf Blaze. These plums are delicious when fresh picked off the tree. In my opinion they rival any plum that is shipped in from California or Chile.
I know that I have carpenter bees, and I have had my pest control company out to treat for them. However, we treated the wrong area (although we were close). I would like to know how to prevent them from nesting in my home. I live in a condo, and I have wood siding. Would it be possible to treat them with a sealant to prevent the bees from nesting? (Gainesville)
I know that I have carpenter bees, and I have had my pest control company out to treat for them. However, we treated the wrong area (although we were close). I would like to know how to prevent them from nesting in my home. I live in a condo, and I have wood siding. Would it be possible to treat them with a sealant to prevent the bees from nesting? (Gainesville)
Carpenter bees prefer to attack wood which is bare, weathered and unpainted. So the best way to deter the bees is to paint all exposed wood surfaces, especially those which have a history of being attacked. Wood stains and preservatives are less reliable than painting, but will provide some degree of repellency versus bare wood. Preventive sprays applied to wood surfaces are effective only for a short period, meaning that you would have to 
repeat the application about every 2-3 weeks. However, once nesting activity has begun damage may be substantially reduced by treating the entrance holes with an insecticidal spray or dust. Products containing Sevin, cyfluthrin or resmethrin are recommended. Aerosol forms will be easier for you to apply.
I have an azalea that has brown leaves mixed in with the green ones and it has not bloomed. What is wrong with this plant? I have several more plants close to it and they bloomed and look healthy. (Alachua)
There are a few things that could be going wrong with your azalea. I do not think it is a disease or insect problem though. Is it getting adequate water and fertilization? It might be in a spot where the irrigation or rainfall doesn't reach it. Also the pH level in that area could be too high especially if it closely planted to the foundation of your building. If so the fertilizer with the acid forming Nitrogen should help.
There is another problem that we often see on azaleas this time of year. Sometimes cold damage occurs on azaleas. Look inside the bush for split bark. If you see damage branches prune them out, and then fertilize it with an azalea fertilizer. This should rejuvenate the bush and getting it blooming for next year.
After one of our local hard freezes, a lot of our grass seemed to die back. The grass along the side of the garage and the back yard seemed to do better, and is largely, OK. Maybe it was more protected from the cold. I fertilized this past week. I am getting concerned that this grass may be dead. Do you think it could still come back? (Gainesville)
Cold damage of St. Augustine grass happens more often than most homeowners like to think. Especially in open or exposed areas we see a general browning of the turf. The blades of the grass turn brown or burnt looking following a hard freeze. This year we haven't had record breaking winter temperatures, although we had had freezes low enough to cause cold damage. When the temperatures warm up you will hopefully see a greening of the brown areas. You should have postponed the fertilization until after you saw a re-growth of the turf. Several varieties of St. Augustine are more susceptible to cold temperatures, such as Floratam and Seville. Prior to freezing temperatures, make sure that your grass is watered; this can help with cold tolerance.
The Cypress trees on my land are full of Spanish moss that has rapidly multiplied over the last 8 years. It really does seem that the moss is killing the cypress. Are you sure that I don't have to worry about removing it to protect the cypress?
The Spanish moss is actually a bromeliad that is considered an epiphyte. It does not take any nutrition or water from the trees that it is living in. The fact that it is thriving in your trees makes me think that something else is wrong with the trees. Since the moss is so heavy and could possibly break branches, you can try to remove some of it by using an extension pole. There are no products labeled for removing the moss from your trees. Try to do some detective work to find out what else could be going wrong with the cypress trees.
February 2004
I would like to grow a Gloriosa lily; will it grow in our area? (Alachua )
Gloriosa rothschiliana is a member of the lily family and is native to Africa. It is also called the flame vine or the gloriosa lily. It truly is a glorious lily with its exotic flowers of red and yellow. This tender bulb is a vine in our area. The vine climbs in a very interesting way. At the tips of the leaves are tendrils and they grasp a fence or trellis or another plant to climb towards the sun. The vine itself is not very 
strong, so it really does need support to thrive. Some of the most interesting specimens of the gloriosa lily that I have seen, are planted with a green hedge like a viburnum or a ligustrum. When the climbing lily starts to flower, it looks as if the green shrubbery is blooming with red and yellow flame vine. This vine is only marginally hardy in Alachua County. Usually they will die back to the ground and re-grow in the spring. They propagate themselves by underground tubers. If you grow them in a pot, you will easily see that the tubers will double themselves in a year. The best time to divide and plant the new tubers is in the spring. All parts are poisonous, so consider this when you site the plant.
