Ask Wendy
Weekly Home Horticulture Column
Summer 2004
- Agapanthus
- Banana Trees
- Blueberry Bushes
- Camellias
- Cedar-Quince Rust
- Crape Myrtle
- Dogwood Tree
- Mona Lavender Plectranthus
- Pears
- Perennial Peanut
- Sycamore Tree
- Wasps
- Willow Tree
August 2004
My willow tree is usually beautiful, but this year all the leaves have turned yellow and there are brownish spots all over the leaves. Is there anything I can do? (Lacrosse )
The problem that you describe sounds like Willow rust. This disease will cause the tree to lose its leaves but will not seriously harm your tree. Severely infected leaves will have many yellow or brown spots and will fall off. The diseases is spread by rain and wind during the trees growing season. Normally willow trees thrive under wet conditions, but rain makes the rust disease worse. The spores of the fungus will survive winter on the fallen leaves and reinfect the tree the following spring. So the best method of control is to rake all the leaves in the fall and keep the tree healthy with proper fertilization, watering and mulching. We don't usually recommend a chemical control for this problem, because it would not be practical to spray a large tree.
I have planting of agapanthus that just refuses to bloom. I think that they are getting too much sun. (Gainesville )
Agapanthus or Lily of the Nile, perform well in full sun so I don't think that the exposure is the problem. Fertilization and irrigation are key for these bulbs. Some guides recommend fertilizing monthly during the growing season. Regular watering will also help since they thrive in slightly moist soil. Also, Agapanthus will bloom best when they are crowded. So if you have been dividing the bulbs to fill out the bed; stop and let the bulbs grow in closely, this should help get the purple blue or white clusters of flowers, blooming in the late spring. If this still doesn't work, you could try society garlic (Tulbaghia ) as an alternative that will bloom all summer long.
How do I know when my pears are ready to pick. They never seem to soften up. (High Springs)
August is the month that two of our local fruits crops are ripe and ready for picking. Sand pears and muscadine grapes are easily grown in the backyard orchard. They require very little insect and disease control and will be relatively drought tolerant once established in the landscape. Because the pears that we grow in Alachua county are hard pears or sand pears it can be difficult to tell when they are ready. Pick the pears when they are full sized, about 6-10 days before they would drop off the tree naturally. You can test a few fruit by picking them from the tree and evaluating them for juiciness and sweetness. Soon you will be able to tell when they are ready to eat. To keep the grittiness of the pears down you can store them at 60-70 degrees.
If you don't have a grape vine or pear tree at your home, these fruits are available from area farmers. Call the Alachua County Extension Office for a list of growers or visit the farmers markets
Other fruit gardening chores need to be tended to this month.
- Fertilize blackberries soon after harvest with 1/3 pound of 10-10-10 per plant. If you haven't already pruned the blackberries this year it is a good time to cut them back to the ground. This will insure fruiting for next year.
- Rabbiteye Blueberries should be pruned now to generate new fruiting growth for next year. Pruning established plants means cutting out the older canes and eliminating the twiggy growth in the top and outer area of the bushes.
My banana trees are producing a real crop for the first time. Is it best to cut off the red thing off the bottom once it has quit producing fruit? It is still making flowers and although the hummingbirds like them, I thought it might take energy away from the fruit. Gainesville
Bananas will grow in Alachua County so long as it stays hot. They flourish under uniformly warm to hot conditions. The tree grows best at temperatures between 78 degrees F to 82 degrees F and fruit develops best at 84 degrees F to 86 degrees F. The tree growth slows below 60 degrees F and stops at 50 degrees F, so it is important to get your fruit ready and picked before our temperatures cool off in the fall. In the winter most banana plants here die back to the ground when the temperature goes below 28 degrees.
Banana plants need fertile conditions and an abundance of soil moisture for best growth and production. The type of growth the plant makes in the first 3 to 4 months determines the weight of the bunch and the number of hands. So, it is essential to provide the best of care during this period. Use a fertilizer that has plenty of potassium like 9-2-12, often during the growing season.
If the spring and summer are warm enough and you have watered and fertilized often, the tree can make a bunch of bananas. It may just have a few hands of the fruit and then a long stem with a cone of purple leaf like bracts. This cone contains the male flowers. Bees and hummingbirds enjoy it but it is taking some resources away from your banana fruit. In the banana plantations in Central America this is not a big deal, but in Alachua County we need to rush the development of your fruit along before the weather turns cool (below 60). So it is ok to remove the male flower, don't get any of the sap on you- it really stains. Some people even cook with this part of the banana stalk. The bananas will continue developing and when they are full sized and plump it is time to cut the bunch of bananas from the tree. This tree will only produce one bunch of bananas during its life. Younger shoots will emerge from the base of the tree; later remove the older tree to allow space for the new
June/July 2004
I saw but did not catch what I believed to be an ant? It was approximately 1 inch in length, mostly orange with a black band around the abdomen, as well as other black accents and rather fuzzy. Was this an ant or a wingless bee or wasp?
