Weekly Home Horticulture Column
Key Lime Tree | Passion Flower Vine (6/30/2012)
Dwarf Indian Hawthorne | Yellow Tomatoes Splitting (6/16/2012)
Ginger Monster | Cucumbers - Pollination (6/2/2012)
Zahara Zinnias | Tomato Wilt - Fusarium (5/19/2012)
Tomatillos | Common Invasive Exotic Plants (5/5/2012)
Q. I have a key lime tree that for first time is loaded with fruit. I think that the limes are fully grown to size, and are getting some yellow color which I thought indicated ripeness. For a few weeks now I have been picking one to determine if it is truly ready. They seem to be very dry with little juice. What would be the reason for the lack of juice? I was so looking forward to key lime pie.
A. Key limes are definitely a Florida favorite. Ocala is probably too far north to grow key limes in the landscape, but many gardeners find them worth the extra effort of keeping them in a pot and protecting them from freezing temperatures. The problem you are describing is called granulation, or premature drying. It is caused a few different reasons. You may have waited too long to harvest the limes and they could have dried out on the tree. But since you have watching them so closely I don’t think this is the cause. More than likely the dried key limes were caused by an inconsistent watering program during the fruit development. Make sure the lime tree gets 1 inch of water a week. You can break this into two waterings over the week. Also fruit drying is worse in young trees. As your key lime tree matures it will be able to carry a more consistent delicious crop, juicy enough for pie. For more information on this and other citrus issues request the document “Citrus Problems in the Home Landscape” from your local UF/IFAS Extension Office or at www.solutionsforyourlife.com
Q. Our neighbors have passion flower vine plants which shoot runners into our yard. These runners have started showing up in increasing numbers. We don't use poison to control weeds in our yard, and my husband has tried to deal with this sucker by sucker, one at a time. Despite his efforts it is getting ever worse.
A. Our native passion vine (Passiflora incarnata) is a wonderful plant to use in your Florida friendly landscape and in your butterfly garden. It thrives in sunny locations and does best during the summer months. Your neighbor must be growing his on a fence or a trellis close to the property line. The passion flower blooms are striking with their deep purple color and intricate detail. Most butterfly gardeners include them in their landscape, because the leaves are the larval host plant for the Gulf Fritillary and the Zebra Longwing. Usually the Gulf Fritillary caterpillars keep the foliage of the vine eaten down off and on during the summer.
You have discovered the only drawback about the passion vine. It does like to creep and spread about. Just when you have pruned back a shoot, another plus a few will return in its place. Since you do not want to use herbicide you will have to keep pulling or pruning back the shoots. For a more permanent solution you could also put down a weed barrier and mulch on top of it. The weed cloth will prevent the shoots from breaking through the mulch. This will help to stop your neighbor from sharing his passion for gardening.
Q. What is going on with the Dwarf Indian Hawthorne this year? They all look bad. They are sparse and the leaves have spots. Many in my landscape have died. Can you help?
A. Many Dwarf Indian Hawthorns in North Central Florida are showing symptoms of a disease called Entomosporium leaf spot. I know it is a big name for troublesome leaf spots, but the normally hardy Indian Hawthorns are taking heavy damage from this disease. First we see distinct circular red lesions with gray centers on the leaves. Badly infected leaves then fall to the ground and the plant thins out. In the worst cases there is dieback of stems and branches. The fungus can live on fallen leaves so it is a good idea to rake the dead leaves up and get rid of them.
The way that you care for the plant definitely influences the severity of the leaf spot disease on the bushes. Good cultural practices are probably the most important way to reduce Entomosporium leaf spot in your Dwarf Indian Hawthorne. The disease is favored by moisture on the leaves. Make sure the irrigation is not directly hitting the leaves or keeping the shrub wet. The fungus infects young tender leaves more readily than older leaves, so try to keep your pruning to a minimum to prevent frequent flushes of fresh leaves.
There are some varieties of Indian Hawthorne that are more resistant to Entomosporium leaf spot. When shopping for new plants or replacements, select varieties like Olivia, Eleanor Tabor, Indian Princess, Gulf Green, Georgia Petite and Georgia Charm.