Is this the right time to use a weed and feed in my lawn? (Gainesville)
This is the correct time to put on a pre emergent herbicide to control weeds before the seeds sprout. In the next few weeks (mid March) is the best time to do your spring fertilization of the lawn. You should apply the products separately to make sure you are getting the correct amount of herbicide and fertilizer. Many times the combination products have too much or too little of one component. The lawn at this time needs 1 pound of actual nitrogen per 1000 square foot, with 50% of that in a slow release form. If you were going to apply a 16-4-8 fertilizer you would put on 6.25 pounds of fertilizer per 1000 square feet.
The Pampas grass that we planted a few years ago is now huge! When can we prune it back? (High Springs)
In North Florida the leaves of the pampas grass are usually killed back by freezing temperatures. Even when the blades are brown they still do their job of providing a screen or hedge. The new grass growth will begin to emerge in the spring from the rhizome type roots that this ornamental grass has. Before the new growth begins is when you should do your pruning. Prune away all the brown leaves and dead material that has accumulated at the base of the plants. You should plan on wearing jeans and a long sleeve shirt as well as gloves. Protective glasses should also be worn since the blades of the grass will cut through the skin on the hands and legs and your face.
The pruning of the pampas grass is really the only trouble this plant will ever give you. They are a very low maintenance landscape feature. Pampas grass is rarely bothered by insects or diseases, and is quite drought tolerant once it is established. It will respond well to fertilization. If you add two pounds of a slow release fertilizer like per 100 square feet of hedge you will have a thick grass screen with plenty of feathery blooms in no time.
My grass lawn is covered with leaves. Should we rake them up, or can I leave them on the grass for awhile? (Gainesville)
With the nice cool winter that we have had so far this season, you grass should be dormant or at least not growing. Since the grass is not actively growing or even green, it is not necessary for it to get sunlight, so the layer leaves can stay on the lawn. In fact the layer of leaves may help to insulate the grass from hard freezes.
When you get ready to do you spring fertilizer application to the grass, rake all the leaves up and put them in your compost pile or in your landscape beds. Oak leaves make wonderful mulch. They will decompose faster if you run over your leave pile several times with the lawn mower to chop them up at least by half. If the leaves are so thick that they are beginning to rot or really trap water you can remove them now.
What herbs can I plant now? (High Springs)
Plant cool season herbs like dill, coriander, parsley, chervil, chives, garlic, rosemary, sage, sweet marjoram and thyme. Wait to plant others until danger of frost or freeze has passed. If you wanted to start the warm season herbs like basil, and mint from seed you could start them now on a sunny window sill or hot house so they would be ready to plant outside around the middle of March. If your herbs are growing well in the winter garden now remember to harvest leaves from your plants frequently to keep growth succulent and prevent them from going to seed.
January 2004
Two years ago I planted a redbud tree called Forest Pansy. It has really pretty burgundy leaves in the spring and summer. This year it started to decline and has a big split in the bark. What should I do? (High Springs )
I suspect that you have some old cold damage on the tree. This particular Redbud does best in north Florida, because it is used to a longer dormancy period. Often times in Alachua county we will have a warm spell in the middle of winter. When this happens trees can break dormancy early, and then are susceptible to the inevitable freezes that come in March and sometimes even April. The break in the bark might be the result of late freeze damage. To deal with the problem, you should simply take the wait a see approach. There is nothing that you can apply to the bark, just allow the tree to seal off this damaged area. When it begins to re-grow in the Spring prune out any dead branches, fertilize it with a general purpose fertilizer like 10-10-10 and make sure that the tree is watered during the year. If it continues to decline you could replace it with another redbud more suited for our area.