As you suspected these insects are wasps, not ants. The females are wingless and covered with dense hair, and at first glance resemble ants. The red velvet ant is the 
largest velvet ant species, reaching about 3/4 inch in length. They are black overall with patches of dense orange-red hair on the thorax and abdomen. Males are similar but have black wings and cannot sting. Lone females can be found crawling on the ground, particularly in open sandy areas. Adults are most common during the warm summer months. Larvae are solitary, external parasites of developing bumble bees, immature wasps, and some species will go after white grubs. Humans are not often stung by velvet ants, but when it does happen, the female is accidentally stepped on with bare feet or trapped against the body in clothing or bedding. The sting is quite painful and similar to a wasp bite. In Texas they refer to some species as "cow killers" to describe the painful bite. Control is not recommended for these insects since they are solitary and roaming.
Someone is giving me a crape myrtle tree. It is about 4 ft. tall and a good bush. Should I move it now or wait for cooler weather? (Gainesville)
I would recommend waiting until the cooler months to transplant the shrub. In the case of the crape myrtle it would be best to wait until the tree goes dormant (looses its leaves) to make the actual move. Since you have plenty of time you can do a root pruning about 4-6 weeks before you move the plant. To root prune, make an 18 inches diameter circle around the trunk with a sharp shovel. Slice the shovel into the soil about 6 to 7 inches deep, until you have a complete circle. During the next weeks, water the plant well. Then on moving day cut another circle a few inches out from the original one and gentle lift the root ball out of the soil and move to the new location. The success of the transplant will depend on keeping the root ball moist during the next months. Make sure that the roots stay moist (not overly dry), and you should have a healthy new shrub in your landscape.
I love the yellow flowering ground cover that I'm seeing around Gainesville. There is quite a bit of it near the IFAS office on campus and in the lawn at the Millhopper Library. No one seems to know what it is or where it can be purchased. We have a very large lawn with full sun exposure and I would love to plant it there. (Gainesville)
What you are seeing is the great turf alternative called perennial peanut. The plantings on the university campus are mixed with Bahia grass, so it actually looks like the grass is in bloom with bright yellow flowers. Perennial peanut has great promise an ornamental groundcover planted just by itself, because of its high resistance to drought, nematodes and diseases, in addition to its minimal fertilizer needs. Perennial peanut evolved in tropical conditions and is well adapted to our area. It will grow as far north as the Georgia state line, with some freeze damage. It does return as soon as the warm weather returns though. It can be mowed but does not need to be maintained at a high level. This spreading ground cover does best in full sun and when the weather is hot and humid. It will tolerate partial shade with little or no mowing. This forage plant turned ground cover can be used in many different soil types, but the ideal soil pH range is between 5 and 7.5.
It is spread by rhizomes or underground stems and not by seeds or peanuts. Usually small plants or plugs are soil at area garden centers like Harmony Gardens in Gainesville or from Haystack farms on the internet. Plant the plants or plugs using a 12 inch to 18 inch spacing interval. Weed control is very important when establishing the planting. The closer you space the plugs, the quicker the grow in time will be. With good watering and weed control your planting of perennial peanut will have a great summer of yellow blooms by next year.
Is it too late to prune my Blueberry bushes? The just recently stopped producing fruit. (High Springs)
The time is getting close but there is still time to prune them without damaging next years crop. With sharp pruning shears remove the oldest 1 or 2 canes of the bush to the ground. Then gently prune the tops of the other branches. Never remove more than 1/3 of the bush at a pruning time. Give your plant a fertilization of 16-4-8 or an azalea fertilizer. This is also a good time of year to freshen the mulch underneath the blueberry plantings.
Our 3 year old sycamore tree is covered in cup shaped leaves. They are perfectly healthy otherwise, and have no spots on them. (Gainesville)
These leaves that are somewhat malformed and cupped downward also have an excess of the leaves' natural hairy fuzz. This is a sure sign of herbicide injury. It was very likely caused by applications of "weed and feed" products to the lawn. Dicamba or 2,4D, commonly found in "weed & feed" products, were probably the herbicides at fault. Sycamores are particularly sensitive to damage from these two herbicides.
The downward cupping of the leaves is not critical. After all, the tree will soon be losing these leaves in preparation for winter. The real damage from these lawn herbicides happens to the trunk of the tree. Both herbicides can lead to damage of bark tissues and the emergence of bark eruptions on the main trunk, usually more extensively on the lower portions of the trunk. The bark loses its beautiful mosaic pattern and smooth appearance. It becomes rough and fissured. Immediately beneath the eruptions, the bark tissue is pink and spongy. Beneath the eruptions, the inner wood becomes dark brown. This damage may later attract a borer, the American plum borer, which then causes even greater damage to the bark and trunk tissues.