Infections occur in the milder weather so the best time to use a fungicide is in the spring or fall. Select a fungicide that contains the active ingredients Propiconazole or Triadimefon and Trifloxystrobin and follow the label instructions. For more information about this disease, visit www.solutionsforyourlife.com the UF/IFAS informational website.
Q. I have started harvesting yellow tomatoes from my first raised bed garden & they taste great, but a lot of them are splitting before they are ripe. Is there anything I can do to prevent the fruits from splitting?
A. Some varieties of tomatoes are more prone to splitting than others. Usually the yellow varieties like yellow pear and Taxi are fine. This year though we have had very dry growing days followed by the occasional Florida down pour.
When the plant absorbs water in excess and moves the water to the tomatoes, the fruits can split. In order to prevent this, harvest the fruit just before they are completely vine ripe and let them ripen on the kitchen counter. When you are selecting what tomatoes to grow for next year, check the notes on the variety and select one that says “crack resistant” or split resistant.
Q. I have a bed of gingers that is always very beautiful in the summer. However, this year, I have noticed that something is snipping some of the plants off, right at the base. Whatever it is has pretty much gotten all of my white fragrant ones, and is now attacking some of the rest. This is the first year I have had this problem. Do you have any thoughts or suggestions as to what it could be and what I can do about it? Is there some new Ginger Monster out there this year?
A. This is more than likely the work of the pesky squirrels. When the new ginger stems or canes emerge from the ground they are fresh and full of water. The squirrels must think it is a tasty asparagus spear sprouting just for them.
In years of drought this sort of damage is worse, because the wildlife is struggling to find water anywhere they can. Sometimes we see the feeding on bark and leaves as well. To stop the damage you can try to use commercially available taste repellents. They are either granules or sprays that taste terrible. Chewing animals normally leave the plants alone for a while. Also you could try excluding them from the area by fencing off the ginger in a wire cage.
Live trapping is another option. Use a ‘havahart’ trap (available at the feed store or large hardware store) to capture the squirrels. But then what do you do with the ginger monster? You can relocate them within the county but you must have permission of the property owner before you do so. For more information about pesky squirrels and other gardening issues visit the UF/IFAS website www.solutionsforyourlife.com
Q. Why do my cucumbers look more like miniature pickles? They have a weird curled shape too. What is the problem and how do I correct it?
A. When the fruit of a cucumber or another member or the cucurbit group (squashes and pumpkins) do not form or fill out properly it is usually a problem with pollination. These flowers are normally bee pollinated and you may not have enough bees visiting the flowers of your cucumber. If you have been using broad spectrum insecticides in and around the garden, during the middle of the day stop. You may be killing the bees. Also I encourage you to plant more bee attracting plants to your garden such as gaillardia, coreopsis, agastache, verbena and allowing your parsley, dill or cilantro to go to flower.
In the mean time try to hand pollinate the flowers with a paint brush or q-tip, by bringing pollen from the male flower to the female flower. Call the Alachua County Master Gardener desk 352 955 2402 and they will send you a great guide on how to hand pollinate your squash.
Q.What flowers can I plant for summer to give my garden some color? Also they should attract butterflies and pollinators too.
A.Annuals are an inexpensive way to bring intense color to your landscape and there are quite a few warm season annuals that can be planted now. So if you are thinking about what can grow in the heat and in the full sun, try marigolds for a punch of yellow or orange. Hot colors like red, yellow and orange grab attention, these flowers look great by the front door or in containers on the deck. Blue salvia and purple angelonia are a few of my choices to provide months of cooling colored flowers to your landscape.
My new favorite annual for 2012 though has to be Zahara Zinnias. Stop what you are thinking; these are not your grandma’s zinnias. The Zahara series is wonderfully heat, drought and humidity resistant; perfect for North Central Florida. They grow to about 12 inches tall and come in single and double forms with flowers 2-3 inches across. You will be able to pick them up as seeds from the catalog companies in great colors like white, yellow, starlight rose, double cherry and double fire. Unlike the zinnias that I have grown in the past they are very resistant to diseases like mildew and leaf spot. Butterflies are big fans too and I have even seen a hummingbird come to these new old fashioned flowers. Grow any zinnias in full sun and water to get the seeds going and stand back and enjoy the color.