I understand that the Chinaberry tree is poisonous, should I remove the one in my yard? (Alachua)
The Chinaberry tree is definitely poisonous. Deaths have resulted in humans and livestock from eating the fruit. The ripe fruit is more toxic than the unripe fruit. The symptoms of poisoning can occur within an hour, and include abdominal pains and nausea, irregular respiration and death due to respiratory failure. The tree is a weedy chap and is an invasive plant in Florida. Birds have become intoxicated after eating the ripe or overripe fruits and the leaves and bark have been used to shock fish. It is related to the mahogany tree and it is also called the Chinese umbrella tree. There are many other appropriate trees for your landscape, which are not dangerous. Call the Extension Office (352 955 2402) and request Native Trees for North Florida (Circ. 833) for a few ideas for replacing your Chinaberry.
I have a lot of cacti in my house and most all of them are in terra cotta pots. A few of them have a strange white fungus stuff growing around the bottom drain hole. Any ideas what this might be? (Gainesville)
It would be useful to know what type of soil you are using. Since they are cacti, the potting media is probably pretty sandy. If your pots are very shallow you could be seeing roots emerging from the drainage hole.
More likely what is going on though, is the soluble salts from the fertilizer that you are using are leaching out on the sandy soil, and crusting on the clay of the pot.
High soluble salts are caused by the excessive use of fertilizers, frequent applications of fertilizer, and the incorrect use of fertilizer concentrates. Often we see symptoms on the leaves of the plants, in the form of browning or dieback of the leaf tips and margins. The root will have dieback or decay as a result of this salt build up.
The best way to avoid this is to use the proper fertilizer at the correct rate and frequency. If the pots are very large you should flush the soil by irrigating with clean water. Water the whole volume of the pot several times and allow the water to run out the bottom of the container. If your pots are small you should repot the plant with new soil, and soak the empty clay pots in water until the white crust is gone. It is a good idea to occasionally flush the soil of potted plants to make sure you are not getting a build up of fertilizer salts.
In the cold weather should I remove the fruit from my calamondin tree? Will it effect the fruiting for next year? (Alachua)
The very acid calamondin is usually grown as an ornamental tree. Outside Florida it is most commonly grown in pots as a souvenir house plant from Florida. The fruit resembles kumquats and the small tree is very bushy. It is relatively cold hardy and can easily be grown in Alachua County. The fruit stores well on the tree, but if temperatures are going to go below 28 degrees you should remove the fruit if you want to eat it. If by chance you leave the fruit on and in freezes, it should not effect the blooming for the following year. Do try to remove the fruit before the flowering begins.
Someone told me that Epsom salts were good to use as fertilizer is this true, and what does it do? (High Springs)
Many of us know that Epsom salts is great for soaking tired feet or an aching body, but it is true that it can be used to enhance our plants and gardens. Epsom salts is also known as magnesium sulfate. Magnesium and sulfur are both essential elements for plant growth, and are often found in complete fertilizers that you purchase at the store. Magnesium is considered a macro element, and sulfur is called a micro element (once called minor element), both of these elements are contained in the box of Epsom salt that you might have underneath the sink right now.
The magnesium in the Epsom salts is especially useful when dealing with citrus or non native palms. If you purchase a palm special or citrus special fertilizer you do not need to add additional magnesium, but if you just use an 8-8-8 type product the Epsom salts would definitely help.
Epsom salts can also be used on vegetable plants such as tomatoes. A soluble fertilizer that can be made from Epsom salts to feed tomato plants is made up by dissolving 2 cups of either a 6-6-6, 6-8-6, 6-8-8, or 8-8-8 analysis common fertilizer, 6 tablespoons of Epsom salts, and ½ teaspoon iron chelate in 1 gallon of tap water. This growing solution is then diluted to 2 tablespoon per gallon in water; the diluted growing solution is watered into the plant every few days. This is especially effective when using a soil mixture that is made up of a soiless type mix.
Roses, evergreen shrubs, and azaleas can benefit from Epsom salts. One teaspoon per inch of plant height during the spring is a great way to bring magnesium and sulfur to the plant. These two elements and all nutrients will be best absorbed by the plants if the soil pH is appropriate for the specific plants. Please note that the sulfur from the Epsom salts will not have an acidifying effect on the soil, like elemental sulfur or the acid forming fertilizers.
If your plants are needing a fertilizer boost, consider using Epsom salts as a enhancer to your regular fertilizing schedule. After you have worked in the garden, you can use the salts to soak your gardener's feet.
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