Dicamba and 2,4 D can cause damage to sycamores even when applied at the correct rate, but greater damage occurs if they're over-applied. Over-application often occurs when home gardeners don't calibrate their drop-spreader or sprayer before applying a "weed and feed". As a rule, 2,4 D and dicamba should not be applied in a general application to the lawn over the root zone of sycamores. Spot treating weeds is safer for the sycamores and more economical
I have tried to air layer some camellias. This is the procedure I followed. I girdled about a 1" area on a branch, covered it in sphagnum moss, then plastic wrap tied at both ends to seal it, then covered that with aluminum foil. I did not use a rooting hormone. The area has not started making roots yet. They do have a bump at each end of the cut area like scar tissue. The leaves of the branch still look healthy. Is there still hope that they will root? Do I need to do something else - like get a rooting hormone? Girdle the branch again? (High Springs)
It sounds like your timing and technique was perfect. We recommend air layering camellias in May. But next time you air layer a camellia do use the rooting hormone. My advice for your current air layers is a measure of patience and stop peeking at the stem. The camellias take quite a while to produce roots and you should not expect to see results until the fall. The air layers should be ready by October to be potted. The fact they are showing some callous tissue is a good sign. Just try to be patient until October.
I am looking for a plant that blooms in the shade, and I am tired of impatiens. Can you recommend anything? (Gainesville)
T
here is a plant that is new to the nurseries that will definitely be a great addition to your shady landscape.
It is called Mona Lavender Plectranthus. This plant is quite spectacular with it's 6 inch long spikes of lavender blossoms that keep on blooming through out the growing season. It is grown as a root hardy perennial here in Alachua County. It can be used as a bedding plant in shady areas or in patio and porch displays. This interesting plant has numerous stems growing to a rounded plant 2 feet tall and wide. The leaves are deep green with purplish veins, slightly curled at the edges with short coarse teeth and growing to 2 inches long and 1 inch wide. It does best in filtered sunlight or a shady spot. The Mona Lavender prefers a moist soil, so you will need to water it twice a week or so; slightly less than the thirsty impatiens.
This Swedish ivy relative will produce non stop flowers during the growing season especially if you fertilize in-ground plantings every six to eight weeks with a general garden plant food. Propagation is a snap with this plectranthus. Just take cuttings, treat with rooting hormone and place in moist soil. Pruning will encourage a compact growth habit, and removing spent blossoms (dead heading) will bring on more blooms.
The Mona lavender doesn't have many insect pests. But, if it gets mealy bugs, just treat them with a soapy water spray. The plant will take some cold temperatures, but frost protection would be helpful during very cold periods.
I planted a dogwood tree three months ago. Now the leaves have spots on them. I have been trying to keep up with the watering. Can you help? (Gainesville)
There a few things that could cause a newly planted dogwood to have leaf spots, or show leaf damage. The first thing that you should try to check on is how much water the plant has been getting. It had been a very dry spring in Alachua County, so the root ball of the plant drying out could be a reason for leaf spot of leaf death. Also where you planted the tree could be causing some leaf problems. Remember that dogwoods are basically an under-story tree and do not thrive in full sun hot conditions. Leaf scald, like sunburn, is often seen on dogwood leaves, especially young specimens.
Leaf spots can also be caused by fungal diseases. Spot anthracnose is a fungal disease that is seen on leaves and flowers. This is not the type of dogwood anthracnose that is killing trees north of Georgia; it is only seen on the leaves and will not devastate the tree. Septoria leaf spot will cause purple or burgundy lesions during the summer season. Powdery mildew will infect dogwood leaves too. You will see symptoms of this disease as a gray cast to the leaves along with spots. Rake away any of the fallen leaves if you have these types of problems. If the problem reoccurs you could spray with a fungicide like Immunox.
Be careful with herbicide products around your dogwood trees, especially a fertilizer herbicide mixture like weed and feed. They are very susceptible to herbicide damage. Distorted, curled or twisted leaves could be the result of weed killer over spray.
Planting depth of the tree is very important for its over all health, double check that you didn't plant the tree too deeply. It should be planted slightly higher than it was growing in the nursery pot. A mulch layer of 3-4 inches around the drip line of the tree will help to conserve soil moisture for the tree. It will take 6 months to a year before your tree is truly established in its new home. Watering on a routine basis will help the transition go smoothly.
All the little pears on my trees look like they are sprouting orange hair. What is going on here? (Lacrosse)
This is a symptom of a fungal disease called Cedar-Quince Rust. It occurs on a wide range of plants related to pear like apple, quince, crab apple, as well as evergreens like cedars and junipers. In order to survive the fungus must move from an evergreen host like a cedar to a deciduous host, in your case, a pear tree. If you have ever seen an orange jellylike growth on a cedar you have seen the other obvious stage of this fungus. This fungus can infect the leaves young branches and fruits of a pear tree, but most people see it on the small just forming pears. It does ruin the fruit for this year. You should attempt to remove as much of the infected twigs, and fruit as possible. Take the material away from the area. If possible avoid planting pears around cedar trees and vice versa. In fact a similar disease called the cedar apple rust of apple trees used to be a problem for commercial apple orchards in the north until they removed any cedar trees with in a mile of the apple production area, and started using resistant apple varieties. Cutting down all the cedar trees in your neighborhood is not a recommended control measure though. There are a couple of fungicides that you could use early on in the spring next year if this has been a recurrent problem. When the blossoms of the trees are just swelling you should apply a captan spray or a copper sulfate spray. This will help to keep the cedar quince fungus under control.
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