Q.I have had a few tomatoes plants simply wilt and die. They are getting plenty of water but they are just limp and dying. Help.
A. Tomato plants wilt for a variety of reasons, and all of the reasons are not good news for any tomato grower. The most common wilt that we see is caused by a fungus called Fusarium. The disease begins with yellowing of the lower leaves. The yellowed leaves gradually wilt and die. Usually the entire plant may decline and die. The fungus destroys the vascular tissue of the plant and it cannot move food or water through the branches. Fusarium fungus can be in the soil or introduced by wind, water, or equipment. There really isn’t a cure for this problem, we can only prevent it by using resistant varieties. The back of the packages on your tomato seeds let you know what diseases they are resistant too. Another fungal wilt that Florida gardeners deal with is Verticillium wilt. It is similar to the Fusarium wilt, except that the plant seems to recover during the night and then wilts back down during the day. The plant is stunted and the fruit is small. Look for resistant varieties of tomatoes such as ‘Celebrity’ to avoid this disease next year.
We also see bacteria wilt in tomatoes. It is worse in moist, warm, infertile soils. The disease appears as a rapid collapse and the death of the plant. If you were to cut the stem near the soil line you would see a dark hollow stem. Remove and destroy diseased plants as soon as you can. There are not many tomatoes resistant to bacterial wilt. If you have had this problem, avoid planting in sites which the disease has been a problem in the past. Crop rotation is important in coping with all of these wilt diseases avoid planting tomatoes in the same spot year after year. For more information on these and other tomato woes visit the UF/IFAS website www.solutionsforyourlife.com or call the Alachua County Extension office at 352 955 2402.
Q. Our tomatillos are developing wrinkled leaves. Not all are affected. Do you think this is a disease or a soil issue?
A. Tomatillos are closely related to tomatoes. The fruit is green and has a papery outer jacket or husk. Some people call them husk cherries. Tomatillos are usually easy to grow in your north central Florida garden. They will need similar care to a tomato plant but they usually are a little tougher against pests, diseases and weather.
Crinkled leaves on young plants of tomatillos and peppers could be caused by a couple of things. This first is broad mites. This type of mite feeds along the leaf vein and cause the leaf to deform. Use an insecticidal soap spray to control the broad mites. The other problem that could cause leaf crinkling is a virus like mottle virus or yellow mottled virus. These diseases come on the seed or are in the soil and are spread by clippers (mechanical) or insects. You first notice deformed new leaves and then yellowing of the older leaves. Normally, when you have a virus in your vegetable plants the recommendation is to rogue the plants or to pull them out. In the case of mottled virus it won’t cause the plant to die completely and the symptoms may be very mild. UF/IFAS expert Aparna Gazula says, “If the virus affects young plants the production can be greatly reduced”. In some cases you can prune off the most affected leaves and the plant will recover with new growth and still produce some tomatillos for your ‘salsa verde’.
Q.I live in an older neighborhood of Gainesville and have a quite a few plants that I know are invasive weeds. Specifically I have Mexican petunia, Boston fern and ardesia. I need to get them under control because they are taking over the yard. Is there an organic way to do this?
A.You are growing some of the more common invasive exotic plants that we have in North Central Florida. An invasive exotic weed is a plant that has escaped from cultivation, moved into natural areas, and is displacing our native plants. These plants were often introduced from the horticultural trade before we knew how out of control they could get. If you think you are growing invasive exotics in your yard check the IFAS website www.solutionsforyourlife.com or the Florida pest plant council website www.fleppc.org for more information.
Normally herbicides are recommended to remove these plants from your landscape but that isn’t exactly organic. Persistent digging and hand removal will work too. It just takes longer. Try to get as much of the root as possible and dispose of the plants in the regular waste pick up. Do not drop them in a natural area they will just take root and the problem will start over again.
If you would like to know more about invasive plants and how to remove them from your landscape the attend the free class Controlling Invasive Exotic Plants at the UF/IFAS Alachua County Extension Office, 2800 NE 39th Avenue, Gainesville on May 9th at 6pm.
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Purple Passion Flower Vine
Yellow Tomatoes Splitting
Cucumbers Poorly Pollinated
Fusarium on Tomato Plant