Weekly Home Horticulture Column
Poison Ivy | Fertilizer (9/20/2014)
Daylilies | Poet's Jasmine (9/6/ 2014)
Passion Vine | Basil Plants (8/23/2014)
Walnut Caterpillar | Spittlebugs (8/9/2014)
Redbud Leaf Folding | Establishing Sod (7/26/ 2014)
Rain Shutoff Device | Cucumbers (7/12/2014)
Q. The poison ivy in our natural area is really taking over. While walking through the woods, I must have come in contact with the nasty vine. Even though I washed the clothes I was wearing, I still got a rash on my ankles the next time I put my gardening pants on. How do you deal with this?
A. The sap of poison ivy, which contains the oil, urushiol, will stick to more than just your skin. It will stick to garden tools, camping equipment, clothing and even shoe laces for months. Washing the urushiol out of clothes is difficult because the oil is not very soluble in water. Wash contaminated clothes in a strong soap like Fells Naptha laundry bar. Rinse with several changes of water, and rinse the machine between loads. Do not put your gardening pants in the dryer, but allow them to dry on the line for several days in the hot sun. To get the sap off of your skin, there are specially prepared cleansing agents like Tecnu Skin Cleanser, Tecnu Extreme Medicated Poison Ivy Scrub and Zanfel that remove much of the rash-causing oil if applied to the skin within four to eight hours of contact.
Q. I know that it is time to fertilize my St. Augustine grass for the fall. When I went shopping for fertilizer at my local discount store, I noticed that the usual bag I buy is not at a discount at all. In fact, it seems really expensive. What is going on here?
A. You are right. UF/IFAS Extension recommends fertilization for our lawn grasses during September to keep the grass healthy and growing through the fall. If you choose a fertilizer with 50 percent of the nitrogen in a slow-release form, it will give the grass a slow feed throughout the rest of the year.
You will want to apply no more than 1 pound of nitrogen per 1,000 square feet of lawn grass. If you were using a 10-0-10 fertilizer, you would apply 10 pounds of actual fertilizer, or if you choose the 15-0-15, you would apply 6.5 pounds of fertilizer per 1,000 square feet of lawn. It is critical to really measure your turf area so you know how much to apply. Too much fertilizer can lead to cultural problems like thatch and insect issues. Also, the more you fertilize, the more you have to mow. Slow-release nitrogen will give a slower feed to the grass, prevent leaching and help prevent pollution of our ground and surface waters.
Fertilizer prices are tied to petroleum prices, so you can understand why you have seen a leap in cost. Also, marketing plays a big part in the cost of the fertilizer products. You may have noticed an upswing in primetime commercials for fertilizers, as well. Researchers at the University of Florida IFAS Center for Landscape Conservation and Ecology have found that consumers are more willing to pay premium prices for fertilizers that are labeled as ecofriendly, organic or pet friendly.
By shopping at commercial suppliers and small feed stores, you will find lower prices than those at your usual store. Fertilizer suppliers such as GreenSouth, John Deere Landscapes and Growers fertilizer normally deal with professionals, but they are open to the public as well. They may not be as conveniently located as your local big box store with the same hours, but they have many different types of fertilizer to choose from.
For help with figuring out fertilizers, visit the UF/IFAS Extension website at www.solutionsforyourlife.com.
Q. Is this a good time to divide my daylilies? Mine are getting overcrowded.
A. September is the best time to divide and replant perennials and bulbs, especially daylilies, and amaryllis that have grown too large or need rejuvenation. Daylilies multiply fairly rapidly, and plant division is an easy way to propagate them. If mats of daylilies become too crowded, flower production will be affected. Division is best done immediately after the flowering season. Dig the entire clump and shake or wash off the soil without damaging the roots. Separate the clumps by pulling apart or cutting sections of the fans of leaves. The old portions of the roots should be pruned to promote the formation of new roots. After the plant is divided, replant the fans in soil that has been improved with organic matter, and make sure to water the plants as they reestablish. Plant daylilies 18 to 24 inches apart to give them plenty of growing room. When spaced this way, daylilies will usually not need to be divided for three to five years. For more information about daylilies, visit the University of Florida/ IFAS Extension website at www.solutionsforyourlife.com.
Q. I just received a poet's jasmine as a gift. I am not sure how to grow it and how it will do in North Florida. Please advise.
A. Poet's jasmine is a vine that is winter hardy in USDA hardiness zones 7-10. Since we live in zone 8 or 9, depending on how north you are in North Central Florida, it will grow very well for us.
Also known as Jasminum officinale, this climbing vine produces 1-inch-wide tubular flowers in the spring and summer. The fragrance is described as intense but not as overwhelming as night-blooming jasmine (Cestrum nocturnum). When the plant is finished blooming, a gentle pruning will help to shape the vine and encourage new growth and flowers for the following season.
Grow your poet's jasmine in full sun in the ground or a container. It will do best in slightly moist soil. Fertilize with a slow-release formula in March or April. You will find poet's jasmine a fragrant addition to your landscape. For more information about vines or fragrant plants, contact the UF/IFAS Alachua County Master Gardeners at 352-955-2402.
Q. I knew I had a native passion vine growing on my fence in the natural area of my yard. This summer I noticed that it produced a fruit. Is this passion fruit? Can I eat it?
A. You are growing the passion vine Passiflora incarnata that is native to Florida and much of the Southeast United States. This vine produces one of the most beautiful flowers we see in Florida. The flower is 2-3 inches in diameter and has purple and white petals.
Originating from the center of the bloom is a delicate fringe of purple filaments. The very exotic blooms are seen during the spring, summer and fall. The passion vine's lobed leaves are a favorite larval food for butterflies such as the Gulf Fritillary and our state butterfly, the Zebra Longwing. Most butterfly gardeners hardly can grow enough passion vines to keep up with the hungry larva.
You have discovered the fruit of the native passion vine known also as the maypop. The fruit is about the size of a chicken's egg and light green. It is very light and full of air, and if you stomp on them, they "may pop." The fruit is loaded with seeds, and has a little bit of edible fruit close to the skin. The truly delicious passion fruit is a more tropical passion vine known as Passiflora edulis that are grown in sub-tropical Florida. Some North Florida gardeners have tried it and had success for a couple of seasons, and then lost the vines in a freeze.
Your maypop vine is a nice addition to your natural area. It will bloom beautiful flowers and attract loads of butterflies. For more information about native plants, contact the University of Florida IFAS Alachua County Master Gardeners at 352/955-2402.
Q. My basil plants look terrible. They grew really well during the spring, but now they are light green and have made a lot of flowers. Can I fix them?
A. The wonderful aromatic leaves of basil are a welcome herb in our spring and summer garden. Basil is a warm-season annual and will grow very well from March until the end of summer. They do benefit from light fertilization every three weeks during the year, which would help to fix the light-green leaves.
When you see the plant beginning to flower, clip back the buds. This will encourage new growth and provide you with more leaves to bring in the kitchen. If you do let the plant go to flower and to seed, the reserves and energy in the plant will be transferred to the maturing seeds. Your plants have already gone to seed. Let the seed heads mature and save the seed to plant next spring.
There still is time to grow another crop of fresh basil in August, September and October, if you plant transplants or get seedlings going very soon. Choose from different basil types like Thai basil, purple leaf basil and cinnamon basil to add a little interest in your herb garden. For more information about growing herbs, visit the University of Florida IFAS Extension website www.solutionsforyourlife.com.
Q. Our winged elm tree has lost all of it leaves from the top down. When we looked closely at the tree, we noticed hairy lined caterpillars all over the branches. What are they, and what should we do?
A. The caterpillar you are seeing is the walnut caterpillar, and folks across the northwest portion of Alachua County are reporting damage from this pest. Walnut caterpillars often are seen in oaks and other hard woods like pecans, hickory and elms. They feed on leaves and young stems and can easily defoliate a tree.
Their habit of moving up the tree en masse is particularly disturbing to tree owners. We normally see a couple of generations a year, so this may not be the last we see of the walnut caterpillars this year. Controlling these caterpillars is not usually practical because you would have to spray pesticide so high into the trees. In general, most trees will survive an infestation. If you have a high-value tree, consider calling a pest control company that would have the equipment to spray an organic control such as Bt.
Contact the UF/IFAS Alachua County Master Gardeners at 955-2402 for more information about pests in the landscape.
Q. I have noticed little wads of foam on my marigold plants and in my grass. It looks gross, but I am not sure if it is harming the plants. What is this?
A. You are seeing the signs of spittlebugs. This is an insect that feeds on many different plants, including ornamentals, weeds and lawn grasses — especially centipede grass. You might notice the adult form of the two-lined spittlebug hopping around. They are about ¼-inch-long and are black with two red stripes across their back. Sometimes they will fly up when you mow the lawn.
The immature forms, or the nymphs, encase themselves in a white foamy mass on leaves or branches. This protective spittle is how the bug got its name. Spittlebugs have piercing mouth parts that suck the sap out of the plants. The nymphs are harmful to landscape plants because they have to remove so much fluid to feed and to make the foamy mass. The adults cause damage, too, because in addition to feeding on the plant, they release a toxic substance into the plant.
If you have just a few spittle masses on your marigolds, blast them away with the hose or remove them with a paper towel. However, if you are noticing a decline in your centipede grass that appears as purple or yellow stripes running vertically on the grass blades, you may need to treat with an insecticide. Look for a product that is labeled for spittlebugs in turf and contains bifenthrin, or cyfluthrin. Be sure to read and follow the pesticide label instructions. Lawns with thatch, and lawns that are over-watered, are more prone to problems with spittlebugs, so you might need to evaluate your turf and drop back on the watering. For more information about spittlebugs and other lawn pests, visit the University of Florida IFAS Extension's website at www.solutionsforyourlife.com.
Q. I noticed the leaves of my small redbud tree are folded in half and browning. When I opened up the leaf, there was a caterpillar eating! What is this bug, and what should I do? If it grows into a nice butterfly, I don't necessarily want to kill it.
A. We don't always see these caterpillars because they are so well hidden in the leaves. Your redbud leaves are being eaten by a moth larva called, appropriately, the redbud leaf folder.
The caterpillar sews itself a little hidden pouch to skeletonize the leaves of the redbud tree. Usually, they go after just a few leaves and treatment isn't necessary. This insect overwinters in the fallen leaves of the redbud, so a management strategy would be to rake up the leaves from under the tree and dispose of them in the compost pile or yard waste. For more information about landscape pests, contact the UF/IFAS Alachua County Master Gardener volunteer at 352/955-2402.
Q. When will it be too late for establishing St. Augustine sod, evergreen shrubs and trees?
We hired a landscaper in the spring, but he's delayed the project, and now he says he can do the work in August. We're re-sodding and replanting all shrubs and five to 10 small trees.
A. In Florida we can plant sod, shrubs and trees at any time during the year. Ideally, the best time to plant would be in the early spring, especially if we are having good rains at that time.
This gives the new plants time to become established and strong before going into a summer drought or a cold winter.
If you do go ahead with the landscape installation in the middle of the summer, regular watering will be essential to the new plants' survival. Shrubs planted from 3-gallon containers can be established in the North Florida area (north of Orlando) with as little as one gallon of irrigation water applied every eight days. But more frequent irrigation every four days in North Florida has been shown to result in more vigorous plant growth.
Light, frequent applications are much more efficient and effective than applying large volumes less frequently, and micro-irrigation or drip irrigation is highly recommended.
Don't irrigate if a quarter-inch or more rainfall occurred in the previous 24 hours. The shrubs will take 20-28 weeks to become established in the landscape.
The sod will need to be watered every day for the first week. Keep the soil moist for the first seven days after planting, with brief spritzes of water two to three times during the day. This ensures that the soil and sod don't dry out. The sod doesn't require fertilization when it is first installed; wait for a few months before you apply any fertilizer. When you are establishing your new landscape, you are exempt from the local watering restrictions for two months.
Ask your landscaper for specific instructions for getting the plants off to a good start and see if he guarantees any of the planted material. For more information on establishing landscape material, visit the University of Florida IFAS extension website at www.solutionsforyourlife.com.
Q. I recently heard a radio ad saying that the law requires I have a rainfall shut-off device on my automatic irrigation system. Do I really need one, and why?
A. With all the wonderful summer rains we have been getting in North Central Florida, having a rain shut-off device is a great idea. Beyond a great idea, it also is the law.
Florida law requires that any person who purchases and installs an irrigation system must properly install and maintain a functioning rain shut-off device. These devices do just what their name suggests; they shut off the irrigation system when they detect rainfall.
This prevents your sprinklers from irrigating in the middle of a rainstorm or after we have had a heavy rainfall. It also is the right thing to do for the health of your landscape and for our environment.
These rain shut-off devices conserve water by preventing over irrigation when we have been getting enough rain. This prevents overwatering, which can promote diseases in the turf grass. These devices also help to protect surface and groundwater. Surface water runoff and water that percolates deep into the soil can transport excess fertilizers and pollutants into the groundwater and our ponds and creeks. The most common type of rain shut-off device is one that has absorbent discs that expand and contract with collected moisture.
When the discs expand to the preset limit, the irrigation system shuts off. Install the shut-off device where it will be exposed to straight rainfall — not under a tree or in the path of your sprinklers.
It is important to test the device because the one that was installed with your system may or may not be functioning anymore. Using a rain shut-off device saves water and money, and is healthier for your landscape. To learn more about these devices and how to test them, visit the University of Florida's IFAS Extension website at www.solutionsforyourlife.com.
I planted what I thought were green straight cucumber plants from a garden center this spring. They grew well, flowered, but the cucumbers they produced were yellow and shaped like a ball. Did they revert back to a different cucumber type, or did I do something wrong?
If you saved your label or tag, check to make sure you didn't buy lemon cucumber plants. This type has fruit that are round and yellow. If that is not the case, it could be from cultural problems. All vegetables need regular fertilizing as they grow; if the plants were nutrient deficient, it could cause odd-shaped cukes. Irregular watering or moisture stress also can cause fruit to be rounded or deformed. It happens when the plant is somewhat dry when the cucumber is developing, and then when we get a very heavy rain, the cukes blow up like a balloon. To prevent this in the future, maintain good soil moisture by using a drip system on a regular basis. For practical answers to gardening questions, contact the UF/IFAS Alachua County Master Gardeners at 352/955-2402.
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Purple Passion Flower
Rain Shutoff Device